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Key factors to consider while setting up a solar plant

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The following are the important key factors to be considered before setting up a solar captive power plant:

1. Load Supported

They are usually the largest single influence on the size and cost of a PV system. A PV system designer can minimize a PV system’s cost by efficiently using the energy available. The first step is to estimate the average daily power demand of each load to be use. It is important to note that one should be thorough, but realistic, when estimating the load. A 25 percent safety factor can cost a great deal of money.

2. Type of Loads

While estimating the load, it is necessary to calculate for both ac and dc loads.

3.  Hours of Operation

An hour of operation is an important factor. This value helps us determine the exact consumption of electricity (kWh) of each appliance. Calculating this value will help the designer in the first level assessment of the size of the solar system that will be needed to power the site under consideration. More importantly the time of operation during the day will enable a designer to do a more accurate sizing of the PV system. For example, a refrigerator runs for 24 hours in a day. Other appliances like washing machine will run 2 hours a day in the afternoon. So a PV system can be designed to supplement grid electricity by providing electricity during peak hours. It is also possible, if the user wishes, to design a complete solar system to provide electricity throughout the day with battery backup.

4. Days of Autonomy

Autonomy refers to the number of days a battery system will provide a given load without being recharged by the PV array or another source. General weather conditions determine the number of “no sun” days which is a significant variable in determining the autonomy. Local weather patterns and microclimates must also be considered. Cross-check weather sources because errors in solar resource estimates can cause disappointing system performance.

The most important factors in determining an appropriate autonomy for a system are the size and type of loads that the system services. The general range of autonomy is as follows.

  • 2-3 days for non-essential uses or systems with a generator back up
  • 5-7 days for critical loads with no other power source

 5. Space Available

For setting up 1 kW SPV system without batteries, the required shade free area is 100 sqft.

Knowing the installation site before designing the system is recommended for good planning of component placement, wire runs, shading, and terrain peculiarities. The primary requirement in selecting the space is that, it should be shade free. Shading critically affects a PC array’s performance. Even a small amount of shade on a PV panel can reduce its performance significantly. For this reason, minimizing shading is much more important in PV system design. Carefully determining solar access or shade-free location is fundamental to cost effective PV performance. . When a site is selected, be sure that the following parameters are met and tasks completed.

  • Be sure that the array is not shaded from 9 A.M to 3 P.M.
  • Identify the obstacles, if any, that shade the array between 9 A.M and 3 P.M
  • Make recommendations to eliminate any shading, move the array to avoid shading, or increase the array size to offset losses due to shading.

Other factors to be considered

  • Keep it simple - Complexity lowers reliability and increases maintenance cost.
  • Understand system availability - Achieving 99+ percent availability with any energy system is expensive.
  • Know what hardware is available at what cost - Tradeoffs are inevitable. The more you know about hardware, the better decisions you can make. Shop for bargains, talk to dealers, ask questions.
  • Install the system carefully - Make each connection as if it had to last 30 years-- it does. Use the right tools and technique. The system reliability is no higher than its weakest connection.
  • Safety first and last - Don’t take shortcuts that might endanger life or property.
  • Comply with local and national building and electrical codes.
  • Plan periodic maintenance - PV systems have an enviable record for unattended operation, but no system works forever without some care.
  • Calculate the life-cycle cost (LCC) to compare PV systems to alternatives – LCC reflects the complete cost of owning and operating any energy system.

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