Can Solar Energy save the Ganga?

1. Can Solar Energy save the Ganga? Electric Solar Panel for Power Generation Dams| Hydropower| Environment| Coal| Thermal Power| Uranium| Nuclear Power We have been suggesting that we should not make dams on the Ganga for the generation of hydropower in order to conserve the river. Question is: How will we meet our requirement of electricity if we do not generate hydropower? We do not have large deposits of coal, so we cannot develop thermal power. We do not have large deposits of uranium, so we cannot develop nuclear power. The only alternatives we have are hydropower and solar power. According to the report of National Institute of Solar Energy the solar power potential is about 750 GW in India whereas according to a report published in “The Pioneer,” the total installed capacity of the hydropower is 306 GW (One Gigawatt or GW = 1,000 Megawatt or MW). The Government has followed the right policy in increasing the target of solar power generation to 100 GW. However, at the same time the Government wants to increase generation from hydropower. This requires reconsideration. Solar Energy| Rivers Forests| Rajasthan| Solar Power Cost The generation of solar power is more environmentally friendly than hydropower. It does not harm the rivers and forests. Solar power panels are installed in barren areas like desert of Rajasthan and the Deccan Plateau. Solar power is also much cheaper than hydropower. The present cost of solar power is about Rs 3 per kWh, whereas it is Rs 8 to 11 per kWh from hydropower. Therefore, solar power is both cheaper and environment friendly and it should be promoted on priority basis. As stated above, the potential of solar power is estimated at 750 GW while that of hydropower is estimated at 306 GW. Therefore, it is possible for us to meet large part of our electricity requirements by solar power. We may consider hydropower only after we have exhausted the solar power potential. The problem with solar power is that electricity can be produce only in daytime when sun shines whereas the demand of electricity is more in morning and evening when there is no

2. sunlight. On other hand, the advantage of the hydropower is that it can produce electricity anytime of the day. Hydropower projects store water in day and night and generate electricity in morning and evening when the demand is high. This is the reason that hydropower generation is preferred over solar power generation. Production| Pump Storage| Reservoir| IIT Kanpur Electricity The solution is to combine hydropower with pump storage. We can pump water from a lower reservoir to a higher reservoir during the day when the solar power is available; and release it during the evening and morning when we need electricity, known as “peaking” power. This is shown in the picture. Pump Storage System Can Be Used For Converting Solar Electricity into Peaking Supply The Central Electricity Authority has estimated that the cost of converting solar daytime electricity into peaking electricity through a pump storage plant is about 30-40 paise per unit (kWh) (see here). A study by IIT Kanpur has estimated the cost as less than 30 paise: “It is found that the presence of pumping-based storage facility translates to a value of Rs. 0.297/kWh in the overall cost.” (See here). Solar Power| Pump Storage| Hydropower Cost| Environment This means that solar power combined with pump storage scheme can be supplied in morning and evening at a cost of about Rs 4 per kWh (being Rs 3 cost of generation and Rs 0.50 cost of conversion). On the other hand, the hydropower costs between 8 to 11 rupees per kWh for the same peaking supply. Therefore, we must go for combination of solar power with pump storage; dismantle all hydropower projects; and save our rivers and environment.