Source: Subhra Priyadarshini
Environmental threats and rising costs have proven challenging for coal-based and nuclear thermal power plants while solar power remains expensive. The joint study by Lawrence Berkeley National Laboratory, Itron Inc., and Black and Veatch now shows that India's wind power potential is greater than previously estimated and, if tapped, could become the most viable alternate energy option for the country.
Previous estimate of India's wind energy potential pegged it at 103 gigawatts (GW). The new study says it could be anywhere between 2006 GW and 3121 GW. The researchers made a fresh estimate after observing an anomaly in two recent studies1,2 that showed India's onshore wind potential to be greater than 1000 GW in sharp contrast with a previous estimate of 103 GW.
To make the fresh estimate, the researchers considered publicly available Geographic Information System (GIS) data on topography and land use and cover (LULC) excluding parameters such as areas with low quality wind potential, slopes, elevations, forests, snow-covered areas, water bodies, urban and protected areas. They estimated wind energy potential for turbines at 80m, 100m, and 120m hub-heights.
The hub-height is the distance from the turbine platform to the rotor of an installed wind turbine and indicates how high the turbine stands above the ground, excluding the length of the turbine blades. They also calculated annual average wind power density (WPD) and wind speed data at an elevation of 80m, 100m, and 120m for each 5 km by 5 km cell in India.
The results showed that the total techno-economic wind potential in India ranges from 2,006 GW at 80m hub-height to 3,121 GW at 120m hub-height. The techno-economic potential estimated in this analysis is at least 20 times that of the official Indian estimate published by Chennai-based Centre for Wind Energy Technology (CWET) at 80m hub-height3.
Researchers Amol Phadke, Ranjit Bharvirkar and Jagmeet Khangura estimated that the land area available for potential wind power development ranges from 281,432 km 2 to 425,795 km 2 at 80m and 120m, respectively. The total land area necessary for high quality techno-economic wind potential of 543 GW (at 80m hub-height) is 60,362 km2 .
According to the new estimate, more than 95% of the techno-economic wind energy potential is concentrated in just five states in southern and western India – Tamil Nadu, Andhra Pradesh, Karnataka, Maharashtra, and Gujarat.
Interestingly, the state with the overall largest resource is Karnataka (around 655 GW at 80m) while the state with largest best-quality resource is Tamil Nadu (around 65 GW at 80m). From a cost-effective perspective, the full development of best-quality wind resources is feasible in Tamil Nadu — which already leads all states in installed wind capacity — would yield a capacity of 65 GW at 80m hub-height.
The researchers say that the estimates regarding yields and the extent of land most suitable for wind power development in India are not detailed enough to determine sites for an actual wind generation facility and predict its exact output. These estimates will be useful in policy-making, they conclude.
"The study clearly illustrates the use of modern software tools and techniques that can be applied to the assessment of wind energy potential," says K. Boopahti, head of Wind Resource Assessment Unit at CWET, Chennai. As the unit cost of electricity generated from wind energy in India is cheaper than imported coal, natural gas, diesel or solar power, it will certainly be a viable option, Boopathi adds.
