Rooftop—A Veritable El Dorado of Electric Power. It is incredible but true that the Sun can provide all the energy needed by man. If properly harnessed, sun rays reaching the earth in one second would be able to meet two hours’ global energy needs. Modern technology permits conversion of solar energy into electricity by means of what are known as solar panels. India’s tropical climate with over 300 days of clear skies makes the country an ideal venue for efficient solar power generation either from roof-tops or pieces of open land. The main advantage of solar power over thermal power is that it is “clean”; the conversion does not leave any carbon footprint. Solar power is also sustainable as the sun is a perennial energy source. In the past, when technology was in its infancy, solar power production was expensive and of poor efficiency, but now it is quite profitable to set up these power plants.
Promotion of solar power generation was taken up by the Ministry of New and Renewable Energy (MNRE) through the National Solar Mission launched in 2010. The production target, revised many times, presently stands at 100,000 Megawatts (MW) of power by 2020 generated through land-based (60,000 MW) and rooftop (40,000 MW) solar plants. However, an achievement so far has been only 35,000 MW for land-based and 4,000 MW for roof-top categories. We have to go a long way still.
Rooftop—A Veritable El Dorado of Electric Power. What is a Solar Panel? The photovoltaic cell is the heart of the solar power plant. A semi-conductor material, silicon, mounted below a glass sheet collects sunrays and emits electrons to cause a DC electric current to flow in a circuit. An inverter converts this photo-electric DC power into AC power. The efficiency of release of electrons and of harnessing them into power generation is determined by the quality of technology of which many are available in the market with different price tags.
Merits of Solar Power Generation: Apart from its non- polluting nature and sustainability mentioned earlier, solar power generation has other merits too. The plant works for 20-25 years without posing any maintenance hassles. Unlike other power plants, this does not produce any sound. The rooftop version of the plant does not demand any new space since it is set up in an area of the house left unutilized. Since no inputs are needed, the power production is immune to general cost escalations. An added benefit is the heat shield the solar panel offers to the open terrace. Though primarily meant to meet the needs of the household, since the system is usually connected to the grid, the excess power automatically gets “sold” to the electricity distribution company (DISCOM). Large terrace spaces and tiled sloping roofs can thus be utilized to produce power that would fetch good additional income for the household. Although the overall power availability in rural India has improved considerably, frequent outages compel people to rely on diesel generators which become unnecessary when solar panels are set up.
Other Features: A grid-connected solar panel of 1 Kilowatt (KW) capacity, yielding a nett 4 KWH (units) per day will occupy only an area of 100 sq. ft. of terrace or roof space. Since most homes will need more power, a 2 KW solar panel occupying 200 sq. ft. will be better. The installation will cost Rs.75, 000 and Rs.145, 000 respectively for these two panels. Cost per KW comes down with the capacity of the plant.
The MNRE, Govt. of India, offers a capital subsidy of 40% for domestic roof-top solar panels of 1-3 KW capacity and 20% for bigger plants up to 10 KW. Residential societies are also eligible to get 20% subsidy for roof-top units up to 500 KW. Many State governments too offer subsidies at different rates making the investment on rooftop solar plants more attractive.
Intervention Needed from Govt. :
The Solar Mission has not lived up to its reputation as evident from its 10-year record. The enormous potential of the solar panel is yet to capture people’s imagination. Information on the merits of the new technology and its exploitation through roof-top panels is largely unknown to the common man. A proactive publicity campaign is the need of the hour. Advertisements and publicity write-ups in print and electronic media, seminars and contact programmes involving NGOs, DISCOMS & companies setting up solar panels, etc., can go a long way in stimulating people’s interest. The disbursement of Govt. subsidy which at present is cumbersome needs to be simplified. The installing companies and banks should be urged to provide EMI facility for setting up solar units. DISCOMS should be encouraged to adopt the Kerala model in which the house owner leases out the terrace space to the Electricity Board to set up its own solar unit. A certain percentage of power generated is given to the house owner by way of lease rent.
As hinted earlier, the achievement so far has been only 10% of the Govt.’s own rooftop solar power production target of 40,000 MW by 2022. The author would like to emphasise that the scope for power production far exceeds the Govt.’s own target. This is so because if all the 38 million concrete houses in India come forward to set up solar panels of 200-500 sq. ft., the total power production can be a whopping 76,000 -190,000 MW. If in addition, all the sloping roofs of the tiled category in the country are fully covered with solar panels, the power output would go beyond the realm of one’s imagination!