With around 300 sunny days every year, India has great potential to harness sun power, says SATHYA PRAKASH VARANASHI

Which is the single source of power available virtually everywhere and will never exhaust? Not everyone may get the answer right, but majority may guess it to be the power from the sun. Which source of power can we name for being plentiful, green, clean and free? Now everyone will get it right – solar power.

At present all of us get the image of water heaters when we mention solar, which technically is termed solar thermal, while solar photovoltaic power is a different approach. In the former, heat in solar radiation is directly transferred to water by direct exposure, which is a simple technology, quite like boiling water on fire. Photovoltaic technology, simply called PV, directly produces electricity from light, with no material waste, moving parts, maintenance and such others, hence is among the best non-polluting sources we have today. With an average 300 sunny days an year, India has great potential to harness sun power.

Solar power need not be transmitted across long distances, can be localised within our building sites and is possibly the most sustainable power for ever. It is basically DC current, so during the early days a separate wiring circuit was done with special DC bulbs fixed to utilise the generated power. With improved technology nowadays, solar power is directly converted into AC current, same as the type supplied by State electricity grids.

Of course, we need inverters and separate UPS systems, which get charged by solar during daytime and by the State grid during night, for further connection to the whole house through the main distribution board. The rapid fall in rooftop solar power generation has made the technology affordable for increased number of families today.

Problems

For argument sake, solar power is also not without its set of problems. Installing the solar panels requires surface areas up to 100 sq. ft for 1 Kw; periodic disposal of storage batteries with toxic components is hazardous and cloud cover drastically reduces power generation, demanding a back-up. However, solar scores more on many other fronts compared to hydro, coal, bio-mass, wind, nuclear and such other sources of power.