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  • Animesh Manek

5 things to know before you go solar

We've been hearing about #solarenergy and its great benefits—not only does it save your money spent on paying huge electricity bills but also does a lot of good for the environment. The fact that you can use your own rooftop to install #solarpanels that would provide 25 years of free electricity seems fairly easy. Then what's stopping most of us from opting for it?

The answer—not enough knowledge and a lot of misinformation. Most of the people think rooftop solar is extremely costly. But rarely do people notice that all of your investment gets returned in 3-4 years after which you're practically using electricity for free.

Similarly, a lot of people feel that a #solarPV plant might need a lot of maintenance. But the rooftop solar plants installed in the cities are usually on grid. Which means, there isn't any battery used. The only maintenance it needs is regular cleaning that you can do yourself. There are a lot of myths surrounding the rooftop solar concepts and to ensure that you're starting your rooftop journey on the right foot, make sure you get your basics right in the first place. To go about it the right way, ensure you are not getting misled by wrong information, baseless promises, and scattered answers. When you sit down to plan your rooftop solar journey, jot down these points to discuss with the vendor. The right vendor will not only guide you with all the information you need but also help you navigate through the process as smoothly as possible.

So here are the 5 things you need to know before you plan solar.

The difference between on-grid and off-grid system.

On grid rooftop solar plant runs on net metering policy. The concept is simple - your house is already connected to the grid from where you get your electricity which is called units you import from the grid. Once you install the rooftop solar PV system, it provides you electricity too - these are the units you will export to the grid. On high generation days, a lot of units get sent to the grid - may be even more than you need. On these days, you will not be importing anything from the grid, in fact will be sending additional units to it. On low generation days, fewer units get exported and the remaining required units will be taken from the grid. At the end of the month, your electricity bill is calculated like this:

Units exported – Units imported = Units consumed

Sunlight received at your location across 12 months of the year.

Your rooftop solar plant's performance is calculated yearly. If you have enough roof space to install the required number of #solarpanels, you can achieve up to 100% savings on electricity bills annually. Which means your rooftop #solarPV plant is designed keeping the generation for all the months in mind. Monsoons will show low generation, winters might be foggy and hence less generation, bright sunny days will have more. You need to now these details in mind and then ask about the annual units generation as promised by the vendor. Your rooftop solar plant will perform as per the sunlight received. If you're looking for some kind of a generation guarantee, you can always opt for installing a device called pyrano meter which notes the sunlight received against which the generation is measured and the performance is calculated. If you don't want to add the cost for the device, having a detailed calculation about how the promised generation is calculated across the months will be helpful. At Avishakti Solar, we have our proprietary database that gives the sunlight and generation numbers from the past 8 years. Therefore our designs are as per the latest numbers and quite reliable. The other database used by vendors in general have become a little obsolete and come with an error margin.

Area available on the roof and how much of it is shadow free.

Did you know that if a solar panel is installed at a location where there is a lot of shadow, it can get burnt or become dysfunctional? Have you noticed vendors coming for a site visit simply standing on the roof, and randomly coming up with a number of panels that can be installed - simply by looking at the area? Here's the catch. No roof is the same as any other roof in the city like Mumbai or for that matter any city in India. There are structures like water tank or pillars or buildings around the roof. There are shadows being cast by trees along side the periphery. How do we know how many solar panels can be installed unless a thorough site visit is done and shadow free area is calculated?

When you're talking to the vendor, ensure you are asking for the 3D model and shadow analysis about the roof plan. You must know how much shadow is cast on the roof for the whole area across the 12 months to get the most optimized design. A random number basis just the area in sight can cause severe generation loss and hence make your #rooftopsolar plant a non feasible option for you in the long run.

Wind speed experienced in your area and your structure's stability requirement.

The solar panels are installed on a structure that gives them a stable, strong base to stand on. Most of the times, the structure's stability gets questionable. While the focus is always on the quality of solar panels or the invertor, people forget how important a role the structure plays in ensuring longevity of your rooftop solar plant. Not only does the quality matter, the structure's design also must be in line with the integrity standards. For someone who won't know enough about this - can end up getting a bad deal. Because people don't focus on structure, a lot of time the vendors end up compromising on the quality in its components. Getting a poor quality or a badly designed structure can be serious trouble. Your solar plant can get damaged in cyclones or heavy winds. Its integrity can give in over time and you might have to redo the whole system again. The repercussions can be huge. It's better to get the quality right from the beginning and to be on the safer side, get a vendor that offers a structural integrity certificate from a structural engineer.

Subsidy and financing schemes applicable and available to you as per your location.

There are several subsidy schemes run by central and state governments for encouraging people to opt for solar. However, not every rooftop solar plant is eligible for subsidy schemes. Most of the times these schemes are time bound, and other times, they are applicable to only a certain type of solar plant. Make sure you have a candid conversation with your vendor on the same. For example, your plant might be eligible for subsidy from government on a condition that you only use a certain brand of solar modules. Now, this brand might offer only up to 300 kWp modules due to which your plant capacity would be quite low compared to when you use 500 kWp modules that are available from non subsidized brands. At this point, note down the loss that you'd be incurring by going for a lower capacity plant over 25 years - vis a vis the one time subsidy amount you'd receive. There are times when it might be worth going for subsidy, but there are other times when it simply won't be worth the effort.

To know more about how you can optimize your rooftop solar project, get in touch with our team at

Loved the insights shared? Download a handy guide on 5 things to remember when you go solar here.

5 things to know before you go solar
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