SCOPE FOR RENEWABLE ENERGY

Figure 13 illustrates that the Gangetic plains (Trans, Middle, and Upper) Plateau region (Central, Western, and Southern), Western dry region, Gujarat Plains, and hill region as well as the West Coast plains and Ghat region receives annual global insolation above 5kWh/m2/day. These zones include major federal states of Karnataka, Gujarat, Andhra Pradesh, Maharashtra, Madhya Pradesh, Rajasthan, Tamil Nadu, Haryana, Punjab, Kerala, Bihar, Uttar Pradesh, and Chattisgarh. The eastern part of Ladakh region (Jammu & Kashmir) and minor parts of Himachal Pradesh, Uttarakhand, and Sikkim, which are located in the Himalayan belt also receive similar average global insolation annually. These regions with a viable potential constitute solar hotspots covering nearly 1.89 million km2 (~58 per cent) of India (Figure 14) with the favourable prospects for solar-based renewable energy technologies, which could help meet her escalating power requirements in a decentralized, efficient, and sustainable manner. A techno-economic analysis of the solar power technologies and a prospective minimal utilization of the land available within these solar hotspots demonstrate their immense power generation as well as emission reduction potential. A major thrust for R&D in solar technologies is essential to lower the generation cost and enable competition with the conventional fossil fuel-based options.

Regions receiving global insolation of 5kWh/m²/day and above can generate at least 77 W/m2 (actual onsite output) at 16 per cent efficiency. Hence, even 0.1 per cent of the land area of the identified solar hotspots (1897.55 km2) could deliver nearly 146 GW of SPV-based electricity (379 billion units (kWh) considering 2600 sunshine hours annually).  Figure 14 gives the district wise solar power density of the country. This power generation capacity would enhance considerably with the improvement in efficiency of SPV technology. Solar technologies have the potential to offset a huge volume of GHG emissions as demonstrated and help realize a low carbon economy at a faster rate. It will create numerous employment opportunities, especially at the village level. Learning from other developing countries as well as its own past experiences, India can be a world leader in solar power generation. With an ambitious solar mission, and positively evolving policy instruments, the nation will rightly adorn the epithet of ‘Solar India’ in the near future.

Figure 13: Annual average global insolation map of India showing the isohels and solar hotspots	Figure 14: District-wise solar power density of the country

 

The National Solar Mission (NSM) launched in 2009 by the Government of India has given a great boost to the solar scenario in the country. The mission targets achieve 175 GW by the year 2022 which includes 100 GW from solar, 60 GW from wind, 10 GW from bio-power, and 5 GW from small hydro-power. The solar energy installation comprises of 40 GW rooftop and 60 GW through large- and medium-scale grid connected solar power projects. About INR 6,00,000 crores investment is expected for the commission of 100 GW solar projects (CEA – LGBR 2013). However, considering the current level of T & D losses in a centralized system, inefficient, and unreliable electricity supply, it is necessary to promote decentralized energy generation. Small capacity systems are efficient, economical, and more importantly would meet the local electricity demand. The incentives could be

• Solar Rooftop PV systems can be installed on residential/commercial/industrial buildings in the state. Excess generated energy can be fed to the grid with net metering with incentives (of INR 9.56/unit—without subsidy and INR 7.20/—with subsidy).
• Buyback programmes for the electricity generated at household level and in micro grid—GBI of INR 9.56 for electricity generation (< 5 kW) feeding to the grid by SPV.
• Install solar rooftops in all new government/local body buildings—implementation of solar rooftops could be in a phased manner in the existing government/local body buildings, etc.
• Commercial lighting in advertisement boards should only be from RE sources. Complete ban on usage of grid electricity for these purposes.
• Impetus to energy research through generous funding for the R & D activities to ensure further improvements in the grid, technologies, two-way communication energy meters (to connect rooftop generation with existing grid),  efficient luminaries’ production, low cost wiring, switchgears, appliances, etc.
• Energy education (focusing mainly on renewable energy technologies, end-use energy efficiency improvements, energy conservation) at all levels. School curriculum shall include renewable energy (RE) concepts.
• Awareness about energy independence and the necessity of RE sources in the present gloomy energy scenario to the consumers.
• Education and awareness about applications and importance of renewable energy sources.
• Capacity building of youth through technical education for installation and servicing of SPV panels.
• Setting up service centers in block development offices to meet the requirement of service support for RE technologies (solar, biogas, energy efficient chulas, etc.).

• Wind Energy: India ranks fifth (after China, US, Germany, and Spain) with over 19 GW wind installed capacity. Wind energy accounts for 8.5 per cent of the total installed capacity. Figure 15 gives the district-wise wind power density potential in India. The total wind energy potential in country is estimated as 49.13 GW in which about 38 per cent has been utilized for energy generation (Sharma et al., 2012). The state of Tamil Nadu leads in wind energy extraction with the installed capacity of 6,286 MW followed by Maharashtra (2,400 MW), Gujarat (2,337 MW), and Karnataka (1,773 MW) (C-WET 2012).

