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Solar Powered desalination Plants, Costs and Opportunities in India, solar desalination technologies, solar desalination methodologies, solar desalination costs, solar desalination ibms role, solar desalination india, solar desalination business, solar desalination with csp,

 

TABLE OF CONTENTS

 

1. LATEST NEWS AND VIEWS ON SOLAR DESALINATION 

2. SOLAR DESALINATION DESIGN

3. TYPES OF SOLAR DESALINATION

4. MULTISTAGE FLASH DISTILLATION

5. ION EXCHANGE

6. MEMBRANE PROCESSES ELECTRODIALYSIS REVERSAL, REVERSE OSMOSIS, NANO FILTRATION, MEMBRANE DISTILLATION

7. HUMDIFICATION -DEHUMDIFICATION

8. BE BTECH PROJECTS ON SOLAR DESALIANTION

9. M TECH PROJECTS RELATED TO SOLAR DESALINATION

10. SOLAR DESALINATION RESEARCH PROJECTS

11. SOLAR DESALINATION BUSINESS OPPORTUNITIES

12. COST OF A SOLAR DESALINATION PLANT

13. REGULATIONS ON SOLAR DESALINATION

14. SOLAR DESALINATION HURDLES

 

 



Why Solar seawater desalination can't be done by India!?

 

Speakers at a seminar organised by Gyanodaya Sansthan on World Water Day here Saturday called for exploring new sources of water, including promotion of technology to desalinate sea water with solar energy.

 

Senior advocate K.C. Jain said: "Besides saving water resources, supplies have to be augmented and new water sources added."

 

Activist Kuldip Narain Lal blamed poor management of water resources and corruption in government's canal and irrigation departments for lack of a scientific water management policy.

 

Bankey Lal Maheshwari who runs the Sri Nathji Nishulk Jal Sewa said: "India has abundant sea water resources from Bengal to Gujarat. The technology to convert sea water into potable one has to be developed so coastal towns and those close by get uninterrupted water supply. When Dubai and Singapore can do it, why can't we?" more...

 

Solar Desalination to provide water to farmers in California's central valley

This year, farmers in California's Central Valley will likely receive no water through the federal irrigation program, a network of reservoirs, rivers, and canals that is normally replenished yearly by ice melt from the Sierra mountains.Crippling water shortages have made desalination technology more attractive, including a startup, WaterFX, that uses the sun to produce heat. The heat separates salt and water through evaporation.WaterFX has fewer environmental repercussions than traditional methods of desalination that rely on fossil fuels to generate electricity.The technology could not have come at a better time.

 

No end in sight

 

During a drought-free year, the federally run Central Valley Project provides enough water to irrigate 3 million acres of agricultural land. Last year, farmers only received 20% of their allotment.

 

The lack of water is not just worrying for growers. It affects all people who eat food. One third of the nation's produce is grown in the Central Valley - composed of Sacramento Valley in the north and San Joaquin Valley in the south - and the deep water cuts mean thatmore than half a million acres of crop land will be left unplanted.

 

Some scientists predict California's drought could last as long as a century. Going forward, the state is going to need a substantial water supply that doesn't rely on the aqueduct system, says Aaron Mandell, WaterFX chairman and founder.

 

However, in order to counter California's water problems, the push must be toward renewable desalination plants rather than fossil-fuel dependent facilities that further contribute to climate change. more..

 

 *Fresh water from solar desalination solution for California's drought?

California is experiencing a third year of drought. Researchers studying tree rings found that the last time California experienced a drought this severe was 500 years ago.

California is a leading agriculture producer, and much of that farming takes place in the San Joaquin Valley. Farming and ranching in the San Joaquin Valley requires much irrigation, and irrigation water deliveries are expected to be reduced by 50 percent or more this year. About 2 million acres in the San Joaquin Valley are expected to not receive any water this year under contracts with the State Department of Water Resources or federal Bureau of Reclamation.

The California coastline hugs a huge body of water, the Pacific Ocean, but it is too salty to be used for drinking water or irrigation. Desalination can take that salty water and produce drinking water, but traditional desalination technology is costly and produces large amounts of harmful emissions.

One company just might make desalination less costly to both the bottom line and the environment. The Panoche Water District, a privately held company in the San Joaquin Valley, and WaterFX teamed up to create a solar desalination facility in Firebaugh, Calif. The desalination technology is WaterFX’s Aqua4 technology. The 6,500-square-foot facility in Firebaugh is powered by solar energy and produces up to eight gallons of water per minute from salty water. Plans are underway to increase the facility’s production to 2,200 acre-feet a year.

Firebaugh is located in the western part of Fresno County, an area long plagued with irrigation problems. The Panoche Water District and Drainage District serves over 44,000 acres of the Valley in and around Firebaugh, which includes farms growing almonds, tomatoes, melons, asparagus, pistachios and alfalfa. Panoche gets water from the Bureau of Reclamation out of Shasta Dam in Northern California which travels through the Sacramento River to the Delta region and is pumped into the Central Valley Project delivery system in Tracy, Calif. It then travels about 45 miles to the San Luis Reservoir. There is saline in the irrigated water, and lack of drainage in that part of Fresno County causes a major problem. The saline levels in some of the water have a content greater than seawater.

WaterFX’s Aqua4 system is different from traditional seawater desalination, which is done with reverse-osmosis (RO) process and requires a great deal of electricity. The Aqua4 system uses advanced solar absorption technology and produces more than 200 acre-feet of freshwater per acre of solar collection area. RO needs high pressure to push freshwater through a membrane, and water recovery rate is 50 percent. For every 100 gallons of water processed with RO, 50 gallons of freshwater are recovered and 50 gallons of brine are disposed (causes environmental problems). Aqua4 recovers 93 percent of freshwater. For every 100 gallons treated, only seven gallons of brine are produced.

The brine that is produced has a high concentration of salt (20 percent salt by weight) and using salt separators, solids can be produced from the solution. That is something which is not economically feasible with RO because of the vast amounts of brine. Phase 2 of the Panoche project, expected to be completed by September 2014, will show the types of solid byproducts that can be produced and sold through the Aqua4 desalination system without causing environmental damage. Gypsum, a calcium based salt used to make drywall and plaster, is one example of a byproduct. Another example is magnesium salts, which are in the drainage water and magnesium sulfate is used in the medical industry to treat pain and complications during pregnancy.

 

*WORLDS LARGEST SOLAR DESALINATION PLANT ! TENDER BIDS TO COME SOON!

The UAE would establish world's largest solar-powered desalination plant that will process more than 22 million gallons of potable water per day. 

The new plant at Ras Al Khaimah emirate would also generate 20 MW of electricity. It will implement the most advanced reverse osmosis and filtration technologies and, when operational, will push unit production rates down drastically. 

The plant was announced by private service utility and solutions provider Utico Middle East that aims at setting a desalination business model. Desalination is the process of removing salt and other minerals from saline water more..

 

 Utico earlier this month released the prequalification tender inviting bids for the independent water project, which will be codeveloped by Utico and the winning bidder. The reverse-osmosis plant will output more than 22 MIGD (100,000 m³/d) of potable water and 20 MW of solar power. . SOURCE


 

*FLOATING SOLAR DESALINATION PLANT

contracted Jon Liow to collaborate with them in developing the concept of floating desalination. 

The Waterdome is a conceptual design of a floating solar desalination plant, capable of producing up to 500 litres of drinking water per day. The floating oases, inspired by the organic form of a water lily, utilise solar energy to power patented portable desalination technology, producing fresh drinking water at a rate and efficiency competitive with natural freshwater. The aim is to bring the device to communities who have poor access to fresh drinking water, whilst having access to large amounts of sunlight and seawater. more..
 


 *SAUDI ARABIA TO GET NEW SOLAR DESALINATION PLANT!!!!!

 

The governor of Saudi Arabia’s Saline Water Conversion Corporation (SWCC) said yesterday that the cost of water from a pilot solar desalination project that is now under construction will not initially be a major issue when it comes to assessing the plant’s success.

Dr Abdulrahman Al-Ibrahim said that the use of desalination in conjunction with solar power generation would address the issue of power storage that has previously been a block to major installation of solar power facilities.MORE..


 

 Cucumbers In The Sahara - Thanks To Solar Power

 by Energy Matters

Sahara solar cucumbers
The first cucumbers produced in the Sahara desert using seawater and solar power were served up to participants at UN Climate Negotiations in Doha.
 
Cucumber may be a warm-season vegetable, but the Sahara desert is a rather extreme environment even for this sun loving plant as it is also quite thirsty. 
 
The Sahara Forest Project has combined saltwater-cooled greenhouses, concentrated solar power (CSP), solar panels and desalination technologies to produce the crop from what is otherwise barren land. Salt created from the process is on-sold to third parties. Key to the project is not so much any individual technology, but how they work together. source

 


 

Qatar plans to build an 1,800MW solar-powered water desalination plant intended to meet 80% of the emirate's water needs. sourcesource2 


 

 

 What happens when you combine a Concentrated Solar Power (CSP) array with a water desalination project in the desert? The Egyptian Academy of Scientific Research and Technology (ASRT) is going to spend the next four years finding out as they begin testing a project dubbed the “Multi-Purpose Applications by Thermodynamic Solar,” or MATS. To be located in the desert area of Burj Al Arab, it aims to develop multi-purpose units capable of simultaneously generating electricity from concentrated solar panel arrays while also desalinating water for human consumption. http://revmodo.com/2012/05/18/egypt-testing-combination-solar-powerwater-desalination-units/ 9/5/12


 

*All Saudi desalination will ultimately be solar-powered .

Saudi water desalination is a huge part of its domestic electricity use, and the Kingdom’s Saline Water Conversion Corporation (SWCC) plans to switch this entirely to solar operation. The SWCC operates the 30 publicly-owned desalination plants and a network of pumping stations, reservoirs and all the pipes to transport the water in bulk from the plants to the major consumption centers. Energy is used to desalinate, but it also takes a great deal of energy to move water through the entire Kingdom. The largest city, Riyadh, is very far from the coast.

