What size of solar inverter/PCU should I choose?

In On-Grid Solar Plant the solar inverter serves as a DC to AC converter which then sends the current in the connected line. It is recommended that the size of the inverter in on-grid installation should be equal to the total power of the solar panels. For eg. if you are installing solar panels of 3kWp, then the solar inverter should be of 3kW.

In Off-Grid Solar Plant the solar PCU is a standalone unit that serves as an inverter and has an inbuilt solar charge controller. It is recommended that the size of the inverter in the off-grid installation should be at least 40% more than the total power of solar panels. So if you are installing solar panels of 3kWp, then your solar inverter should be 4.2Kva.

How to Calculate the Size and Capacity of Battery?

You need batteries to store the extra solar energy you generate which can be used later (in the absence of Sun). The size of the battery depends on the energy usage during backup time that you would draw from the batteries. Battery capacity should be at least 160% of the energy consumption. Let’s say that your total load is 1500Wh.

So you need minimum of 1500×160% = 2400 Wh capacity. Means 12V/200Ah or 24V/100Ah battery.

It is advised to select the capacity of battery approximately 1.25 times of the above calculation for reliable operation.

In the above-mentioned example, you can use 2 nos. 12V/120Ah solar batteries.

Which system should I chose  On-Grid/Off-Grid solar system?

If your location doesn't have many power cuts and you want to trade electricity with the electricity department you should go for On-Grid Solar Plant. But If your location has power cuts and you want backup then you should go for Off-Grid Solar Plant.

How much rooftop space do I need for solar?

Most of the solar panels are installed on the rooftop. However, in some cases they can also be mounted on ground. You would need a shadow-free area of approx. 100 sq.ft. to accommodate 1kWp solar panels. Please make sure that the area gets maximum sunlight. We will select the best angle for the solar panels.

For how long will I be able to run my connected appliance on solar? How much electricity will it generate?

An off-grid 1KWp solar system can provide an average of 3.5 units electricity per day. While a grid-tie/on-grid system can provide an average of 4 units per day.

How do I calculate solar savings?

Most of the time, the number 1 reason for installation solar at home in India is to save money– fair enough. Going solar really helps people who usually get very high electricity bills because they get to make their own electricity for free. Let’s say that you have a 5kW system, then it will generate 20 units of electricity per day – 600 per month – 7200 per year. If 1 unit of electricity costs Rs. 9 then it would cost Rs. 64,800. You would make Rs. 64,800 worth of electricity through solar – this is your savings.

Can I get the subsidy from the Govt if I install solar?

Yes, some states in India do have subsidy schemes and some offer to buy the extra solar electricity that you make (through grid-tie systems). However, in reality, very few people are able to avail of subsidy because it requires too much paperwork and too much time. Our advice would be to forget about subsidies and select a solar system that gives you a good ROI. We have seen that some people recover the cost of installation in just 4 years!

After I install the solar system do I need to worry about maintenance and service?

Solar panels are quite rough and tough and come with a warranty of 25 years. However, with time the solar power system (panels, inverter and battery) may get some technical problems. So it is very important that you buy your solar system from a reputed vendor who offers good service as well. We discourage you from buying cheap solar products because they are very unreliable. When you are installing solar, think of it as an investment. A good investment will bring great returns. Always go with a reliable vendor.

Does the Solar Plant work even in rainy or cloudy weather?

Yes, Solar Panels are made up of photo cells which convert the day/sun light into electricity so more the intensity of light more will be the electricity generation. So, even in cloudy or rainy weather the solar plant will generate electricity but it won't generate electricity at night. 

©2020 by C.P. Solar Energy.