Energy extraction from wind resources primarily depends on the wind speed available in the region. The available wind energy potential is directly proportional to the wind speed and area swept by the wind turbine. Hence, the primary need is to assess the annual wind speed of the region which indicates the potential regions for energy extraction. The coastal region of the country experiences high wind speed which ranges from 3 to 5 m/s annually. The southern and central part (west coast) of the country experiences higher wind speed during monsoon (June to September) which will be more than 5 m/s. During winter, the high elevated region of the country experiences high flow of wind that ranges from 4–5.25 m/s (Ramachandra and Shruthi 2007). Estimation shows that the western coast (Karnataka, Tamil Nadu, Kerala, Maharashtra, Gujarat) and plains (Rajasthan, Gujarat, Karnataka) are the ideal places for wind energy harvesting where the annual average wind speed is higher. However, there is vital scope for decentralized wind energy generation in hilly regions (such as Jammu and Kashmir, Himachal Pradesh) and islands (such as Anadaman and Nicobar, etc.). Distributed wind applications in water pumping and milling could meet the energy demand for irrigation and domestic sector of the region (Ramachandra and Krishnadas 2012).

Figure 15: District-wise wind power density potential in India

• Bio-energy: Bio-energy is a prominent component of total primary energy consumption in India. About 70 per cent of the population lives in the rural region of the country where agriculture and horticulture are the primary occupations. Residues obtained during the processing of the yield are one of the major sources of bio-energy in the country (Ramachandra et. al 2014). Forest residues and fuel wood are the primary energy sources for heating and cooking in rural India. The sector-wise available bio-energy is estimated and compared with the energy demand. Figure 16 gives the state-wise supply to demand ratio of biogas and biomass energy, which shows the ratio of 0.25–0.5 for most of the states. Cattle dung and biogas generation meets the significant domestic energy demand for cooking in rural and suburban areas. The north-eastern part of the country with good forest cover shows a better resource status.

The Ministry of New and Renewable Energy (MNRE), Government of India, has come up with policies and plans to encourage bio-energy utilization in the country. The country has a total installed capacity of 1,284 MW biomass power plants and 2,392 MW of bagasse generation plants which are synchronized with grid (MNRE 2013b). Waste to power generation grid interactive plants of about 100 MW installed capacity demonstrate the productive way of municipal solid waste (MSW) management (MNRE 2013a; Ramachandra 2009b). The country has more than 750 MW installed capacity off grid/captive power plants which gives the new avenues for decentralized power generation (MNRE 2013b). Improvement in bio-energy technologies (BETs) and effective management of wasteland, friendly policies, and incentives would certainly increase the energy potential and capacity addition using more bio-energy resources (Singh and Setiawan 2013).

Figure 16:  State-wise bioenergy and biogas status (supply/demand ratio)

• Biofuel: In the face of increasing CO2 emissions from conventional energy sources and the projected scarcity of crude oil, there is an immediate need for cost effective renewable alternative energy sources. Bio-diesel generation from gasoline secreting diatom solar panels is a revolutionary change to meet the future crude oil demand. Diatoms, the major group of planktonic algae, can be used sustainably for production of bio-fuel, by the usage of diatom-based solar panels. Studies have shown that diatoms could make 10 to 200 times as much oil per hectare as oil seeds. Some diatoms secrete more lipid content when subjected to unfavourable environment or culture conditions, such as nutrient starvation or extreme temperatures (Mahapatra, Chanakya and Ramachandra, 2014). Since diatoms multiply rapidly, they can double their biomass within an hour to a day’s time. Since each diatom creates and uses its own gas tank, it is estimated that diatoms are responsible for up to 25 per cent of global carbon dioxide (CO2) fixation. This shows that while diatoms can be cultivated for oil extraction, they can automatically reabsorb carbon dioxide in the process. Diatoms have the potential to meet the future oil demand which also plays a major role in CO2 absorption. This enables the scope for mimicking the natural process to extract oil which leads to sustainable growth (Ramachandra et. al 2013). 

Renewable energy technologies (RET) such as individual/community level rooftop installation of solar PV, biomass gasifiers, wind energy conversion systems, biogas plants, etc., have the potential to substitute grid electricity. Since the country receives solar insolation over 5 kWh/m2/day for more than 300 days annually, solar PV installation on rooftop and in wasteland could be viable option to build up the capacity. India has over 7,000 km of coastline which are high potential wind regions. Installation of wind turbine near sea shores (fraction of area) could generate enormous amount of energy which also adds to the natural splendour. Most of the Indian population residing in rural areas practices agriculture. Agricultural and horticultural residues have the potential to meet village level domestic energy demand through gasification. The prime advantage of this system is that it produces electricity, gas, and manure which can be returned to the farmer. These systems can be installed by individuals or as a community (pay for service) in larger scale which can also be connected to the grid. Hybridization of locally available RE sources makes the system more reliable, efficient, economically viable, and sustainable (Ghosh et. al, 2002; Balamurugan, Ashok and Jose, 2009).