As the first solar desalination project, next year, the Saudis will flip the switch on the world’s largest solar desalination project, producing 30,000 cubic metres of water per day for 100,000 residents of Al-Khafji near Kuwait. http://www.greenprophet.com/2012/06/details-emerge-of-saudis-109-billion-solar-plan/


 


The four-year project test project, known as "Multi-Purpose Applications by Thermodynamic Solar", or MATS, has received 22 million Euros (US$28 million) from the European Union under its Seventh Framework Programme (FP7), and will also involve European universities and companies.
This will be used to build and test MATS units at a site in Burj Al Arab, a desert area near Alexandria. The units can be powered using both solar energy, and renewable energy sources such as biomass and biogas. The test facility will aim to generate one megawatt of electrical power and 250 cubic metres of desalinated water per day.http://www.evwind.es/noticias.php?id_not=18487


* At present, countries in the Middle East face a major water challenge due to the scarcity and rapid depletion of freshwater resources. This is further complicated by the heavy financial and economic burden in providing desalinated and treated wastewater. ABB’s innovative energy efficient technology for the water industry evoked a lively discussion at the recent event in Doha, Qatar among researchers, executives, decision and policy makers, and other stakeholders on the issue.The conference covered water security and food sustainability, management of natural resources, groundwater and surface water, management of the municipal water sector and desalination technologies – the topic ABB focused on.


 

Solar desalination is a technique used to desalinate water using solar energy. High drinkable water scarcity zones usually correspond to high Direct Normal Irradiance (DNI) areas such as the Middle East. ABB offers products for the complete water cycle from collection, through purification and transportation to distribution and re-use, serving customers with enhanced, efficient and reliable product and solutions. 


 

Focus on energy efficiency

Desalination plants play an essential role where increasing demand for potable water outpaces the availability of natural resources. ABB's portfolio includes a wide range of products and solutions for RO (Reverse Osmosis), MSF (Multi-Stage Flash), MED (Multiple-Effect) and Hybrid desalination plants, with a specific focus on energy efficiency.  more 8/6/12


 

SOLAR DESALINATION PROMISES AGricultural WATER FOR ARID AREAS

The university researchers’ Josefowitz Oasis Project reportedly uses a solar-powered systemwith nanofiltration membranes to treat the local brackish water. The desalinated irrigation water reportedly “yields higher productivity from water and inorganic fertilizers compared with current practices. Crops grown with desalinated water required 25 percent less irrigation and fertilizer than brackish water irrigation. In some cases, the yield of crops increased.” more
Wires turn salt water into freshwaterWires turn salt water into freshwater (a) Seven pairs of graphite rods/wires are dipped into brackish water. (b) An electrical voltage difference is applied between the anode and cathode wires via copper strips, causing the electrodes to adsorb salt ions. (c) Scanning electron microscopy image of the membrane-electrode assembly. Image credit: S. Porada, et al. ©2012 American Chemical Society. more


* HelioAquaTech SolarWaterMaker
The solution of water problems in many parts of the world lies in the use of small, compact and economic systems as offered by HelioAquaTech Corporation Systems, which are completely independent of conventional energy sources, operating exclusively with solar energy and producing 200 to 4,400 liters of water per day, representing economically and ecologically optimal systems for local and regional water supply.


http://www.helioaquatech.com/index.html



*Solar desalination of 30,000 cu ms per day from 2013

Saudi Arabia will build the world’s largest solar water desalination plant by 2013, said Prince Dr. Turki bin Saud bin Muhammad, VP of KACST. The plant will be in the country’s northeastern city of Jubail, with a capacity of 30,000 cu ms/d.
RIYADH — The world’s largest solar water desalination plant will be established in the Kingdom by 2013, said Prince Dr. Turki Bin Saud Bin Mohammed, Vice President of King Abdulaziz City for Science and Technology (KACST) for Research Institutes, while inaugurating an international conference .
The prince inaugurated the Saudi International Conference for Water Technology 2011 on behalf of KACST’s President Dr. Mohammed Bin Ibrahim Al-Suwaiyel, in the presence of the Minister of Water and Electricity Abdullah Bin Abdulrahman Al-Hussayen.

Addressing the conference organized by KACST, Prince Turki said research, development and investment in water technologies was a strategic choice for Saudi Arabia due to the lack of traditional water sources, the high costs of their conservation as well as the high costs of water desalination and treatment.


He pointed out that the King Abdullah Initiative for Water Desalination by Solar Energy is aimed at finding technical solutions for water desalination at low costs to contribute to supporting the national economy.
Prince Turki said that work is currently underway to establish the largest water desalination plant by solar energy in the world in the city of Khafji with a capacity of 30,000 cubic meters per day as a first stage of the initiative which is expected to be completed in 2013 (1434H). — 

http://www.saudigazette.com.sa/index.cfm?method=home.regcon&contentID=20111122112557


*3-day course on Desalination with Solar EnergyAlthough it is in Spain, it is worth it. 
This is a clear future business opportunity. There is going to be need for water in inlands and the only solution is solar desalination and solar pumping from sea shore to inlands. In fact so much water is required, that solar desalination is inevitable.Impress on your boss about its importance and push off to Spain and may be you will also get to see some bull fight there :-)




The European Desalination Society (EDS) has published dates for its series of courses for 2012, which will take place in February, April and June. 

The first, Membrane Technology,
Process & System Design, will be a 3-day intensive course during 20-22 February 2012 in Genoa, Italy.
 The lecturer will be Mark Wilf. 

The seminar topics include practical information about performance and operating conditions of reverse osmosis and nanofiltration technology for brackish and seawater desalting. The program includes introduction to membrane technology, description of commercial membrane elements, illustration of the membrane system design process and overview of systems operation. 

Calculations of the investment and operating cost of membrane plants, based on design cases will be illustrated. A section of the seminar is dedicated to the modern microfiltration and ultrafiltration technology applied for treatment of potable water and as a pretreatment of feed water for RO systems. 

The other courses listed are: 

2-5 April 2012, Genoa, Italy.
 4-day advanced course on Pretreatment, Membrane Fouling and Scaling. Lecturer: Jan C Schippers. 

18-20 April 2012, Almeria, Spain.
 3-day course on Desalination

 with Solar Energy. Lecturers: Julián Blanco, Diego-César Alarcón
 Padilla,
Guillermo Zaragoza. 
4-6 June 2012, Genoa, Italy. 
Intensive Course on
Ion-Exchange Membrane processes: Their principle and practical applications. 
Lecturer: Heiner Strathmann. 

18-19 June 2012 Genoa, Italy. 
2-day intensive course on Thermal Desalination. 
Lecturer: Corrado Sommariva. 

20 June 2012 Genoa, Italy. 1-day intensive course on Material Selection in Desalination.
 Lecturer: Corrado Sommariva. 

21-22 June, 2012, Genoa, Italy. 
2-day intensive course on Water Management and Economics. 
Lecturer: Corrado Sommariva. 
http://www.edsoc.com/

Pos

 


 



*
Floating Solar Cucumbers make drinking water from sea water

New research and innovative projects are paving the way for smaller and more sustainable methods of desalination that could be based locally right in the communities that would most need them. 

An innovative desalination plant design with the potential to help water-starved communities in coastal environments is among the latest designs from concept creator Phil Pauley.

The solar-powered desalination unit turns seawater to drinkable freshwater at source, rather than miles away from the scene of a shortage.

Nick-named ‘Solar Cucumber’, the mini bus unit uses multiple-effect humidification to evaporate and condense seawater while removing its salt content.

Phil runs design and innovation consultancy PAULEY and specialises in design-based solutions and concepts that enhance people’s quality of life and sustainable living.

The Solar Cucumber resembles a giant worktop with a curved glass solar panel top. Inside the floating units, salt water is collected and evaporated in an air-tight vacuum circulated by solar power.

The unit could be deployed floating at sea or on land to provide water in disaster or environmental relief situations.

Increasing water shortages around the world are driving the need for innovative solutions to desalination.

Multiple-effect humidification replicates the normal environmental water cycle. In the case of the Solar Cucumber, it uses solar power and reverse osmosis to separate water from other substances, including salt.

The system uses advanced non-stick-style materials to reduce maintenance and create an effectively self-cleaning system that produces fresh water and sea salt at source while reducing the need for costly and impractical transportation of water.

In permanent off-shore installations, the Solar Cucumber’s anchor system would form part of an artificial reef encouraging the growth of local marine habitats and biodiversity.

http://www.philpauley.com/cucumber.php

http://www.tomorrowisgreener.com/floating-solar-cucumbers-make-drink-water-from-sea-water/

 

Check out the video

http://www.youtube.com/watch?v=ExEBl7WXzAo&feature=player_embedded

 


 

 

*A joint venture between Oakmall Pty Ltd of Queensland, Australia, and Doosan of the Republic of Korea is planning a 265,000 m³/d seawater desalination plant in Cyprus using solar technology. 

This operation will have a zero carbon footprint and utilise solar thermal technology to provide energy for multi-stage flash distillation. 

The site will run as a fully sustainable operation with only two products leaving the site: water and salt. The salt will be recovered onshore for sale to industry. 

http://www.desalination.biz/news/news_story.asp?id=6231&channel=0&title=Australian/Korean JV plans solar thermal desalination plant

 

Visit this blog in the next two days. I will get more info on this JV.

Solar desalination is a great business idea for India as it solves the huge problem that is impenidng. Water. Water in inlands. 

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*The Solar Cucumber turns sea water to freshwater at source, making it much useful to the water starved communities in costal environment. This is how it works.

The mini bus unit is where sea water is evaporated and condensed, the process which helps remove the salt content in water. The unit uses multiple-humidification process, which is more like the normal environmental water cycle.

The Solar Cucumber uses solar power and reverse osmosis to separate salt and other substances from seawater, making it usable.

 

for more info

http://www.greenpacks.org/2011/11/09/solar-cucumber-for-on-the-spot-desalination-of-sea-water/


 


 

 

This concept by designer Joe Kasper is a simple distillation jar. The lower jar is filled with seawater or other brackish water and kept in the sun. 

 

The solar energy causes the water to evaporate and the water vapor condenses in the upper jar as distilled water. 

