Most of the people today know about the uses of solar energy and why we should use it. With the rapid depletion of conventional, non-renewable sources of energy like coal, gas and oil, finding out ways to harness and increase the production of alternate, renewable sources of energy is on the rise. Can we harness solar energy and produce solar power in India?
India, being partly tropical and sub-tropical, receives sunlight all round the year. The amount of solar energy received by India is a whopping 5000 trillion KWH per year (Indian Power Sector, August 2014). But due to India’s land usage pattern, the country’s harness-able solar power potential has been estimated to be 750 GW. The National Solar Mission (NSM) was launched in 2010 by then Prime Minister Dr Manmohan Singh with a target to achieve 20 GW installed solar capacity by 2022. This figure was re-revised by current Prime Minister in 2014 and a huge target of 100 GW installed solar capacity was set by 2022 (MNRE). This mission is the world’s largest energy expansion program. The 20 GW installed capacity milestone was hit in the beginning of 2018, increasing the solar capacity of India by 370 per cent (Economic Times, January 2018). The International Solar Alliance, which has 121 solar resource rich members with its headquarters at Gurgaon, Haryana, has given India ‘JagatGuru’ status which means ‘world leader’.
However, there is a huge difference between installed capacity and the actual amount of electricity generated. The installed capacity of India in the year 2018 is approximately 20 GW while solar power in India that was generated in the year 2016-17 was 13.5 Billion Units (BU) of Electricity (Mercom India, 2017). This difference in installed capacity vs production can be seen due to many reasons. Solar energy is not present throughout the year in all areas of the country due to seasonal changes, diurnal changes, pollution, dust, storms and so on. In this way, the maximum capacity of a solar power plant is never fully achieved. Apart from this, the target of the NSM is to achieve installed capacity of 100 GW. The target for solar power in India has not been set as of yet. The Capacity Utilisation Factor or CUF is the real output of the plant, expressed by calculating the real output divided by the total capacity of the plant. We can measure the cumulative CUF of all the solar power plants of the country for the year 2017 through dividing real output/ total capacity.
|World||India||State/UT with most||State/UT with least|
|Installed Capacity (Rooftop + solar power plants + other sources)||300 GW (IRENA, 2016)||20 GW (MNRE, 2018)||Telangana (3GW) (Hindu Business Line, 2018)||Jammu &Kashmir, Goa, Mizoram, Nagaland and Dadra &Nagar Haveli:
Meghalaya has least installed (30KW)
|Rooftop||–||2 GW (approx.)||Tamil Nadu (Hindu Business Line, 2017)||Same as above|
|Electricity generated from solar energy||250 TWH (IRENA, 2016)||13.5 TWH or BU of electricity (Mercom India, 2017)||–||–|
|Total electricity generated||24,215 TWH or BU of electricity (BP Global, 2017)||1160.1 TWH or BU of electricity (IBEF, 2018)|
According to MNRE reports, Jammu and Kashmir has a potential to harness 111 GW of solar energy but they have no installed capacity as of yet. The state has got an approval to begin the construction of solar power plants. According to MNRE’s annual report of 2016-17, all major sectors like railways, airports, hospitals, educational institutions, government buildings of central/state/PSUs are being targeted to set up solar rooftop panels, besides the private sector. The Ministry has also tied up with Indian Space Research Organisation (ISRO) for Geo tagging of all the Rooftop plants using ISRO’s VEDAS (Visualisation of Earth Observation Data and Archival System) Portal.
Solar Power in India
Solar power in India is abundant and if every household had the ability to harness its energy, our country would be energy surplus. Solar power in India can be generated through:
- Photovoltaic (PV) Cells: PV cells are special, semiconductor cells that absorb the incident sunlight. In turn, electrons present in the cell get excited and produce Direct Current (DC). This effect is known as photovoltaic effect.
- Solar water heating: Rectangular chambers with flat-plate collectors, filled with water or any other fluid, are used in this process. These chambers are called solar collectors. The solar energy heats the fluid in the system which flows through the pipes in the solar collector, and transfers its heat to the water in the rectangular chamber.
- Passive solar energy systems: Systems that do not convert solar energy into mechanical or electrical output, but rather use the natural heat flow of the solar energy, are called passive solar energy systems. An example would be a greenhouse, where the heat stays trapped inside the glass box, and warms the space inside the greenhouse.
- Solar thermal electricity: This process is used to heat water by using mirrors and directing the heat coming from sunlight towards the water. The steam generated by the heated water drives the turbine, generating electricity.
- Solar heating and cooling: Instead of using electricity or any fuel like natural gas or oil to provide hot water, space heating, cooling, and pool heating for residential, commercial, or industrial areas, solar heating and cooling systems can be effectively used. This works on similar lines of solar water heating process.
