Board (BBMB), a state-owned enterprise in north India, has an installed capacity of 2.9 GW. The generation cost after four decades of operation is about per kWh. BBMB is a major source of peaking power and black start capability to the northern grid in India and its large reservoirs provide wide operational flexibility. BBMB reservoirs also supply water for the irrigation of of agricultural land in partner states, enabling the green revolution in the northern India. The International Hydropower Association estimates that the total hydropower potential in India is 660,000 GWh/year, of which 540,000 GWh/year (79%) is still undeveloped. India ranks as the fourth country in the world by undeveloped hydropower potential, after Russia, China and Canada, and fifth by total potential, surpassed also by Brazil. Pumped storage units India has transformed from an electricity deficit state to an electricity surplus state. Peak load shortages can be met making use of pumped storage schemes which store surplus power to meet peak load demands. The pumped storage schemes also contribute secondary, seasonal power at no additional cost when rivers are flooded with excess water. India has already established nearly 4,800 MW pumped storage capacity with the installation of hydropower plants. Pumped storage units can also be used as pumping stations to supply river water for upland irrigation, industrial needs, and drinking water. In a tropical country like India, abundant water for agriculture is needed due to a very high annual evaporation rate. The amount of water necessary to meet this demand can be harnessed from India's rivers via pumped storage units. Food security in India is improved with water security which in turn is possible from the energy security to supply the power needed for the pumped storage schemes. More and more solar power generation is becoming available at cheaper cost and it has advantage in terms of environmental impact. Solar power can meet daytime and night time energy demands with the help of pumped storage units. Many of the existing hydro power stations on the west-flowing rivers located in the Western Ghats of Kerala and Karnataka are to be expanded to include pumped storage units in an effort to solve the water deficit of east-flowing rivers like the Kaveri, the Krishna, etc. See also List of hydro power stations in India Electricity sector in India Energy policy of India Pollution of the Ganges Water resources in India Indian Rivers Inter-link