 

This portable water distiller is especially designed for people living in rural areas near the equator. All they’ve got to do is fill the dirty or saline water into the large container at the bottom and let the sun take care of the rest. When hot sun rays hit this container, the water will start to evaporate as vapor and be accumulated at the small container at the top. At there, they’ll be subjected to condensation and be end up as pure drinkable water.

The designer has named this device Haiti, after the island country that is surrounded by the sea but has severe drinking water shortage.

 

 

 

 

                                                 

 

 

 

                                                

 

c-water’ is a device which produces freshwater. it evaporates sewage, salt water and other watery objects by the use of heat, which is generated from sunlight. it is applicable to wetlands, beaches, boats,  sewage and other places. it has a flexible and compactable design.  The chinese Engineer Chao Gao has designed the so called “C-Water”, an award-winning experimental desalination product that uses solar power to make drinking water. The C-Water system was a recent entry in Designboom‘s Incheon International Design Awards, where its water purification possibilities drew attention due to its simple distillation technique.

 

Indirect solar desalination methods involve two separate systems: the collection of solar energy, by a conventional solar converting system,coupled to a conventional desalination method.Desalination using thermal processes (phase change) can be accomplished using multistage flash distillation (MSF), multiple effect evaporation
(MEE), vapor compression (VC), and freeze separation (FS). 

6.1. Multi-stage flash process


Several medium scale plants for MSF desalination using solar energy have recently been  implemented. Block [6] found that solar-powered MSF plants can produce 6–60 L/m2/day, in comparison with the 3–4 L/m2/day typical of solar stills. One of the most commonly type of solar collectors used are salinity gradient solar ponds, such as the desalination plant in Margarita de Savoya, Italy, with a capacity of 50–60 m3/day, or in El Paso, Texas, with a capacity of 19 m3/day. Another frequently occurring source for solar thermal energy is the parabolic trough collector, which is used in i.e. a MSF desalination plant in Kuwait for a production rate of 100 m3/day [17].

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*Solar desalination plant installed and tested in Coimbatore, Tamilnadu !

 

The successful test proves the effectiveness of the thermal desalination for the exploitation of the solar energy. 

http://www.swsonweb.com/news.asp

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INTRODUCTION

 

Solar desalination as the name suggests is a technique to desalinate water using solar energy. Reverse osmosis and solar humidification – dehumidification are the two major types of solar desalination.In the middle of the 20th century, the world had about 4,000 cubic meters of fresh water per person per year, according to DHI Water Group. Now we’re close, globally, to 1,000 cubic meters per person per year — and 1,000 cubic meters per person per year is defined as water scarcity. 

As said earlier, if you can get water that is meant for drinking at 22 p per litre, isn’t it a great opportunity. That is the cost of the desalinated water. Detailed costing and references are given below.  In this blog, I have given - What is solar desalination, TERI - Solar desalination unit, Solar water desalination plants in Gujarat, Solar powered desalination plant in Saudi Arabia, Portable solar powered water desalination system by MIT, Solar powered water desalination system by MEMSYS, C water solar powered water desalinator for life tracks, Output of large scale solar desalination unit, World's largest solar desalination unit           

This note is meant to list the business opportunity that is there for the Indian entrepreneurs interested in solar energy and in particular solar desalination.As mentioned below, the CM of Gujarat who is pioneering India's foray into the solar scenario is pretty ambitious.Gujarats solar policy is aggressive. It makes a lot of sense to set up a solar desalination plants all along the 1600 km of coastline of Gujarat.It is a business opportunity for all of India. India has a coastline of 6100 km. It is possible to set up a solar desalination on an average distance of 30 km. That means we can set up about 200 solar desalination plants.But the costs that I have talked about ie 20 p per litre of potable water is possible only in large plants. These plants may cost about $ 100 m.I don’t think that should scare anyone so long as you can get saleable water at as low as 20 per litre.Reverse Osmosis is currently the most popular and favoured technology for desalination. Reverse Osmosis is also the most cost-effective. Reverse osmosis is a pressure-driven process. It sort of forces the separation of fresh water from other constituents through a semi-permeable membrane. Solar energy is collected and converted into electrical or mechanical energy to initiate the process. 

 

 

 

The solar humidification-dehumidification (HDH) process is also called the multiple-effect humidification-dehumidification process, solar multistage condensation evaporation cycle (SMCEC) or multiple-effect humidification (MEH). Water is evaporated and then condensed to separate it from other substances. The driving force in this process is thermal solar energy to produce water vapor which is later condensed in a separate chamber as the diagram below explains.

 

 

 

 

 

The Reverse Osmosis Solar Installation (known as ROSI) uses membrane filtration to provide a reliable and clean drinking water stream from sources such as brackish groundwater. Solar energy overcomes the usually high-energy operating costs as well as greenhouse emissions of conventional reverse osmosis. ROSI can also remove trace contaminants such as arsenic and uranium that may cause certain health problems, and minerals such as calcium carbonate which causes water hardness.

 

 

First solar powered desalination plant in India:

In 2006, Barefoot College set up India’s first solar powered desalination plant at a small voluntary organization called Manthan established in Korti. This desalination plant was based on reverse osmosis. This plant is powered by a 2.5KW power plant which helps it to produce 600 litres of water per hour, for 6 hours every day. 

The RO plant reduces the locally available brackish water with a salinity of Total Dissolved Solid (TDS) 4000-6000ppm to 450ppm.

The plant meets the drinking water needs of more than 1,000 men, women and children from Kotri and its surrounding villages. Each family can take 40 litres of water every day for a token amount of Rs.10/ per month.

 

The brackish water, coming to the village through the regular government pipelines, is pumped through the RO plant and is stored in a 5,000 litre tank. The plant consists of a booster pump that costs INR 4,000, a sand filter, a cartridge and a carbon filter that prevents waste and impurities in the water from mixing with the desalinated water. It costs INR.15.5 lakhs to install a mini-RO plant specially designed for operating in a village to bring drinking water to its rural community. 

WATCH Video 

TERI – Solar Desalination Unit:

 TERI designed a solar desalination unit. It is done in collaboration with the Solar Energy Centre of the Ministry of Non-conventional Energy Sources. The prototype has been tried and tested at the Solar Energy Centre. 

TERI’s current solar desalination unit consists of 10 flat-plate solar collectors. It has 4 trays that hold brackish water and a neat and efficient compact heat exchanger in the bottom tray.

 

 

 

 Schematic assembly arrangement of TERI’s solar desalination unit

 

 

 

The unit is pretty capable to deliver 100 litres of water. No-fuss, closed-loop design and the total absence of conventional fuels of this unit makes it totally sustainable, affordable, and totally eco-friendly. The unit is easy to maintain since the system does not depend on pumps or any other active component that requires daily maintenance.

 

Economic analysis of the process establishes that the annual cost of desalinated water from the TERI-SEC prototype desalination system is less than that of water from a solar still.

 

Solar water desalination plants in Gujarat:

 

Gujarat government is planning to develop solar powered desalination water treatment plants on the 1600km long coastline of Gujarat. The desalination plants will be set up in 50 cities across the state. This is a terrific idea as most villages and towns along the coast can get adequate water. Solar power can light up the economies of the coastal villages and towns and what with good drinking water making them highly inhabitable. Gujarat has been in the forefront of solar and is already well known for its forward looking solar policy and its plan for solar city.

 

A mini solar desalination plant has been in operation in Ahmedabad, Gujarat since May 2008. The plant produces pure distilled water from saline ground water. It is also capturing and recycling the solar heat that is stored in the water. The stored energy can be converted to electricity using the ocean thermal energy conversion system.

 

 

World’s largest solar desalination plant - Solar powered desalination plant in Saudi Arabia:

 

Saudi Arabia expects to start its first solar-powered sea water desalination plant by 2013. This will be the world’s largest solar powered desalination plant which will produce 30,000 cubic meters of water for 100,000 people living in al-Khafji, Saudi Arabia.

 

The plant will be powered by ultra-high concentrator photovoltaic technology – a system with a concentration greater than 1,500 suns. IBM has joined with KACST (King Abdulaziz City for Science and Technology) to build the plant.

 

According to KACST scientists, the two most commonly used methods for seawater desalination are thermal technology and reverse osmosis. Both methods are high energy users with costs ranging from 2.5 to 5.5 Saudi Riyals per cubic meter (around US$1.50).

 

So the IBM-KACST team is also working to improve nano membrane technology that filters out salts as well as potentially harmful toxins in water while using less energy than other forms of water purification. The organizations say that by combining solar power with the new nano membrane, they will be able to significantly reduce the cost of desalinating seawater at these plants.

 

Researchers from IBM and KACST developed chlorine-resistant and fouling-resistant polymers that increase the permeability of the membranes without sacrificing selectivity.

 

1                    Basic solar desalination system theory

 

 

 

Basic, traditional solar powered desalination plants are ideal for small scale domestic use in sunny climates because solar power free and the distilled water produced has a high degree of purity.

 

 

 

 

 

 

 

Figure 1. The simplest form of solar desalination unit.

 

 

 

The principle weaknesses of the design are:

 

(i)                 The system is inherently inefficient because a large amount of heat (latent heat of vaporisation) is required to evaporate the water.

 

(ii)               It is difficult to dissipate this low temperature waste heat into the environment.

 

 

 

 

 

 

 

 

 

Figure 2. The heat dissipation problem can be reduced by allowing the condensation to take place in a chamber that is shaded from the direct heat of the sun.

 

 

 

 

 

 

 

Figure 3. The heat dissipation problem can be further reduced by using an optical system to concentrate the solar energy and raise the temperature of the system. The position of the optical system (lenses or mirrors) has to change throughout the day as the position of the sun changes.

 

 

 

These improvements can reduce the heat dissipation issues, but traditional solar desalination plants are commercially uncompetitive because of the latent heat problem.

 

 

 

 

 

 

 

 

 

Figure 4. Even if the water is raised to boiling point using concentrated solar energy, the latent heat problem remains.

 

 

 

 

 

2                    Latent Power Solar Desalination

 

 

 

Key design considerations:

 

 

 

Ø       Simplify the solar tracking system by keeping the optical system stationary and moving the location of the water being heated.

 

Ø       Use lenses instead of mirrors, but keep the weight of glass down by using Fresnel lenses, similar to those used in flat credit card sized magnifying glasses.

 

Ø      Recycle the released latent heat to evaporate additional brine at a slightly lower temperature.

 

Ø      When the temperature falls too low for cost effective recycling of the latent heat, use it to generate electricity using a Latent Power Turbine.

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 5. By using a canopy made up of cylindrical Fresnel thin lenses (i.e., micro prisms) the sun can be tracked throughout the day without the complexity of the moving mirrors commonly associated with large solar power units.

 

The troughs take the form of long (100 metes plus) channels running from North to South. This simplifies the Fresnel lens design because the lens only needs to focus solar radiation in the East to West plain.

 

At any given time, most of the troughs are relatively cool because they are in the optical shade.

 

The design does not require the optical sharpness of a reading glass, so relatively coarse Fresnel lenses can be used. Manufacturing costs per square metre should be similar to bathroom glazing glass.

 

 

 

 

 

 

 

 

 

 

 

Figure 6. A combination of conduits and valves delivers water vapour saturated air from the troughs to an underlying array of condensation chambers. Condensation is only possible in each chamber because the release of latent heat is used to evaporate brine in an overlying chamber. The air gradually cools as it is drawn through the alternating condensation and evaporation chambers by a fan. In order to maintain pressure, the cross sectional are of successive chambers has to fall. 
The coolest moist air emerging from the final evaporation chamber is used to generate electricity using a Latent Power Turbine.
 

 

 

 

 

 

 

 

 

 

Figure 7. This is a vertical cross section through the first pair of condensation and evaporation chambers.

 

 

 

 

 

Q. What happens when the sun goes down?

 

A. We can continue to generate power and potable water using the freeze desalination process.
Dry air LP Turbines can operate below 0oC. This allows them to extract latent heat from brine as pure water freezes out to form ice.

 

 

 

 

 

 

 

3                    Using the the desalination plant as a horticultural glasshouse

 

 

 

The spare space under the roof at ground level can be used as a working area or for growing crops. The cropping area is in the optical shade and remains relatively cool.

 

 

 

 

 

 

 

Figure 8. Pleasantly humid living and cropping zones can be created by adding external glass walls.

 

Larger cropping zones and more intense focusing of solar radiation can be achieved by employing a higher Fresnel lens canopy.

 

The cropping zones are only illuminated by scattered sunlight from the sky. In effect, the inner glazed zone, occupied by the troughs, acts like a giant heat pump, shunting heat away from the cropping zones.

 

Plants can also provide natural air cooling: (i) Photosynthesis will convert about 10% of the solar energy falling on to the leaves in to chemical energy inside the plants. (ii) Evaporation of water from the leaves of the plants provides further cooling. This system will allow people to work comfortably in hot regions, with minimal need for air conditioning.

 

 

 

 

 

 

 

Figure. 9. Parallel solar desalination units may be added as required 
There will be an upper limit for this type of colony if the presence of glass houses creates a cloudy micro-climate.

 

 

 

 

 

Figure. 10. If land space is scarce, pontoon systems can be used.

 

 

 

4    A simplified system for small scale units

 

 

 

Key by-product features
Using a heat exchanger for the condensation process, this system could provide heat for cooking food and the  sterilisation of bacterially polluted water or sewage.

 

 

Figure. 11. The hot steam plus air output is passed through alternating condensation and evaporation chambers, 
                 as in figures 6 and 7.

 

 

 

5    A closer look at the canopy

 

 

 

Figure. 12.  Flat backed Fresnel lenses are easier to cast and pack for shipping to the building site.

 

As a bought in product, polycarbonate is currently cheaper than glass. But, if the raw glass making materials can be sourced locally and solar powered Latent Power Turbines are used to generate electricity for the manufacturing process, glass will work out cheaper for very large scale plants.

 

 

 

6    Ventilating the living and cropping areas

 

 

   

 

 

 

Figure. 13.  Evaporative cooling is used to cool and moisten the air entering into the enclosed area under the canopy. This process also takes the chill off the raw brine before it enters the solar evaporation troughs.

 

 

 

7   Taking the design concept forward - Student projects?

 

Before building a prototype system, proof of principle experiments will need to be carried out in the laboratory.

 

7.1 The primary solar evaporation system
In order to minimise construction costs and the size of the rig, the water could be heated directly, instead of using Fresnel lense 

 

Figure. 14.  The first round of experiments can be done indoors using heating elements to model the input of solar energy. 

 

7.2 The array of secondary condensation and evaporation chambers.
It is only necessary to build a single pair of secondary condensation and evaporation units as shown in Figure 7 above. 
 In the first round of experiments pure steam at (stagnation) atmospheric pressure would be drawn into the system using an exit fan. 
The exit temperature and dynamic pressure would be noted and used as the inlet temperature and fractional steam pressure for the second experiment.
In the second round of experiments, the steam would be bulked out by adding sufficient warm air that the mixture was entering at (stagnation) atmospheric pressure and its dew point. Courtesy

 

 

 

8 An alternative to the Fresnel lens canopy

 

On our Latent Power Turbine page we suggest a glasshouse system that uses ordinary sheet glass instead of Fresnel lenses. 
This simplified system is cheaper to build, but is not very efficient for distilling water.

 

 

 

Figure. 15.  This appears as Figure 1 on our Latent Power Turbine page .

 

Portable Solar-Powered Water Desalination System by MIT:

A team from the Field and Space Robotic Laboratory of Massachusetts Institute of Technology (MIT) has designed a solar-powered water desalination system which can be easily packed up for delivery to emergency areas.

 

 

 

The system’s photovoltaic panel is able to generate power for the pump, which in turn pushes undrinkable seawater through a permeable membrane. Once the salt and other minerals are removed, the water can then be drunk. The system even has sensors that enable water purification even without high levels of sunlight.

 

The water desalination system produces 80 gallons of drinking water per day, depending on weather conditions. A larger version is also being designed, which will cost $8,000 and will be able to provide 1,000 gallons of water daily.

 

Solar Powered Water Desalination System by Memsys:

 

Memsys, Singapore developed a new technology called vaccum multi-effect membrane distillation which combines the two most popular forms of desal tech, thermal distillation and membrane distillation. The desalination unit is completely mobile, does not require any external parts, and fits inside a 20-foot shipping container. It is powered using both solar thermal and solar PV, and requires little maintenance. Unlike existing desalination technology, it does not need chemicals, diesel generators, or any other external power. Depending on the amount of sunlight, it is expected to produce, on average, 1000 litres of drinkable water per day.

 

 

The special process combines thermal distillation and membrane distillation, the most common process used by desalination systems. Water is boiled in a small vacuum at lower temperatures, 50-80 degrees Celsius (or 122-176 Fahrenheit), and the steam is passed through several membrane distillation stages, also at lower temperatures and pressures. Energy is recovered after each step in order to power the next, making it a far more efficient system than current technologies. The system is also able to handle very high salt concentrations, like those found in saline groundwater.

 

 


 

 

Product specifications http://www.memsys.eu/dateien/applications-products/desalination/memDES_01_en.pdf

 

C-Water: Solar Powered Water Desalinator for Life Rafts:

 

Chinese Engineer Chao Gao has designed an award-winning experimental desalination product called C-water that uses solar power to make drinking water. Its distillation technique is very simple.

The C-Water can be placed on a damp surface or on the water in direct sunlight and, like a greenhouse; it uses solar rays to heat the water, separating out any impurifications. The evaporated water vapor then condenses on the C-water’s roof, where it is collected in a separate area. Within 47 hours the unit can produce enough fresh water.

 

The device could also be deployed a larger scale to produce great amounts of water, but for now the idea is being discussed as a life-saving solution for life rafts.

 

Output of large scale solar desalination plant:

 

A theoretical proposal is outlined for large scale solar desalination using multi effect humidification. It involves the use of a large area solar collector, multi effect distillation and boiling at reduced pressure. The configuration devised is a circular tank of one kilometer diameter containing water to a depth of 10 meters with a sealed double glazed dome, operating at 0.1 atmosphere pressure with a working temperature below 50° C. A solar absorber placed just above the water level, abundantly perforated but covering the entire area, sets up convection currents that evaporate the sea water and condense the vapour. Incoming seawater recovers energy from outgoing clean water and brine in a counter current heat exchanger. Water flow is driven by solar distillation and hydrostatic pressure. It is estimated that the structure would have 95% energy efficiency and a gained output ratio of 20. In sunbelt countries with average isolation of 6kwh/m2/day the desalination plant would produce 100,000 m3/d distilled water at a speculative cost of $0.28/m3. 

 

 

Consider the desalination plant described in Figure of diameter 1 kilometer.

Area solar absorber πr2 = 3.14 x 0.5 x 0.5 = = 0.785 km2  

In sunbelt countries average annualised insolation is 6kwh/m2/day

Assume 80% transmittance through glass

90% efficiency solar absorber

Total solar energy absorbed = 0.8 x 0.9 x 0.785 x 106 x 6000 x 60 x 60 = = 12 x 1012 joules/day

Energy required to heat 1 gram water from ambient temperature to 50° C and to evaporate = 30 540 calories

                                                                                                                                                                          = 570 x 4.2 joules

                                                                                                                                                   = 2,400 joules

 

But if there is a gained output ratio of 20

Actual amount of energy consumed per gram water desalinated is 120 joules

Thus mass of water desalinated is 12 x 1012/120 grams/day = 100 million litres/day

                                                                                                  =100,000 m3/d

 

Such a capacity would be comparable to some of the world’s largest desalination plants. Note that water demand in the UK is 150 litres/day and in developing countries 10 litre/day per person. The desalination plant above would meet the daily demand of 600,000 people in an advanced country or 10 million people in the developing world.

 

Cost of desalinated water:

 

One can only hazard a guesstimate cost for the plant described above to give an order of magnitude figure. The installation is very large but technically very simple with nothing that is high tech. Let us say that construction would cost $100 per square metre giving a total cost of $100 million.

 

If the capital cost is discounted over 10 years with average production of 100,000 m3/d, then the capital cost is equivalent to

$ 100million = $0.28/m3

100,000 x 365 x 10

The cost of desalinated water from the world’s most recent large plants is about $0.5/m3

The running costs of the solar desalination plant would be very low with its fuel free. This order of magnitude calculation indicates that large scale solar desalination could compete with present desalination technologies.

