US tech giant Google has signed up for its 17th renewable energy project, to put $145 million towards an 82 megawatt solar project being built by SunEdison on a former oil and gas field.

The deal, announced last week, puts the internet search company’s clean energy investment tab at more than $1.5 billion, for projects spanning three continents and totalling a capacity of more than 2.5GW.

This latest, the “Regulus” solar project in Google’s home state of California, will be SunEdison’s largest in North America once finished, comprising more than 248,000 monocrystalline solar PV panels spanning 737 acres.

“Over the years, this particular site in California has gone from 30 oil wells to five as it was exhausted of profitable fossil fuel reserves,” writes Google’s renewable energy principal Nick Coons on Google’s blog. “The land sat for some time and today we’re ready to spiff things up.”

The owner of the system is TerraForm Power, which will sell the output to Southern California Edison through a 20-year power purchase agreement. Prudential Capital Group and Santander Bank both provided term financing.

As Forbes reports, Google’s various long-term agreements for renewable power generated approximately 870,000 megawatt-hours last year, covering 23 per cent of the company’s total power needs. