India's ambition of deploying 175 GW of green energy from renewable sources by 2022 was a big challenge, Railway Minister Suresh Prabhu said on Saturday.
Solar energy was the ultimate solution for India, Prabhu said at the Global Energy Technology Summit 2015 organised by NTPC Ltd here.
He also said that wind and solar were the real sources of energy.
Needing an investment of $150 billion, the Indian government aims to deploy 100 GW of solar energy and 60 GW of wind energy in the next seven years.