These costings are not tested. Yet.

Source:http://bit.ly/aNLkCh 

All the above information about the costs of solar desalination helps, entrepreneurs in gujarat, maharastra, Rajasthan, Tamilnadu, Karnataka, Kerala, Andhra pradesh, Orissa, West Bengal - the coastal states for setting up coastal solar desalination plants.

 

Given below are additional links for you to calculate the costs in detail. Shuweihat Water Transmission Scheme, United Arab Emirates:http://www.water-technology.net/projects/shuweihat/

Full Specification: 
http://www.water-technology.net/projects/shuweihat/specs.html

Transmission Pipeline costs
http://www.costwater.com/pipelines.htm

 

First Esco India Pvt Ltd:

First Esco India Pvt. Ltd is an importer and exporter engaged in offering solar desalination plant. These are manufactured by recognized vendors using premium quality material at par with International standards.

http://firstesco.tradeindia.com/Exporters_Suppliers/Exporter31756.672445/Solar-Desalination-Plant.html

 

 

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24 Comments

  • shankar
    shankar -

    http://refriend.en.hisupplier.com/product-332994-solar-desalination-system.htmla manufacturer from china. not sure about quality/ reputation/ just saw one while browsing. Like

  • aathmika
    aathmika -

    Exergy and thermo-economic analyses of a combined solar organic cycle with multi effect distillation (MED) desalination process


    Research Highlights

    ► Different configurations of MED desalination process are compared. ► Parallel feed configuration could be dominant while increasing the number of effects. ► Combining solar organic cycle with such configuration is required. ► The combination is evaluated based on exergy and thermo-economic analyses. ► Stand alone technique harvests lower solar field area and higher gain ratio.


    http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFX-5230FFM-4&_user=10&_coverDate=05%2F03%2F2011&_rdoc=1&_fmt=high&_orig=gateway&_origin=gateway&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=4a59ec3603b7663b88d4710bdf276817&searchtype=a




    Experimental and Theoretical Study of an Optimized Integrated Solar Desalination and Air Conditioning Unit

    The objective of this work is to model and optimize the operation of a combined air conditioning unit and solar distiller still to enhance distillate output and system performance to meet a specified cooling load and fresh water needs of a residential application. Simulation models have been developed for the solar distiller and cooling coil of the combined system. The developed models were experimentally validated. The combined distiller and cooling coil model predicted well the condensate volume over half-hour intervals with less than 5%. A computationally efficient optimization tool of the combined system operation is developed using statistical correlations for solar still performance parameters based on data generated by the validated simulation model. The optimization problem of the combined solar distiller and air conditioning system operation is solved for a residential application of peak cooling load of 5.4 kW with distilled water demand of 100 l/day over 10 hr of combined system operation. It is found that the optimal operation total energy consumption varied between 21.34 and 23.80 kWh/day. The fresh water energy cost ranged from 0.11 to 0.12 kWh/liter over the cooling season and is found lower than the cost of stand-alone water production from atmosphere machines.

    http://www.informaworld.com/smpp/content~db=all~content=a933378019

    Like

  • Nithya
    Nithya -

    40% of the worlds population lives without potable water and about  80 000 habitations around the world have no source of safe water. In India, about 162 000 face problems of brackish or contaminated water and scarcity of fresh water.

    In urban and rural areas of India that have access to water, a sizable population has, for generations, been drinking water with TDS (total dissolved solids) levels of about 1500 to 2000 mg/litre (milligram per litre) though the BIS (Bureau of Indian Standards) specifications for drinking water limits the amount of TDS at not more than 500 mg/litre.

    India has about 53 000 habitations with salinity greater than 1500 mg/litre, most being remote and arid areas with saline water.


    Absence of electricity, heavy investment, and the polluting nature of fossil fuels have made it difficult to work wth  regular desalination technologies in rural India. The  basin-type solar still is the only commercially available solar device to desalinate water. This hardly  delivers 2.02.5 litres of water at a time and costs 5000 rupees. It is not good enough.






    Conventional multistage desalination plants  pose problems due to the  need for high temperature and vacuum.

    TERIs current solar desalination unit consists of 10 flat-plate solar collectors, 4 trays that hold brackish water, and an efficient and compact heat exchanger in the bottom tray.



    Schematic assembly arrangement of TERI's solar desalination unit

    The unit is designed to deliver 100 litres of water, translating to 42% more output vis--vis the commercially available single-basin solar still. Though the process of desalinating saline water evaporating water, condensing and collecting pure water vapours remains the same, what makes all the difference is its no-fuss, closed-loop design and the total absence of conventional fuels, thus making it totally sustainable, affordable, and eco-friendly.

    Although this is recommended for coastal areas too, I would recommend these for inlands.




    .
    Like

  • aathmika
    aathmika -

    SPX  offers various soltions. But there solar desalination solution is not complete or that page is not filled in.


    SPX Tracker UF


    Ultra Filtration Systems for non-brackish water

    The SPX Tracker UF (ultra-filtration) Systems are high efficiency, high value solar powered water filtration systems designed to remove virtually all suspended solids and bacteria from non-brackish surface water sources.

    The UF systems are mounted on reinforced mobile trailers and are capable of being pulled by standard motor vehicles. The mobility of the systems allows them to be easily deployed in rural communities or large urban environments within a matter of hours.

    Solar power provides independence of electrical or water grids, creating an immediate solution to the clean drinking water needs in areas where there is little or no operating infrastructure.

    SPX UF systems utilize a patented tracker system that allows the solar panels to track the sun throughout the day. This tracking feature increases water production by up to 40% versus typical fixed tilt solar systems and allows the system to operate for up to 20 years.

    System Output Levels (liters / gal per hour):

    • Tracker UF 1M3: 1m3 / 1000 lph / 264 gph
    • Tracker UF 3M3: 3m3 / 3000 lph / 792 gph
    • Tracker UF 5M3: 5m3 / 5000 lph / 1320 gph
    • Tracker UF 10M3: 10m3 / 10000 lph / 2640 gph



    Output Water Quality:

    • Total Suspended Solids (TSS) filtration to less than 5ppm
    • Turbidity to less than 0.5 NTU
    • 99.99% bacteria free



    Other Key System Features:

    • Patented tracker system with early wake-up functionality
    • High efficiency solar panel array
    • Entire water system and ancillary electrical components fully enclosed to protect against unauthorized access, dust, heat and other elements
    • Ultra efficient multi stage filtration process with automated flushing of all stages
    • DC powered ultra efficient submersible pump
    • State of the art, microprocessor controlled system operation
    • Automatic low pressure shutdown and re-start
    • High pressure system bypass protection
    • Surge and lightening protection
    • Integrated battery back up system
    • UV post treatment to eliminate bacteria
    • Metered flow chemical injection system
    • Thermostatically cooled water system enclosure with automatic activation



    SPX realizes the unique requirements of each deployment and maintains the capability to custom design these systems to meet local needs and conditions.

    ---------------------------------------------------------------------------------------------------------------------------

    SPX Tracker RO


    Desalination Systems For Brackish Water

    The SPX Tracker RO (reverse osmosis) systems are high efficiency, high value solar powered water filtration systems designed to remove virtually all dissolved solids and bacteria from brackish, surface and well water sources.

    The RO systems are mounted on reinforced mobile trailers and are capable of being pulled by standard motor vehicles. The mobility of the systems allows them to be easily deployed in rural communities or large urban environments within a matter of hours.

    Solar power provides independence of electrical or water grids, creating an immediate solution to the clean drinking water needs in areas where there is little or no operating infrastructure.

    SPX RO systems utilize a patented tracker system that allows the solar panels to track the sun throughout the day. This tracking feature increases water production by up to 40% versus typical fixed tilt solar systems and allows the system to operate for up to 20 years.

    KEY FEATURES

    System Output Levels (per hour):

    • Tracker RO 1M3: 1m3 / 1000 lph / 264 gph
    • Tracker RO 2M3: 2m3 / 2000 lph / 512 gph
    • Tracker RO 3M3: 3m3 / 3000 lph / 792 gph
    • Tracker RO 5M3: 5m3 / 5000 lph / 1320 gph


    Output Water Quality:

    • Total Dissolved Solids (TDS) filtration to less than 500 mg/L
    • Turbidity to less than 0.02 NTU
    • 99.99% bacteria free


    Other Key System Features:

    • Powerful and efficient pumping systems capable of delivering water from depths of up to 150m.
    • Thin Film Composite Membranes
    • High strength membrane pressure vessels
    • Permeate, concentrate and recycle flow meters
    • Stainless steel system and recycle control valves
    • Low pressure pump protection
    • High efficiency, patented tracker system with early wake-up functionality
    • Enclosed water / electrical systems to protect against unauthorized access and elements
    • State of the art, microprocessor controlled system operation
    • Surge and lightening protection
    • Integrated battery back up system
    • SPX MF / UF pre-filtration technologies for maximum protection of the RO membranes.
    • Robust, multistage suspended solid filtration solution for surface water applications.
    • Proprietary pre- filtration for extended pump life
    • Thermostatically activated cooling system for automatic enclosure cooling


    SPX standard systems are designed to operate with brackish input water of 500 TDS. However, SPX realizes the unique requirements of each deployment and maintains the capability to custom design these systems maximize efficiencies while meeting local needs and conditions.

    ---------------------------------------------------------------------------------------------------------------------


    SPX Tracker SW


    Desalination Systems For Sea Water

    SPX is working with cutting edge technologies for our latest breakthrough, the SPX Tracker SW series. Expect exciting announcements in 2010.

    -----------------------------------------------------------------------------------------------------------------------------

    SPX Tracker AG[Translate]


    Ultra-efficient Irrigation solutions

    SPX AG systems incorporate SPX solar pumping strengths with industry leading drip irrigation. SPX AG systems are designed to operate independently with minimal maintenance and to deploy in worldwide locations within 1000 meters of fresh water source. Each system employs our solar tracking technology and DC powered pumps to provide efficient water transportation and irrigation of various crops. These modular systems can be employed individually or in series to cover larger areas of land. The individual systems provided by SPX deliver drip irrigation for 0.25 / 0.5 / 0.75 or 1.0 acres of row or permanent crops. All systems have been designed with simplicity and durability in mind, are easy to deploy and require very little maintenance. They are completely self-contained from a power stand point and demonstrate a very high return on investment (ROI) and quick payback of investment when compared to traditionally powered systems.


