The public issue of "tax free, secured, redeemable, non-convertible bonds in the nature of debentures of face value of Rs 1,000 each" would amount to Rs 500 crore, the company said in a statement.
There would be an "option to retain over-subscription" up to Rs 500 crore for issuance of additional bonds, taking the aggregate to a total of Rs 1,000 crore, the statement said.
The issue which opened today will close on November 11 next month.
A K Capital Services and Axis Capital are the lead managers while Karvy Computershare is the registrar to the issue.
Currently, NHPC has an installed power generation capacity of 5,702 MW. It is awaiting approvals for about ten projects having total capacity of 8,801 MW.
Shares of NHPC were trading at Rs 18.75 on the BSE, up 0.27 per cent from its previous close.