Har Ghar Solar: Grid Connected

We all understand the benefits of solar energy. Currently, it is the hot topic among residential sector. And why not? With reducing price of Solar system and constant support from government on form of subsidies, it is great time to invest on SOLAR and enjoy butter for next 25 years.

Tea is best prepared when one knows about the quantity of ingredients to be added. So, the question is HOW MUCH? How much capacity of solar system can you install in your premise. In the current blog, we will be talking about grid connected Solar PV system. The capacity of system is dependent on the load of the consumer. In simpler words, it is dependent on how much appliances one use during the day.

In the below example, we have considered a typical 2 BHK house with basic electrical appliances.

Let’s assume that the below chart represents consumption of a house in a day;

Equipment	Quantity	Power Consumption (W)	No. of Hours	Total consumption (Wh)
Fan	3	50	6	900
Tube light	3	35	6	630
CFL	3	12	8	288
AC	1	1200	4	4800
Washing Machine	1	750	0.5	375
Refrigerator	1	150	10	1500
Miscellaneous	1	200	1	200
Total Consumption				8693
Margin@10%				869.3
Total Consumption in kWh				9.56

A typical solar system with capacity of 1 kWp generates 3.5-4 kWh. The solar calculator by NREL; PVWatt gives consumer an idea about the annual generation by solar PV system.  Considering the same, a solar system of 2-2.5 kWp would be sufficient for the above table. One need to consider peak consumption during the day.

A better and accurate method to calculate the load would be an electricity bill. Analyse the electricity bill to find monthly consumption & daily peak consumption and accordingly install the PV system.

Apart from the consumption of the house there are some other factors which has to be considered while determining capacity of the system, such as:

Sanctioned Load

This can be determine by going through the electricity bill. Government allows only a percentage of total sanctioned load to be capacity of system. Kindly refer the solar state policy to know the allowed percentage.

Shadow Free Area

One of the key factor when it comes to installing solar system is shadow free area. Shading on single module affects the performance of whole string by increasing shading loss. Hence it is important to identify area without obstacle before installation. To install 1 kWp of system, approx. 100-125 sq.ft. is needed.

  

     Orientation of House

This is one factor which is not in your control. There are scenario where the house/ flat are not facing true south. In such cases, it is advised to change the orientation of the system to true south to achieve maximum output. This would definitely reduce the capacity of the system which you could have installed in orientation of house.