    Like

  • Nithya
    Nithya -

    Local model predictive controller in a solar desalination plant collector field

    I found it as an interesting patent and hence posted it here for those who are pursuing this opportunity of solar desalination seriously.

    Nithya


    Abstract

    This paper proposes a new predictive control strategy for a distributed collector field of a solar desalination plant. The main purpose of the controller is to manipulate the water flow rate to maintain constant the outlet-inlet temperature gradient in the collectors in spite of disturbances. The controller is based on a filtered Smith predictor generalized predictive control algorithm and a simple procedure to update the linear model used in the predictor as well as the tuning parameters, in such a way that non-linear optimization is avoided. The controller copes with the process non-linearities, constraints, dead time and plant-model mismatch obtaining the desirable performance both, in the reference tracking and in the rejection of strong irradiance disturbances. Simulations and real experimental tests in AQUASOL desalination plant solar field are presented to show the advantages of the proposed controller.

    Highlights

    ►Predictive control strategy for a distributed collector field of a solar desalination plant. ►Controller coping with the process non-linearities, constraints, dead-time and plant-model mismatch. ►Desirable performance both, in the reference tracking and in the rejection of strong irradiance disturbances. ►Experimental tests in AQUASOL desalination plant solar field.

    http://www.sciencedirect.com/science/article/pii/S0960148111001649

    Like

  • Joydeep
    Joydeep -



    The new solar desalination  plant coming up in Saudi Arabia,  will operate using a PV concentration technology developed by none other than Big Blue himself, aka IBM.


    The technology focuses 2,300 times the power of the sun onto a a single square-centimeter solar cell.

    The cell doesnt get damaged because of an indium-gallium liquid-metal alloy that acts as a heat sink, by moving the heat away from the cell. In addition to the new PV technology, the plant is also using a new reverse osmosis based water filtration system, also developed by IBM and University of Texas at Austin.

    Energy use takes up more than half of the cost of running a desalination plant, and current desalination plants rely on fossil fuels for that energy.


    Even though solar power is still more expensive than fossil fuels in most places, the long term savings costs make it an ideal solution for such a project. In addition, the substantial reduction in greenhouse gas emissions is just another great perk of such a system.


    Completion for the plant is scheduled for 2012, and when completed, the plant will produce 30,000 cubic meters of desalinated water per day, which is enough to meet the basic needs of 100,000 people.

    Like

  • aathmika
    aathmika -

    Saltworks, based in Vancouver, has developed an energy efficient way to convert salt water into fresh water through desalination.

    The companys technology removes salt from seawater and underground saline (brackish) water by harnessing low-temperature heat provided by solar energy or waste heat from power generation, which reduces the amount of mechanical and/or electrical energy required.

    Potential applications for Saltworks' technology include processing water for industry, as well as producing drinking water for communities and irrigation water for agriculture.

    The Thermo-IonicTM process works by first evaporating salt water to air to create a hyper-salty solution which holds energy relative to the original salt water. Evaporation is achieved in a modified cooling tower or spray pond by harnessing low grade heat from renewable sources such as the sun or waste heat rejected by an industrial process. The hypersaline and original salt water solutions are fed into Saltworks' proprietary desalting device where the potential energy from the difference in their concentrations is used to drive salt ions from a third desalination product stream.

    Saltworks' process employs an innovative thermo-ionic energy conversion system that harnesses solar energy to drive the desalting process. Applications for Saltworks' technology include producing drinking water for communities and municipalities, irrigation water for agriculture, and process water for industry.

    This is an opportunity. Get in touch with Saltworks technologies.
    To market their products. To set up a solar desalination plant in India.
    Or whatever.

    Like

  • shankar
    shankar -

    By 2012, the Kingdom (Saudi Arabia) hopes to open the worlds largest solar powered desalination plant in the city of Al Khafji. Spearheaded by the King Abdulaziz City for Science and Technology, the project aims to supply 30,000m3 of clean water per day. Like

  • shankar
    shankar -

     The chief minister apprised Sagir about the state's initiatives to set up solar desalination plants along the coastline of Gujarat. 
    The envoy had evinced interest in states water management projects, initiatives like Krishi Mahotsav for agriculture promotion, and forensic science university set up here, the statement said.
    http://ibnlive.in.com/generalnewsfeed/news/israel-explores-possible-business-ventures-in-gujarat/672115.html Like

  • shankar
    shankar -

    The opportunities regarding solar desalination are galore. Aathmika seems to believe in leaving the opportunities unsaid.
    Even buying property along the coastal villages is an opportunity.
    Becoming an agent of SPX AG is an opportunity.
    Given that water and electricity are going tobe available in coastal villages - planning small scale units like Freezers for the fishermen, can be an  opportunity.
    Large CPVs  can provide electricity, new residential colonies with BIPV, can be planned along the coast.
    It is important to plan mega desalination plants so that water can be pumped inlands for drinking as well as for some low water consuming agriculture. Like

  • shankar
    shankar -

    A Stake in Two Boom Industries

    Between now and 2030, roughly $25 billion must be invested to ensure Australia has adequate electricity. A similar amount must be spent upgrading the nation's water infrastructure. Globally, the International Energy Agency estimates US$20 trillion (yes, trillion) must be spent between now and 2030 just on electricity infrastructure to ensure the world has enough power.

     Clearly, supplying sufficient energy and water for the world's population is shaping up as a major challenge for the 21st Century. In some places, these two needs can be satisifed through one combined solution:

     solar-powered desalination.

    Like

  • anna
    anna -

    Amy Childress, a professor at the University of Nevada Reno, and a group of researchers are experimenting with a method that essentially harnesses the hidden power of waste streams to turn sea or swamp water into something you could possibly drink.

    In theory, it could offset 50 percent of the energy required in reverse osmosis (RO)  desalination, she said. 

    That makes it even better. As per my earlier calculation, Nithya was getting desalinated water at 22 paise per litre. And her improvised version was costing 5 p per litre. With this it may come down even further. 

    The fifty percent figure is just in theory, she added for further emphasis, but any progress in reducing the power consumed in desalination would be welcome. Energy -- which is used to pressurize water so that an RO membrane will fleece the salt and other impurities -- can account for around two-thirds of the operating costs of a desal plant, according to general industry estimates. ("Current electricity use in seawater RO plants, including pretreatment, is approximately 3.73 kWh/ m3, with approximately 2.41 kWh/ m3 for the RO separation. The lowest demonstrated use for RO, excluding pretreatment, has been just below 1.6 kWh/ m3," wrote Aaron Mandell and Rob McGinniss from forward osmosis company Oasys in a recent article for us.)


    The UNR concept works as follows. A standard RO plant for converting seawater into fresh water would be erected. It would function like a standard plant. Next to it would be a pressure retarded osmosis (PRO) plant. In this plant, lightly- to moderately-fouled water like sewer water would be directed to a reservoir. At one end of the reservoir would be an RO membrane. On the other side of the membrane would be an extremely salty solution. It could be the brine discharge from the principle RO plant.

    Nature, and water, seek an equilibrium, so the lightly salted water would push itself through the membrane to the briny side in a vain effort to achieve saline equilibrium. The flow of water to the briny side would create pressure. Think of what happens when you eat salty food and get the sudden urge to drink water. You get bloated and distended. Same thing happens here.

    In a PRO plant, however, that pressure could be used to pressurize water flowing into the main osmosis plant. (One could also insert a water column between the moderately- and seriously-fouled water supplies and get the same results.) In the end, you essentially exploit two dirty sources of water to recycle another one. 

    The technique shares a lot in common with other desalination concepts we've covered here.Energy Recovery, for instance, harvests the pressure from discharged waste streams in RO plants to pressurize incoming water. The pressure harvested by Energy Recovery comes from the mechanical pressure applied to the water and not chemical/physical attraction, and it must be harvested from the waste streams as they jet from the RO plant. Thus, you could combine and Energy Recovery system with this technique.

    Oasys, meanwhile, takes advantage of chemical attraction with its forward osmosis technology. Oasys uses chemical attraction for osmosis itself and not pressure harvesting. Finally, it's also like the osmotic pressure gradient created by Statkraft. in an ongoing trial in Norway, Statkraft harvests the pressure created by fresh water crossing a membrane to produce electric power. Childress and her group are doing the same thing, but instead of turning the pressure into power, and thus losing some energy in the conversion, they are directly using the pressure. (Childress pointed out that UNR's system and the Statkraft system are currently the world's two osmotic pressure gradients.)

    "The main advantage is to produce drinking water at a reduced cost. Other benefits include brine dilution prior to ocean discharge and concentration/treatment of the impaired water source," wrote Andrea Achilli, a graduate student on the project in an email after our field trip. "It is also worth noting that the RO feed water is not diluted with impaired/waste water; it is comprised of only seawater, so this system does not represent a direct or indirect water reuse system. We simply recover the chemical water potential of the impaired water and transfer it to the seawater."

    Childress is also conducting experiments on thermal desalination in which low-grade geothermal heat can be injected into salt at the bottom of reservoirs. Last week, I spent some time in Nevada and have some geothermal stories coming up. (Disclosure: I grew up in Reno, but, no, I do not carry money around in a big plastic bucket.)

    Final extra tidbit: this piece of machinery comes from Childress' lab. NASA used to own it. Remember those experiments to develop drinking water from the urine of astronauts? You're looking at the machine that NASA employed.

    Like

  • anna
    anna -

    http://www.greentechmedia.com/articles/read/a-new-tool-for-desalination-sewer-waters-storm-runoff/ Like

  • Nithya
    Nithya -

    Commercial desalination is usually done in one of two ways. The first, known as thermal desalination, involves boiling seawater above 212F, then distilling the vapors. The second, called reverse osmosis, uses hydraulic pressure to force water through a membrane that filters out salt. Both require enormous amounts of energy. McGinnis says he's found a method that's at least 10 times more fuel-efficient.



