The board of the investment trust say the funds will be used to finance the construction of the final two projects in its pipeline.
The share issue was over subscribed.
The investment trust has a target return of 8 per cent per annum before leverage, and 15 per cent per annum when leverage is considered.
Leverage involves the company raising an amount of capital from shareholders and then borrowing money on top of that (the leverage) with both amounts of money invested, and shareholder returns coming after the interest payments have been made.
The targeted annual return before debt is 7 per cent per annum. The trust has a current dividend yield of 6.2 per cent, and trades at a premium to its net assets of 8 per cent.
John Leggate, chair of the Gresham House Energy Storage fund said: “Strong investor demand means we can commit to further developing our pipeline thereby creating greater diversification and scale for our shareholders, while maintaining capital discipline.
"We are extremely grateful to our investors for their trust in Grid, and excited about the value that our installed capacity and growth strategy is expected to deliver.”