There is no standard social discount rate and it changes depending on countries and specific considerations. The proxy that has been used by utilities or public organizations in several countries is around the expected future inflation rate as the minimum rate of return, which is specifically around 2% in USD. The discount rate will be in line with the cash flows, if they are in nominal or (limited) real terms, and the currency that is being used.

The higher the social discount rate is, the lower the attractiveness and the profitability of the project will be. From the social perspective, a relatively lower social discount rate would be given to renewable energy projects rather than traditional energy projects to help a country speed up the energy transition.