    Water molecules naturally want to flow from fresher solutions to saltier ones. Hence the "reverse" in reverse osmosis: It forces water molecules to go against their tendency. McGinnis's method makes use of forward osmosis. He's developed a "draw solution" that's saltier than seawater. Without need for any energy, the water molecules in seawater flow across a porous membrane and into the draw solution, leaving the sea salt behind. McGinnis's solution is as undrinkable as ocean water, but its salt compounds"essentially just ammonium, carbon dioxide, and some other secret stuff," he saysvaporize at lower temperatures. McGinnis's solution needs only 122F to burn off salts and leave behind pure water, instead of the much higher temperatures required for thermal desalination.

    After graduating from Yale with a PhD in environmental engineering in 2009, McGinnis co-founded Boston-based Oasys Water and raised $10 million from three venture capital firms to commercialize the technology, including developing a thin membrane suitable for forward osmosis. Oasys plans to start taking orders in late 2011. "Forward osmosis is on the verge of becoming a buzzword," says Tom Pankratz, director of the International Desalination Assn. "Oasys has a clever approach. ... It could potentially be used not only for seawater desalination but also treating wastewater."

    McGinnis didn't plan to dedicate his career to desalination. As an undergraduate he majored in theater and wrote "sci-fi coming-of-age think-piece mini-epics," he says. Even then, he spent three nights a week working on desalination experiments, often after late-night play rehearsals. "I just couldn't accept the idea of trading fuel for water," he says.

    http://www.businessweek.com/magazine/content/11_12/b4220041560310.htm Like

  • dheen
    dheen -

    Solar panels commissioned at UK desalination plant

    Tuesday, Aug 09, 2011

    Thames Water in the UK at the end of July commissioned a 450 kW array of solar panels at its 150,000 m/d Beckton brackish-water desalination plant as part of a bid to become Britain's biggest on-site solar power producer and industrial user. 

    Under a 7 million 25-year contract, Ennoviga Solar Ltd, a specialist photovoltaic developer, has created an investment company that will own and maintain solar arrays at three Thames Water sites, repaying the investment by selling all the clean electricity produced to the water company at a market-competitive price. 

    Dr Piers Clark, commercial director at Thames Water, said, "With the price of energy forecast to increase above inflation, the way we've structured this agreement will give us cheaper, renewable source of power from a secure source over the long term." 

    The Beckton desalination site (see D&WR cover feature August/September 2010) will generate 385 MWh/year on average, while 150 kW arrays installed above ancient storm tanks at Crossness sewage works and redundant sand filters at Walton water treatment works will each generate 133 MWh/year on average, enough to power 140 average-sized homes. 

    Crossness and Walton will eventually be expanded to 1,700 MWh/year and 3,000 MWh/year respectively. Thames Water has set a voluntary target of reducing its greenhouse emissions by 20% in real-terms on 1990 levels by 2015. 

    http://www.yourrenewablenews.com/solar+panels+commissioned+at+uk+desalination+plant_66837.html Like

  • solar1234
    solar1234 -

     Solar Powered desalination Plants are still very expensive. For small scale application in remote areas OK but not at large scale.

    Dr.A.Jagadeesh Nellore (AP)

    E-mail: anumakonda.jagadeesh@gmail.com


    Like

  • Nithya
    Nithya -

    The Egyptian Academy of Scientific Research and Technology (ASRT) has announced the launch of a pilot Concentrated Solar Power (CSP) project to test units that can simultaneously produce electricity and desalinate water. 


    The four-year project test project, known as "Multi-Purpose Applications by Thermodynamic Solar", or MATS, has received 22 million Euros (US$28 million) from the European Union under its Seventh Framework Programme (FP7), and will also involve European universities and companies.

    This will be used to build and test MATS units at a site in Burj Al Arab, a desert area near Alexandria. The units can be powered using both solar energy, and renewable energy sources such as biomass and biogas. The test facility will aim to generate one megawatt of electrical power and 250 cubic metres of desalinated water per day.

    In a statement, Maged Al-Sherbiny, the ASRT's president, said that MATS units could be used to exploit "concentrated solar energy through small and middle scale facilities, to fulfill local requirements of power, heat, and desalinated water".

    "ASRT is the main contract holder for the project, with other partners from Italy, Germany, France and the United Kingdom," Al-Sherbiny told SciDev.Net, adding that an agreement to host the project has been signed with the City of Scientific Research and Technological Applications (CSRTA), which has allocated the land in Burj Al Arab.

    Essam Khamis, head of CSRTA, told SciDev.Net that "this pilot project will [also] be a research station as it will include a specialised research institute in which Egyptian researchers will be trained".  http://www.enn.com/business/article/44390

    Like

  • Nithya
    Nithya -

    Solar powered water desalination system  http://www.tvsolar.com/view/10826/portable-solar-powered-water-purification-desalination-system/

    Designing a desalination plant : course  http://www.youtube.com/watch?v=_GcjR0QN6qk



    Solar DesalinationDr. Senthilmurugan ABB 23, April, 2012Important Technology Aspects

    Around 12.200 desalination plants under construction or in operation globally (out of around 16.000)§ Technology§ Thermal (MSF, MED): around 1.250§ Membrane (RO, NF): around 10.000§ Hybrid; around 50• Other: around 900 (e.g. ED, EDI)• Capacity• Small scale : around 11.000 plants• Medium scale: around 950 plants• Large scale: around 250 plants• Geography§ Americas: around 2.800 plants§ Asia Pacific: around 3.150 plants§ Europe: around 2.250 plant§ Middle East, Africa: around 4.000 plants






    -------------------------------------
    For rural municipal water applications, the emphasis will be on solar desalination technologies such as solar distillation, multiple effect dehumidification, membrane distillation, RO etc., and will require smaller CapEx investments. § Although such units can be operational only during daytime, simple storage options such as hot water storage and/or batteries can ensure continued production when Sunlight is not available. § These technologies have advantages such as variable capacity operation, capability to use waste heat, lower operation and maintenance cost, ease of operation, etc. § In addition to this, the poor infrastructure, lack of grid connectivity, nonavailability of high skilled labor, etc., in a rural environment further favors application of these technologies at the desired small scale capacities

    -----------------
    source http://www05.abb.com/global/scot/scot281.nsf/veritydisplay/8bb8eedff9a70edec12579fe0052a2e3/$file/10th%20Qatar%20water%20gulf%20conference-ABB-Solar%20desalination.pdf 

    ------------------

    The selection of optimal solar-desalination-storage technology combination will require evaluation of each criteria as well as assignment of suitable weight for each of them to arrive at the preferred choice. § The weight assigned to each criterion will be governed by the priorities of the decision maker as well as external influencing factors such as local grid pricing, land pricing, environmental regulations, local laws, etc.



    PV vs CSP Solar Desalination§ PV plant located inland and providing electrical energy to the RO based-Grid connected desalination, will be a preferred option (due to higher DNI at the inland areas). § However, for CSP-MED combination, while less DNI and high land costs (at coast) are unfavorable, there are reduced costs due to waste heat utilization and use of the common power block. In addition to this, suitability of CSP based options for cheaper thermal storage over expensive battery storage will also be a favoring factor. § As far as operability of 24 hrs/day is considered, higher CapEx investment in desalination for urban municipal water applications, will require that these plants be operated at full load. This makes CSP options, with capability of thermal storage and integration with the conventional power plants, a preferred choice. § For low capacity rural applications, a standalone solar desalination system with relatively low CapEx will be suitable for the “day time only” operation. Cheaper hot water storage can be favorable for extending operational hours.§ Long term and high volume storage of water has limitations due to hygiene issues. In this case, thermal storage applications, although expensive, may offer possibilities of reduced water costs by ensuring full load operation (with/without conventional power plant connectivity).

    source http://www05.abb.com/global/scot/scot281.nsf/veritydisplay/8bb8eedff9a70edec12579fe0052a2e3/$file/10th%20Qatar%20water%20gulf%20conference-ABB-Solar%20desalination.pdf
















    Like

  • Nithya
    Nithya -

    A solar-​​powered solution to the worldwide water crisis

    The inno­v­a­tive device, dubbed the “Pyramid Desali­nator,” was designed for a senior cap­stone project under the direc­tion of mechan­ical and indus­trial engi­neering pro­fessor Mohammad Taslim. The under­grad­uate team mem­bers included Stephen Bethel, Dou­glas Dell’Accio, Matt Haf­fen­r­effer, Zach Modest and Michael Wegman, who con­ceived of the idea after com­pleting a Dia­logue of Civ­i­liza­tions pro­gram in fluid dynamics in Egypt.

    More than 800 mil­lion people throughout the world lack access to clean water, 3.6 mil­lion of which die every year from water­borne ill­nesses. “If we can decrease that number by even a small per­centage,” Haf­fen­r­effer said, “then our system can make a global impact.”

    The team’s desali­na­tion system con­sists of a one-​​square-​​meter alu­minum frame, a water tray and a water storage area located beneath the tray. A piece of plastic fash­ioned into the shape of a pyramid covers the entire contraption.

    Here’s how it works: A user pours a small jug of ocean water into the tray. The sun heats the water through the plastic cov­ering, causing the water to evap­o­rate. Wind con­denses the water, which then drips into the storage area. The salt in the water is left behind on the tray.

    The output goal is to pro­duce up to one gallon of potable water per day. Other desali­na­tion sys­tems on the market pro­duce a frac­tion of this quantity.

    Team mem­bers, who have already shipped a pro­to­type to Cameroon, a country in west Cen­tral Africa, hope to create a dis­tri­b­u­tion part­ner­ship with Water​.org or the Amer­ican Red Cross. source 

    http://www.northeastern.edu/news/2012/05/solardesalinator/ Like

  • Nithya
    Nithya -

    Suns River 

    Suns River uses highly innovative principles & processes to harness the power of the sun to distill a variety of inputs including but not limited to: seawater, river water, saline well water and waste water. It is simple to install & operate and does not require huge amounts of energy to produce 'fresh water'. The Suns River Solar Still has near zero carbon foot print.
    Ideal for India. Companies and Governments should get in touch with Suns River from India.


