Power needs becomes a point of concern when one talks about ‘Smart Cities’.
Wind Energy can prove to be a game changer. India’s wind potential is 302 GW (some say it could be higher than 1000 GW). India Energy Security Scenarios 2047 show a possibility of achieving a high of 410 GW of wind by 2047.
The government of India has been actively pursuing power generation from wind. India has also become a signatory to the COP21 Paris Climate Conference and has committed to generating 60 GW power from wind by 2022 out of the 175 GW Renewable Energy (RE) generation target.
Land based Wind Turbine Power (LBWTP) currently generates about 28,082 Mw of power as on December 31, 2016. Coastal states of Tamil Nadu (TN), Maharashtra and Gujarat are amongst the top three contenders with on-shore installed wind power plant capacities in excess of 4000 Mw. Interestingly, Off-shore Wind Turbine Power (OSWTP) has been projected to have significant potential since India has a long coastline of 7516 km. Gujarat has taken the step towards establishing India’s first OSWTP plant by signing an MoU with Samiran Udaipur Windfarms Limited (SUWL), worth Rs 6500 Crore, having an installed capacity of 500 Mw. The plant would be setup about 12 nautical miles (22.22Km) from the Gulf of Kutch.
Expert views
Rajesh Katyal, Deputy Director-General of National Institute of Wind Energy (NIWE), comments, “Eight zones with High Wind Flow (HWF) have been earmarked in (TN) and Gujarat for setting up of OSWTP plants.”
Dr. M.V.Ramana Murthy and Dr. M.A. Atmanand of the National Institute of Ocean Technology (NIOT) comment, “While LBWT Pcapital expenditure (CAPEX) stands at Rs 6.71 Cr, OSWTP CAPEX for Rameshwaram in TN stands at Rs 13.79 Cr. Operations and maintenance expenditure or OPMEX for LBWTP is Rs 3.46 Cr while for OSWTP (Rameshwaram) is at Rs 13.84 Cr. Nevertheless, net profit generated from LBWTP is Rs 6.75 Cr while that for Rameshwaram is Rs 9.77 Cr. Power Generation from LBWTP stands at 4.20 Kilowatt/hr (KW/hr) while for OSWTP it stands at 10.38 KW/hr.’
S Gomathinayagam, DirectorGeneral of National Institute of Wind Energy says, “International Electro technical Commission (IEC) reports play an important role in understanding the dimensions of wind power. IEC experts say that turbines in lower wind speed (Class III) locations with an annual average wind speed of 7.5 metres/second at a given rated power will need a larger rotor to capture the same amount of energy as a similar turbine at a medium wind location (Class II) site with an annual average wind speed of 8.5 metres/second. Due to the larger rotor, costs escalate for offshore wind turbines.”
Katyal also mentions, “Despite the fact that the CAPEX and OPMEX for on-shore wind power is less than its off-shore counterpart, the power generation and life of OSWTP is higher. On-shore wind speed is about 5 meters/ second while off-shore wind speed is at 8.65 meters/second. While a typical LBWTP would be functional for only 5 months in a year, the OSWTP would be functional for almost 10 months. The monsoonal winds have a great role to play in this.”
Global practices
International initiatives in wind power particularly off-shore wind power can serve as a crucial learning lesson. German manufacturing and electronics conglomerate Siemens is the turbine manufacturer for the world’s largest wind farm-The London Array. London Array, located about 20 Km off the Kent and Essex coast, is the world’s largest offshore wind power plant with an installed 175 wind turbines-a milestone in the development of offshore wind power. Siemens supplied and installed the 175 wind turbines, each with a rotor diameter of 120 meters and a rating of 3.6 MW. 33 kV power from the turbines is transported via underground sea cables (USC) to offshore substations where it is boosted to 150 kV. USC transmit this to four onshore transformers, enclosed in their own individual noise enclosure, which further boost this to 400kV before transmitting to consumers.
Siemens’ offshore direct drive technologies (DDT) wind turbines, between 2011 and 2017, generated an enormous 2.5 Terawatt per hour (TWH) of clean energy which translates into reduction of 1.25 metric tonnes of CO2 emissions or saving of 5 billion litres of freshwater. The management of wind farms translated into creating 300,000 jobs.
Denmark in 2015 exceeded its electricity demand by 140 per cent. Interconnectors allowed 80 per cent of the power surplus to be shared equally between Germany and Norway, which can store it in hydropower systems for later usage. Norway and Sweden have seasonal storage hydro systems with the reservoir dropping to its minimum around week 16, at 20-50 per cent. During this time, wind energy from Denmark proves a boon. Transmission lines can handle electricity exports of 1500 MW and imports of 950 MW. Hydropower from Norway and Sweden supplement electricity during periods of low wind in Denmark. Moreover, excess wind energy in Denmark, is also stored as heat energy in hot water tanks in buildings to reduce CO2 emissions.
A village in Tamil Nadu has shown a way of benefiting from net metering. This village Odanthurai, invested 1.5 Cr in buying a 350 kW windmill. Out of the total 6.75 lakh unit generated, the village uses 4.75 lakh units and sells the remaining 2 lakh to the Tamil Nadu Electricity Board, earning 20 lakh every year
The Indian experience
Coming to the Indian perspective, onshore wind farms have created close to 500 jobs and increasing. As per Global Wind Energy Council (GWEC) 2015 estimates, LBWTP and OSWTP can potentially reduce CO2 emissions by 203 million tonnes if both technologies are upgraded and sustained.
At the global and national level, wind power particularly OSWTP faces certain hindrances. Firstly, grid reliability is a major issue. Transporting power from energy rich areas to industrial corridors is a major task. Centre for Science and Environment (CSE) report ‘State of Renewable Energy In India’ found that due to calculation errors in factoring in appropriate wind speed and insufficient installation area of 765 kV transmission towers, TN electricity Board (TNEB) wasn’t successful in providing LBWTP from the sub-station to the consumer. Nevertheless, a village in TN has shown a way of benefiting from net metering. This village Odanthurai,invested 1.5 Cr in buying a 350 kW windmill. Out of the total 6.75 lakh unit generated, the village uses 4.75 lakh units and sells the remaining 2 lakh to the TNEB earning 20 lakh every year.
Environmental risks associated with wind power also pose a problem. OSWTP can affect movement of incoming bats and birds as well as marine ecology when they come in the vicinity of the wind turbine. Closer home, the ‘Nallakonda Wind Farm’ led to the destruction of 2833 hectares of forest land at Kalpavalli in Anantpur, Andhra Pradesh. MNRE and other ministries need to engage in ‘Environment zoning’ so that only non-ecological barren land is used for setting up of wind farms. Despite all these, wind power carries a lot of promise and can solve India’s energy crisis if put to optimal use. Political will and innovation are necessities towards an energy rich India.