Google has made its third bet on green energy in the space of three months, with a deal to buy all the electricity generated by four Swedish wind farms for 10 years.

The transaction is similar to one that the technology giant sealed seven months ago with Nordic wind developer O2, when it agreed to buy the power produced by a 24-turbine wind farm in northern Sweden for a decade.

No financial terms of either deal have been disclosed, but the latest move comes a month after Google agreed to invest $75 million in a Texas wind farm, and two months after it committed nearly $80 million to six utility-scale solar plants in California and Arizona.

Its latest Swedish deal, announced yesterday, will finance the construction of four new wind farms in southern Sweden by another Nordic developer, Eolus Vind AB.

The 29-turbine project is due to become fully operational in early 2015 and has a total combined capacity of 59 megawatts.

Overall, Google has invested more than $1 billion in wind and solar projects in recent years, in an effort to boost the growth of renewable energy and generate financial returns.

"We're always looking for ways to increase the amount of renewable energy we use," said Francois Sterin, Google's director of global infrastructure.

Although Google will not use the electricity from the Swedish wind farms directly itself, it points out that they generate the same amount of power that the group uses at its Hamina data centre in Finland, which is undergoing a €450 million expansion to triple its size.

Apple has said it will power all its facilities with energy from renewable sources. Microsoft and Facebook both announced new wind power investments in the US in November. However, the size and global reach of Google's renewable energy investments make it the technology sector's green leader so far. – (Copyright The Financial Times Limited 2014)