    The process is applicable to the coastal deserts of the Middle East, western Africa, the Indian sub-continent, Western Australia and Mexico. This is best summarised by saying that it can include any area that has a demand for a permanent source of pure water, a suitable water input and enough daily sunshine to power the Suns River Solar Still.
    In addition to simply providing pure water, we are confident that the SRL technology can and will spawn new economies in areas such as desert agriculture/ forestry and water exportation.Suns River - A New Patented Innovation
    Suns River brings forth a new, patented innovation in solar powered distillation with potential to become the low cost leader in desalination. The Suns River Still (SRS) multiplies classic still productivity by a factor of 5, operates on 95 – 100% renewable energy and has very low environmental impact. SRS has low sensitivity to higher salt concentrations. Thus feed streams can include water from the sea, rivers, saline wells and wastewater. With its product of pure, distilled water, Suns River can redefine the concept of hybridization of solar with existing desalination processes.
    http://suns-river.com/whatwedo.html 

    http://www.treehugger.com/solar-technology/looking-backward-move-forward-solar-stills-could-be-low-cost-leader-water-desalination.html 


    N.J. researchers devise means to extract twice as much potable water from seawater
    http://www.newsworks.org/index.php/local/item/38109



    Utility-scale PV for desalination. http://www.sunwindenergy.com/news/utility-scale-pv-desalination 







    SOLAR WATER PURIFIER & SOLAR DESALINATION TECHNOLOGY

    F CUBED is an Australian owned, global company, dedicated to the conservation, production and processing of the worlds most critical resource, water through solar desalination process & efficient water purification systems like solar water purifiers. Carocell solar desalinating / purification technology is the most efficient and cost effective system of its kind, producing pure, clean drinking water on any scale from any water source  http://www.fcubed.com.au/aspx/home.aspx.

    http://www.youtube.com/watch?v=iMbGGiqNIcc 

    Puduchery university seeks a tender for a solar desalination plant in pondichery India http://tenders.indiamart.com/details/615192716/


    Solar cucumbers - an innovative solution
    http://www.greenprophet.com/2012/04/solar-cucumbers-and-airdrop-irrigation-and-two-wet-and-wild-ideas/ 



    Qatar Increases Research on Using Solar to Create Water by solar desalination
    http://greengopost.com/qatar-solar-desalination-water/ 


    Small scale systems for solar thermal desalinationhttps://ssl.arcor-secure.de/case-m.de/doc/Aquasol.pdf














    Like

  • Nithya
    Nithya -

    a new seawater desalination process that uses less energy than conventional methods. Project engineer Riley McGivern,On a sun-soaked patch of gravel in Kakaako a small group of entrepreneurs are pioneering technology that uses solar energy to turn salt water into fresh water.
    The work being done by Renewable Water Technologies is early in the research and development process, but the company’s founders say it has the potential to be scaled up for commercial applications.
    Much of seawater desalination done in Hawaii and elsewhere is accomplished through reverse osmosis, a relatively energy-intensive process that removes the salt and other solids from water by forcing it through a membrane under high pressure.
    By comparison, RWT’s technology uses solar thermal collectors to heat the water and remove the salt through a humidification-dehumidification (HDH) process. The company’s pilot project features solar panels similar to those found in home rooftop water heating systems. The company is installing photovoltaic panels that will power the low-wattage pumps needed to move the water through the system.
    “It is designed to be modularized and deployable,” said John Chock, one of the company’s principals. “That’s the way the business will grow. Our business model is to produce small-scale, solar-powered desalination systems. more 



    *Spectra Watermakers

    Spectra Watermakers' patented energy recovery technology finally makes it possible to provide safe, pure water using solar power. Spectra Watermakers, Inc, is dedicated to seeking out, developing, and manufacturing technologies on the forefront of the desalination markets. Our systems use less than one third the power of a traditional desalination system by recovering the energy that normally goes down the drain. This proprietary energy recovery technology allows us to offer systems drawing as little as 8 Watt-hrs per gallon of water produced (2.1 Watt-hrs per liter), compared to over 30 Watt-hrs per gallon (8.06 Watt-hrs per liter) that the traditional systems our competitors build, the choice is clear.

    Both of our patented energy recovery pump designs were developed and are manufactured exclusively by Spectra Watermakers, we wrote the book on energy efficient, solar powered seawater desalination. No one can match the volume of pure, safe water production with the power required for our systems. Spectra's Research and Development team is working daily on moving desalination technology forward and leading the industry. Your project deserves the best. check it out at 



    Solar powered desalination in Middle East with brine evaporation

    A project between IBM Research and the King Abdulaziz City for Science and Technology in Saudi Arabia has been looking at commercial scale solar desalination for some time (see Water & Wastewater International story).

    Elsewhere in the Middle East, the Environment Agency Abu Dhabi (EAD) is more than two thirds of the way through a trial to construct 30 solar desalination plants across the Emirate.

    The pilot project launched in Umm Al Zamool aims to test solar desalination and each of the 22 plants built so far produces around 1,100 gallons of clean water per hour - approximately 6,600 gallons on an average day. Touted as “zero-carbon”, each unit generates an average of 35 kilowatts per hour, making a total of 1050 kilo-watt/hour.

    Each solar array measures 300 square metres at each site and this powers a pump that abstracts groundwater from a well. After a reverse osmosis membrane filtration, a subsurface irrigation system then pumps the clean water to a pond. The brine, or waste-water from the process, is pumped to a separate evaporation pond. source


    Concentrated Solar Power Salt Water Desalination PlantFresh water supplies are severely limited in many parts of the world, e.g., Central America, Gulf States of the US, Africa, Middle East, Southern Asia, Australia and Mediterranean Europe. Fortunately, they are close to large saltwater bodies with plenty of sunlight available year round. The sunlight can be utilized to desalinate saltwater to provide fresh water for drinking, sanitation and industry. Sustainable engineering is achieved by harmoniously utilizing nature’s abundant and free provisions (solar power, wind, sea water, etc.) in a way that is both beneficial for us humans and for the environment.

    In this setup, sunlight is concentrated, using mirror arrays that follow the sun (heliostats), and directed at a collector tank containing saltwater which is heated beyond boiling point, the steam is condensed in condensing tanks where the freshwater is stored before being pumped to other storage tanks for supplying to customers. There minerals can be added to enhance drinking water.

    This system can be setup on the sea on a platform that is floating or fixed at about 30m (100ft) of depth, or on land with the saltwater being pumped to the location. The condenser tanks are located about 30m below the water surface, where the water is very cool, or if on land they can be placed underground at about 10m depth with the soil providing insulation from the heat.

    For the same amount of energy supplied, saltwater evaporates faster than freshwater due to the former’s lower heat capacity. As the saltwater is heated beyond boiling point, the steam is directed downward to the condenser tanks. In another tank, superheated seawater is passed through an orifice or expansion valve, which produces steam that is also directed to the condenser. The remainder hot concentrated saltwater (brine) from this tank is used to store heat for heating seawater at night in a countercurrent heat exchanger, thus enabling desalination at night. Some of the hot brine is also used for producing sea salt.

    To lower costs, the mirrors can be flat (instead of parabolic) and the collector tanks can be made longer/wider to provide more collector surface area. The collector tank has glass side walls, glass domed roof and graphite/steel flooring and vertical graphite corrugated walls for added wetted surface area for heat transfer. The graphite may be backed with stainless steel for added strength. Graphite is a good conductor of heat, resistant to wear, environmentally friendly and its black color enhances heat absorption. Photovoltaic solar panels are used to generate electricity (with power conditioners and battery) to run the pumps, controls and other electrical equipment. Thus, this system can be made totally self-reliant with no external power required (except for back up diesel generator sets).more

    Like

  • Nithya
    Nithya -


    In the last 40 years the population doubled. Water requirement quadrapled !



    Yet the amount of water on Earth has stayed the same.

    Less than 1% of the water on planet blue is for humans to drink.

    About 2% is locked up in ice. The rest is for the fish.

    Desalinated water costs maybe 15 times more than regular water. It burns polluting fossil fuel energy, as solar-powered desalination is in its infancy.


    Infographic



    Like

  • Nithya
    Nithya -


    Economics of Solar desalination
    Environmental issues of solar desalination
    Experimental techniques for solar desalination
    ===================================================
    A solar desalination patent

    A solar desalination system includes a solar furnace for receiving seawater into a vessel and concentrating sunlight on the vessel to heat that water using solar energy to create desalinated steam. Water is input into the furnace via a pump that is powered by a reciprocating solar engine. The reciprocating solar engine includes a seesawing platform with a closed system of two or more connected containers thereon. Solar heating causes a fluid to move from one container to another causing the platform to reciprocally rotate through a predetermined arc, creating energy that can be harnessed. A riser pipe extending upwardly from the solar furnace carries steam to an electric power-producing steam turbine generator where the steam generates electricity. A drop pipe extending downwardly from the steam turbine generator carries desalinated water to an electric power-producing hydroturbine generator where the water generates electricity and is then removed for subsequent use.more
    =====================================================

    "Desalination involves the removal of dissolved salts from water. The minimum energy needed for desalination is 0.8 kWh/m3 for seawater at 25 degrees Celsius. This is the theoretical minimum.

    Taking into account inefficiencies of various components, it will require more than three to five times that energy in real world conditions," 

    =============================================================

    Like

  • aathmika
    aathmika -

    A solar desalination patent

    A system for creating desalinated water from seawater and also creating electricity includes a solar furnace unit. This furnace unit includes a vessel for receiving and evaporating seawater which is heated by a solar energy concentrator. Seawater can be input into the vessel and brine can be removed from the vessel. A riser pipe for steam extends upward from the vessel to a higher-elevation steam turbine generator. A drop pipe for draining desalinated water extends downward from the steam turbine generator to a hydroturbine generator. Desalinated water generates electricity as it moves through the hydroturbine generator. The desalinated water can then be subsequently used. The input for feeding seawater to the vessel includes one or more pumps that are powered from a solar-initiated wind power generating system.

    InventorKenneth P. GLYNN
    Current U.S. Classification202/189 source

    Feasibility of Small scale Solar Powered RO Desalination Like

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