When the rays of the sun fall on solar modules placed on the rooftop of houses, commercial building or industries, the individual cells inside the module help convert sunlight into DC electricity. However, most appliances in our homework on AC electricity, and therefore the modules are connected to an inverter which does this conversion. Once the conversion has happened, the output of the inverter which is AC electricity is connected to the mains of your home to allow you to use solar energy.
It is important to note that you can use electricity from your rooftop solar power plant in conjunction with the electricity sourced from your MSEB. This kind of arrangement is very common and one that solar installers are expert at managing. However, if you want to go with a system that is backed by a battery to help you use solar at night time, you must go for a hybrid or an off-grid system. What exactly is that? That brings us to the next section, which is what are the different kinds of solar systems that you can opt for:
Types of solar systems:
Grid-connected systems or on-grid systems, are solar systems that are connected to the building mains directly. These systems give priority to the solar power generated and only if the generated power is less than that required, will the grid power be used. As explained above, inverters are used to convert the produced DC electricity to AC. In case you opt for a grid-connected system, you are eligible for Net Metering, a process where all the excess power that you produced is fed back to the grid and you receive a credit for the same. In case you generate more than you consume in one complete year, the MSEB also pays you for the excess units generated. In many states, Net Metering has been made mandatory to avail subsidy for solar.
Off-grid solar systems are different from the on-grid system in the sense that they are set up independently from the state grid. These systems have an additional battery backup system which is charged by the generated solar energy. Batteries are charged when the generated power is more than the power being consumed. While on paper, battery-backed systems sound like a great idea, these systems are generally more costly than on-grid systems and have lower efficiency. The battery needs to be replaced every five years or so but on the positive side, you can use solar energy even in the hours where there is no generation. Off-grid systems are perfect for your rooftop solar plants if you have a very erratic power supply or do not get any power at all.
A hybrid system brings the best of both worlds and is a combination of an on-grid and off-grid solar system. Hybrid systems have a battery backup which helps store the generated energy. What differentiates hybrid systems from off-grid systems is that, once the battery is fully charged, any excess power generated which is not being utilized will be fed back to the grid and you will get suitably compensated. A hybrid system can also have other sources of energy producers, such as Diesel Generator (DG) or Wind coupled in the system.
Can I install rooftop solar?
The short answer to the question is that as long as you have a rooftop, there is nobody who can stop you from installing a rooftop solar system. Even if you are living in a high rise, you should check up with your RWA as societies today tend to have shared rooftops where there is a provision. However, there are some obvious things to consider before you decide to install rooftop solar on your house:
Area: First thing you must check is whether you have enough clear area to install solar panels. Also, the area should be enough to house the panels that are recommended for the system that is adequate to meet your demands.
Consumption: Solar power is a boon for high consumption residents, industries and commercial properties. Due to the saving, you make on your electricity bill, higher your electricity, the more beneficial going solar is in general. Let’s try and explain this with an example. We ran the GREENLIFE Basic Calculator for two residents living in South Extension in New Delhi. One with electricity bill amount Rs 1000 and the other with bill amount Rs 10,000. We found that the customer with the bill amount of Rs 1000 saves about Rs 153 on his electricity bill while the resident will bill Rs 10,000 saves Rs 2,162 with a return of more than 27%. It is also worth noting that system that is smaller in size are more difficult to obtain and do not give high financial returns.
Policy: Most of the states in India have a dedicated rooftop solar policy. If you are unsure or have not read about the same for your state, you can read it here. Several states have made Net Metering mandatory as well as offered some really lucrative schemes for you to install a rooftop solar PV plant. Make sure you are well aware of the policy in your state and stay up to date with the same.
Net Metering: Just like the solar policy, Net Metering policies differ from state to state. Some MSEBs are faster in processing the applications whereas some are slower. It would not be a bad idea to speak to your MSEB or solar installer regarding Net metering before you decide to go solar. You can also get in touch with our expert solar advisors by clicking here.
Approvals: Installing rooftop solar PV plant may require an approval or NOC from your MSEB depending upon the type and size of your solar system. Also, some states including Delhi have a more relaxed approach to approvals. It is no doubt that in states like these, installing rooftop solar is a much faster process. If you live in a society of flats, you may need approvals from your RWA, so you should check up on that too.
Shading: If your rooftop is heavily shaded by nearby objects, it may prove to be not the most ideal place for installation of solar panels. If you have a lot of shading on your rooftop, there are some alternatives that the Engineering & Design team can offer, but there is no universal solution to the same. Therefore you must keep a close eye on the shading. GREENLIFE specializes in providing advanced shading analysis tools and site assessment services.
With the GREENLIFE Advanced Rooftop Solar Calculator, you can factor in virtually all of the above at one place and very easily find your solarisation potential. Not just that, but with the Advanced Calculator, you can also understand and avail the different financial options available to you and make a choice whether to buy the solar system and all its parts or just buy solar power.