Rooftop solar installations are good for Chennai

Tamil Nadu already is a leader within India in terms of alternate energy. Apart from setting up plants for generation of electricity from agricultural waste, the state is also a leader in harnessing wind energy. The initiative to encourage setting up roof top photovoltaic is therefore a very logical extension of the State’s policies. 

Apart from generating energy in a “green” way the thrust towards distributed solar installation would encourage small medium enterprises and also generate employment for technicians.

Chennai has many natural advantages when it comes to tapping the potential of solar energy. It is situated in the low latitudes because of which there is less variation in the amount of sunlight it receives during the entire year. It is also relatively dust free compared to cities like Delhi. 

The intensity of solar radiation and the number of hours of exposure are so favourable that in Chennai a solar Installation of 1 KW capacity can produce 2,000 to 2,200 units of electricity in a year. A comparable set up in Germany for instance, would yield only about 1,200 units. In Chennai, at the current rates, this is about Rs. 10,000 an year of electricity. A grid connected solar investment in Chennai, after subsidies, is expected to cost between Rs 60,000 and 80,000. The investment is therefore recovered in 6 to 8 years, with no consideration for inflation or increase in power tariffs. Considering that a solar installation is expected to have a minimum life of 25 years, this is truly an investment the next generation would thank us for. 

Solar installations can be centralised, with large capacities or be distributed with small capacities. The distributed solar installation has the advantage that the power is generated close to the point of use, thereby reducing transmission losses. This is a win-win situation for all the involved parties, as waste benefits no one. 

Solar installations in the US have tended to be centralised or distributed depending on the specific States’ policies and the National average is 35 per cent distributed. In Germany 65 per cent of solar installations (in terms of capacity) are distributed installations. 

Rooftop solar is very appropriate for a city like Chennai where land is quite expensive. Roof top solar does not require any additional land. 1 KW capacity can be set up in about 50 to 60 sq ft of roof area.

Installation should be executed as per building codes to ensure that it can withstand the prevailing winds and the seasonal strong winds. The basic wind speed to be considered for Chennai is 50 M/ sec which would ensure that the structure is stable even under cyclonic conditions. 

Care should be taken to ensure that no shadow falls on the installation to get the maximum benefit from the investment. 

Given all these advantages and the favourable economics one can be sure of the long term success of this initiative. The momentum is building up and in the coming years there is bound to be a great potential.