The joint-venture, known as Skylark, aims to invest £500 million into onshore wind projects to supply energy to 200,000 homes by 2018.
Three development sites, representing a generating capacity of 100MW, have already been identified, a statement from Ecotricity said.
The company said it plans to use its experience in renewables development to design the wind farms and achieve the planning consents whicle Skanska will use their experience in construction to build them.
“It’s a simple partnership that will help to bring energy independence to Britain using green energy made in Britain,” said Ecotricity founder Dale Vince said.