Integrating Rooftop Solar with Diesel Generator for Diesel Reduction - India Renewable Energy Consulting – Solar, Biomass, Wind, Cleantech
Select Page


Are you looking to get energy security for your company through reduction in the use of diesel, furnace oil, LPG and costly grid power?

EAI can do a feasibility study for the use of solar PV & thermal, biomass for heat and power, waste heat recovery and energy efficiency to dramatically cut down fossil fuel use and reduce your energy bills. See EAI’s SURE-FIRE offering for more.


 Issues to be considered while integrating rooftop solar power with diesel genset power

A question asked by many interested in using rooftop solar for diesel abatement is: how well can rooftop solar power integrate with diesel power if both are to be used simultaneously?

This question is especially relevant because the most productive use of solar power happens during load shedding, when companies have to use costly power from diesel gensets. The more solar is able to reduce the extent of diesel genset use, the better the economics.

There are several issues to be considered while integrating solar power into the diesel genset power generation system. These have to do with the fact that solar power is intermittent, as well as the fact that diesel gensets need to operate at certain minimum load factors for them to run with high efficiency.

This blog post provides insights on the key issues to be considered while integrating rooftop solar with diesel gensets.

Part of the content for this post was derived from Solar Mango – the Rooftop Solar resource.

Some of the critical challenges to be considered while integrating rooftop solar with diesel gensets are:

Frequency & Power Quality: As the loading factor of the diesel generator varies (as a result of introducing an intermittent solar power source into the mix), the frequency of the output AC power can vary beyond acceptable levels reducing the quality of power. Some modern devices require high quality power to operate

Reverse Current Flow: When the output of the solar power exceeds the load demand, some reverse current will flow into the diesel generator. There are acceptable levels to which this can happen beyond which the diesel generator trips, terminating the reference voltage for the solar system causing it to shut down

Efficiency and Minimum Loading: Diesel generators operate in various modes. Running a generator at loads below the minimum load factor for prolonged periods affects the efficiency of operations which in turn has a bearing on fuel consumption, maintenance costs, and useful life. Operating below the minimum load is possible if a sizable solar system is integrated into the supply and results in decreased lifecycle savings of the solar-diesel generator system. This should be specially considered by those who have only one diesel generator, or use only one diesel generator at a time, as the generator’s load will reduce once solar is introduced. In a multi-generator system, it is possible to balance the load by turning off some generators completely, and running the other generators at full load and optimum efficiency.

Overall, it can be said that plugging a solar power system into the diesel genset backup system might force some compromises as well as sacrifices in efficiency that might creep into the genset operations as a result of the inclusion of the SPV system.  It can however be expected that these compromises and losses in efficiency will decrease as the solar and diesel genset industry starts collaborating with each other. Already in India, many diesel genset makers are keen to provide solar power solutions to their clients; thus, one can expect innovations to happen fast in this sector.

Further data on these are awaited from various installations running diesel/solar, as the use of large scale solar power to offset diesel consumption is a fairly recent activity (only starting 2013), and thus there is little analysis or understanding of all the complexities even for industry veterans.

EAI’s Diesel to Solar Report – The one and only such report in the world

EAI has published a unique report to assist those keen on using solar power to offset their diesel consumption.

To know more about integrating rooftop solar with diesel gensets, you can also refer to this comprehensive report EAI has published. The Diesel to Solar report is a comprehensive guide to implementing a rooftop solar system to reduce diesel consumption for power.

Related posts for replacing diesel with solar

Substituting Diesel with Rooftop Solar PV – Economics and Costs

Rooftop Solar – Solutions to Support Different Loads While Offsetting Diesel Consumption

Can Rooftop Solar Power Replace All Diesel Consumption from Gensets?

Diesel Reduction Using Rooftop Solar Power – Constraints and Considerations

Replacing Diesel Gensets with Solar on Rooftops – Something Really Worth Exploring for Indian Industry

Also: Check out an interesting site on solar: Suncyclopedia, the Solar Encyclopedia

About Narasimhan Santhanam (Narsi)

Narsi, a Director at EAI, Co-founded one of India's first climate tech consulting firm in 2008.

Since then, he has assisted over 250 Indian and International firms, across many climate tech domain Solar, Bio-energy, Green hydrogen, E-Mobility, Green Chemicals.

Narsi works closely with senior and top management corporates and helps then devise strategy and go-to-market plans to benefit from the fast growing Indian Climate tech market.

Know More...Connect with our director

Copyright © 2024 EAI. All rights reserved.