The systems that are set up to harness the solar energy can be of two major types:
- Rooftop Solar Panels: Rooftop solar panels are useful for both, small and large scale consumption. The rooftops of housing complexes, government buildings, hospitals, offices, schools and other buildings can be used as spaces where rooftop solar panels can be installed. According to the data from MNRE, the installed capacity of rooftop solar panels in India as of February 2018 is 1080 MW or 1.08 GW.
- Grid-connected: Grid-connected or on-grid rooftop solar panels harness solar energy on a large scale and convert this energy into electricity. This electricity is then transmitted to the grid which in turn transmits this energy to all who are connected to the grid. Since solar energy is free, the policies of India support grid-connected systems and the prices for solar panels have dramatically reduced over the years many people are opting for this way of producing electricity. There are two ways of billing attached to this:
- Net-metering: Here the meter is bi-directional; it forwards when you consume electricity and it moves backwards when you produce electricity.
- Gross-metering: Here you have to pay your electricity bill based on your consumption. Separately, you get paid for the electricity you produce.
- Off-grid: An off-grid system does not transmit the electricity it produces; rather it stores the solar energy in batteries for self-consumption or small-scale consumption. The batteries get charged during the day and supply power during the night.
- Solar farms or solar power plants: Solar farms or power plants produce electricity for power-grids, so it can be distributed to all connected to the grid. They are used for large scale production, powering households, industries, hospitals and so on. Barren fields can be used to set up solar power plants. According to the data from MNRE, the installed capacity of ground-mounted solar panels or the capacity to produce solar power in India as of February 2018 is 18,503 MW or 18.5 GW.
Apart from heat and various applications, solar energy also provides the earth with light. This light can be used in the daytime to light up home spaces, office spaces etc by constructing skylights in houses or building huge windows with unbreakable glass in office spaces. This way, during the day, houses and offices will not need to use artificial lighting that consumes electricity. Meanwhile, outdoor lighting can be built with solar chargeable batteries so that they can be charged during the daytime and can be used in the night time. Other electrical devices can also be charged using solar chargers.
Apple’s headquarters in California are powered completely by renewable energy. Their buildings are furnished with solar panels all over them and the power generated from solar energy contributes hugely to their power consumption. If all Indian buildings and offices incorporated this idea, we would be in a much advanced position with production and consumption of power from solar energy.
Solar Power in India : State’s
As of December, 2016, Rajasthan ranks number one, followed by Jammu and Kashmir, Maharashtra and Madhya Pradesh in terms of potential to harness maximum solar energy in the country. In terms of installed capacity, Telangana tops the list. The largest solar power plant in the world is the Kurnool Ultra Mega Solar Park at Andhra Pradesh with an installed capacity of 1 GW. The world’s second largest solar power plant is also located in India at Tamil Nadu, named Kamuthi Solar Power Project, with an installed capacity of more than 600 MW. The issue is in finding the exact figures in terms of electricity produced by each power plant because the data given out by our government focuses on the installed capacity rather than the actual amount of electricity produced. Cumulatively, the southern states of India contribute about 40 per cent of the total installed capacity. Tamil Nadu has the highest number of solar projects lined up for 2018. Jammu and Kashmir, Goa, Nagaland and Dadra-Nagar Haveli also have solar projects chalked out and approved for the year 2018.
An amazing feat has been achieved by a much smaller union territory (UT) than any of these states. Diu Island, one of the union territories of India, which has a total area of almost 42 square km, is now housing a 9 MW solar park that is spread over 50 acres. This solar power plant has empowered Diu to produce its own electricity. Earlier, Diu had to import electricity from Gujarat to fulfil its electricity requirement. Today, Diu is capable of producing 13 MW of solar power (10 MW is cumulatively produced from various power plants and 3 MW is generated from rooftop installations of Photovoltaic cells) on a daily basis, which meets 30% of the UTs daily power requirement. Diu has become India’s first solar-powered union territory and has become a role model for other states and UTs (Times of India, March 2018).
Although India’s achievement in case of utilising solar energy for the country’s energy needs is a big step towards harnessing the most abundant renewable source of energy, our neighbouring country has taken gigantic strides in that direction. As per China’s ‘Made in China 2025’ plan, the transportation ministry’s science and technology department has come up with ‘smart roads for smart cars’. With China already in the lead in the world on the basis of installed capacity for producing solar energy, their latest accomplishment of constructing a road paved with solar panels, sensors and electric-battery recharges could accelerate the transformation of the global transportation industry. The road is built with transparent material so that the solar panels, which are placed underneath the roads, receive sunlight to recharge themselves to light up the highway as well as provide electricity to as many as 800 homes close to the highway. The roads are also designed to monitor temperature, traffic flow and weight load. If Indian roads could be designed in this innovative and productive manner, our country could also join the race for the top 5 leading countries in the field of solar energy.