Boston-based First Wind is operating or constructing renewable energy projects in the northeast, the west and Hawaii, with a combined capacity of about 1.3GW, which meets the annual needs of over 425,000 homes.

Solar power firm SunEdison said the acquisition will give it a foothold in the US wind market.

Based on the expected impact of the transaction, SunEdison increased its 2015 installation guidance from a range between 1.6GW and 1.8GW to a range between 2.1GW and 2.3GW.

SunEdison will buy more than 1.6GW of pipeline and backlog projects, which have been added to TerraForm Power’s call right project list.

The transaction includes an additional 6.4GW of project development opportunities.

TerraForm will add 521MW of First Wind assets to its portfolio under the transaction, with 1.6GW of projects anticipated to be dropped down in 2016 and 2017

TerraForm Power will acquire First Wind’s operating portfolio for an enterprise value of $862m.

The transaction, which is subject to regulatory approvals, is expected to be completed in the first quarter of 2015.

SunEdison president and chief executive officer Ahmad Chatila said: "The acquisition of First Wind transforms both SunEdison and TerraForm Power into diversified renewable energy companies and will make SunEdison the leading renewable power plant developer in the world."

First Wind chief executive officer Paul Gaynor said: "This new strategic organization will allow us to join with SunEdison to develop and invest in new, long-term-contracted, well-sited and well-run renewable energy projects that deliver clean energy to homes and businesses across the country and internationally.

"We will be able to leverage our strength in development and operations, proven during the completion of 1.5 GW of wind projects over eight years, with two world-class companies."

Image: First Wind is operating or constructing renewable energy projects in the Northeast, the West and Hawaii, with a combined capacity of about 1.3GW. Photo: Courtesy of First Wind.