The asset managing firm will issue new ordinary shares to institutional investors in order to repay its credit facility, used to acquire new projects.
The price of the new shares will be announced around 12 May and the placing will close on 26 May, the firm said.
JLEN's portfolio comprises onshore wind, waste and water processing, and solar facilities.
The London Stock Exchange-listed company owns 82.3MW of onshore wind in the UK, including the 26.6MW Hall Farm project in North Yorkshire. Hall Farm was completed in 2013 and uses 12 Senvion 2.05MW turbines.