Igniting a solar revolution

It goes without saying that India has been endowed with an inexhaustible source of solar energy. She has 300 clear sky days in a year. The intensity of solar radiation available over the Thar desert in Rajasthan is maximum in the world. Daily temperatures vary between 35 to 45-degree centigrade for eight months of the year around midday. Still, the exploitation of solar energy for three different uses i.e., heating, cooking and power generation, has been very slow over the years. The reason for this delay is ignorance of the government about the immense uses of developing solar energy.

Till now, the focus of the Central government has been entirely on developing solar power neglecting the other two equally important uses completely. Even then, the total power developed so far has been 35,000 MW only against the target of one lakh MW by 2022. How the target of remaining 65,000 MW of power will be met in the next two years is anybody's guess. It may be clarified that one MW solar power plant will generate only 4,000 units per day against 24,000 units produced by a thermal power plant of the same capacity. So, a target of one lakh MW of solar power will be equivalent to 16,667 MW of thermal power only. Recently an idea has been floated to generate enough renewable energy to replace all thermal power plants of the country. The idea is laudable but ambitious given the rising power demand. Also, you require 1500 sq miles of land to set up solar power panels to generate 12 lakh MW of solar power to replace all thermal power stations with a total capacity of two lakh MW.

Water heating

Solar water heaters at affordable cost were developed long back in 1975. Presently, the cost of a 100-litre capacity water heater(sufficient for a small family) costs Rs 24,000 after availing a subsidy of Rs 6,000. Its payback period comes to four years assuming that it saves ten units of power by replacing the electric geyser. If every household in tri-city area of Chandigarh (Chandigarh, Panchkula and Mohali with roughly four lakh users of electric geysers) starts using solar water heater in place of electric geysers then savings will be to the tune of 40 lakh units per day. Unfortunately, the number of solar water users is only notional. The reason for this lopsided use is that neither the Central government nor the states take any interest in promoting the use of solar water heaters.

Solar cooking

Like water heaters, solar cookers too were developed in 1975. A box type solar cooker (sufficient to cook food, except chapatis, for a small family) now costs Rs 2,000. Community solar cookers were also developed. Considering the cost of cooking gas saved, it's payback period comes to only two years. Now, if all the food in army messes, hostels, hospitals, police and households were to be cooked with solar cookers, you can imagine the amount of cooking gas saved per day. The saving in terms of supply of gas cylinders may be as high as 60 per cent.

Cooking gas is originally imported from Qatar through GAIL and saving in gas consumption directly translates to savings in foreign exchange. Another advantage of solar cooking is that the cooked food is more nutritious because slow heating which prevents denaturing of proteins.

Power generation

Use of photovoltaic cells to generate power for commercial purposes is a relatively recent phenomenon. The Government of India introduced a scheme to purchase power from solar power producers in 2008 at the rate of Rs 17.41 as the cost of solar cells in those days was very high. This experiment triggered the craze of solar power producers to come forward to set up solar plants and gradually lower the rates over the years as low as Rs 3 per unit and solar power became competitive with conventionally produced electric power. National Thermal Power Corporation came forward to purchase the entire power produced by these plants. This policy resulted in installing a number of solar power plants and the total capacity reached 35,000 MW by the end of the year 2019. The beauty of a solar power plant is that its gestation period is very small and a 100 MW power plant can be installed within six months. Also, very few clearances are needed to start the construction.

The limitations of installing solar power plants are: Firstly, it requires 4.5 acres of land to generate one MW of power; secondly, there is a lack of factories set up for manufacturing solar cells; thirdly, a National Solar Power Corporation (on the lines of NTPC and NHPC) was not set up to install it's own power plants. Now, only two years are left to meet the target of generating 1 lakh MW power by 2022. The achievement of developing a balance of 65,000 MW of power in just two years is a huge challenge.

Rooftop panels

Haryana government had introduced an innovative scheme in 2015, directing all households(with a plot area of 500 sq yards or more) and institutions to set up rooftop solar power plants of capacity equal to 5 per cent of applied load subject to a minimum capacity of one KW. Unfortunately, this scheme was never pursued and only a few houses or commercial buildings set up the solar plants at the rooftop. The average cost of installation is Rs 42,000 per KW after availing the subsidy. The payback period is only four years. The additional beauty of this mode of power generation is the complete absence of line loss. Again, citing the example of the Tri-city area of Chandigarh, if every house and institutional area put up a rooftop solar plant of 2 KW capacity or more as per Haryana state formula, then 1,000 MW of power can be produced without any hassle. You can imagine the scale of power that can be produced if the Haryana directive is applied throughout the nation. We may be able to shut down 60 per cent of existing thermal power plants in this scenario.

Bottom line

There is an unprecedented revolution waiting to happen in the field of solar energy development which no other country can bring about because of lack of surface area and amount of sunshine. It is our great folly that we are not using this inexhaustible treasure of energy and prosperity. Development of solar energy is, therefore, rightly called the lowest hanging fruit of a vibrant economy.

Views expressed are strictly personal