5 Most Common Queries on Home Solar Rooftop Solutions Answered

A solar rooftop system is an easy-to-install system that is almost always connected to the power grid in India. It is the most reliable green energy form while saving on electricity charges. With a lifespan of 25 years, it uses existing rooftop space and saves on land space. Going solar has helped several home owners save their money while letting the sun power their homes.

The on-grid rooftop system comprises of a series of solar panels which are mounted on the roof and connected together. They convert solar radiation to electrical energy. The electrical energy from the panels goes into an inverter which then gets converted into alternating current compatible with grid power.

As a home owner, here are the top five most common queries on solar rooftop systems that will help you quickly decide on the best solution.

How much space do I need? I live in an apartment; can the solar rooftop system be installed in my balcony?

Rooftop solar PV systems generally require 100 sq. ft clean shadow free area per KW to install and work. This means that a 25 KW system will require about 2500 sq. ft of clean shadow free rooftop area. An apartment balcony cannot support the solar system, and is not a feasible option. The best solution here is when apartment owners association get together to use the common terraces for solar systems, that can then power common facilities.

How many KW system would I require for my house? How many units of electricity will be generated from the solar PV system?

The size of the solar system would largely depend on your electricity bill. You would require a 1 KW system for a bill of Rs. 800-900. A 1 KW system usually generates 4 units of electricity per day, or close to 1200 units per annum.

What kind of module should I opt for – polycrystalline or monocrystalline?

The myriad product can make it hard to arrive at a decision on which kind of module to opt for. Modules are made of solar cells. Monocrystalline solar panels have solar cells made from a single crystal of silicon, while polycrystalline solar panels have solar cells made from many silicon fragments melted together. These are known as mono or poly for short. Mono panels are known for better performance and aesthetics, while poly panels are better suited for budget-conscious consumers due to their lower cost. Poly modules are also more resilient. Presently, most subsidy supported schemes across Indian states will provide you poly modules. However, if you take a non-subsidy route, you will have a wider choice of modules to pick from.

How much money can I save if I install a solar rooftop system?

A solar system has a return of investment of about 25-30% means for every lakh invested, the earnings are about Rs.25,000 – 30,000 per annum. An on-grid solar system connected to a net-metering installation ensures you get credit for any additional power generated on sunny days.

If the initial investment is not affordable, what are the financing options?

Both the Central Government as well as State Nodal Agencies (SNAs) offer subsidy schemes for installing rooftop PV systems regularly to improve affordability. Up to 3 KW, subsidy offered is 40% and above 3 KW and up to 10 KW it is 20%. These schemes also mandate specific conditions for installers, from maintainance to quality control on all equipment used and its testing.

Loans are also available to fund the initial investment in a solar plant today at a rate of interest usually between 8.5-9%. The earnings from the system are for more than 25 years.

You must also pay attention to the quality of modules, and opt for branded ones. While both branded and local modules initially show the same performance, with degradation, you will find that reputed quality solar panels provide better output and are more efficient. Choose a good installer to help you fix the panels. Don’t cut corners as the installation will also make a difference in extracting maximum benefits from your solar system.

Besides this, people wonder if solar systems will function during a power breakdown. As we pointed out, a grid connected system won’t. For that, you will need an off grid solar system with storage. This option is not yet viable financially for households, although it is increasingly finding wide usage in commercial and critical applications.

Inputs from Goldi Solar