Supported by the UK Government’s contract for difference (CfD) scheme, the 299MWe project will source wood pellets and chips from certified sustainable forestry in the US and Europe, to generate electricity.
The project, which already secured major permits required for construction and operation, is likely to create about 600 jobs during construction phase and around 100 full-time jobs once operational.
Macquarie Capital has started a debt raising process with financial close projected in the fourth quarter of 2015.
Macquarie infrastructure, utilities and renewables head Mark Dooley said: "As one of the first renewable energy assets to be project financed under the new UK CfD regime and the largest dedicated biomass project to be built in the UK, the project presents some challenges but also a great opportunity for the finance market.
MGT Power CEO Ben Elsworth said: "Following the sanction by the European Commission of the Project’s CfD earlier this year, the involvement of Macquarie as an investor and adviser represents another major step forward in the process to finance the project with the aim of starting construction on site by early 2016 at the latest."