Que: What parameters should a corporate entity study before going in for a rooftop solar plant?

Ans: 1. Strength of the Roof to bear the load of a solar power plant – industry standard requires a distributed load of about 25 kg/sq. m and a point load of 80 kg/sq. m

2. Shadow-free roof area available – thumb rule is about 10 sq. m/kWp. Shadows caused by overhanging wires, fences, etc. drastically impact the generation and life of the modules.

3.Roof orientation – Solar plants are most efficient when the panels face south and are tilted at an angle equal to the latitude of the location. On RCC roofs, mounting structures are erected keeping this mind, but on tin sheds, the plants are installed according to the roof orientation. For RCC roofs, we also factor in aspects like shadows caused due to water tanks, lift motor roofs, parapets, etc. while prescribing the project design

4. Weather conditions – Solar plants are efficient in areas that see a lot of bright sunshine for most of the year. In India, western and southern regions receive maximum sunshine.

5. Energy consumption pattern – Energy produced should be consumed immediately or exported to the grid. Storage projects are still not economically viable at a rooftop scale. Solar energy production happens only during sunlight hours, with about two- thirds of the production between 10 am -2 pm. So consumers who have major night time load or which are shut down during the morning hours, lunch hours, holidays, vacations, etc. should evaluate whether they will get full net meter benefits to be able to export the products to the grid during production hours and draw it back during consumption hours. Therefore, it is imperative for state governments looking to enhance their renewable capacity to consider tweaking net metering benefits to incentivize consumption of clean power. Many states in India do not allow net metering or have a limited settlement cycle like one month. There is also a cap on the size of net-metered projects – usually 1 MWp-2 MWp.

6. Investment model – Solar plants can be installed on various investment models like CAPEX, OPEX or EMI depending on the tax benefits, cost of debt and cash-flow considerations.

7. Availability of water – Solar panels need to be cleaned every 1-2 weeks with clean water. At an average, each cleaning consumes about 5-10 liters / kWp

8. Reliability of the grid – Solar power plants are grid-connected and work only when the reference voltage from the grid is available. In cases where there are frequent grid outages, the plant does not operate for such hours. It can be operated through reference voltage from a diesel Genset, but generally with some curtailment as the diesel Genset needs to be operated at a minimum load of 30%.

Que: How can a corporate entity identify a solar installer for its rooftop project?

Ans: Assess the space available. Depending on the size of the plant identify the top 4-5 players who operate in that size segment. It is an investment for 25 years and the quality of the installation, as well as its upkeep, is very important. One should only opt for reputed players who are expected to remain in business for that long. At Fourth Partner Energy, we cater to over 100 corporate clients and have an operational capacity of 200+ MW. Our projects range from capacities of 500 kWp to 22 MWp.

Que: Should a corporate entity look at buying the modules on their own and get the installation done by a solar company?

Ans: Its best to give out a turnkey contract to solar players since solar players can get the best pricing and select the optimum modules, inverters, and balance of plant. Many plants fail because the equipment is not compatible. At Fourth Partner Energy, we offer end-to-end services right from site survey to design, innovative finance, project installation and Operations & Maintenance services for the lifetime of the solar installation.

Que: How does one ensure the maintenance and low-cost operation of a rooftop solar plant over 25 years?

Ans: •Careful designing. The plant should be designed to optimize productivity – cramming capacities does not help.
•Good quality equipment and structural materials
•Good quality installation by experienced engineers
•Regular monitoring and timely rectification of faults
•Regular cleaning
•Regular preventive maintenance
•Adequate security
•Focus on maximum savings rather than minimizing costs. The output of the plant falls exponentially if not maintained well.

Ensuring maximized generation and plat uptime is an assurance we give with all seriousness at Fourth Partner Energy – our dedicated in-house O&M team is tasked with ensuring the same.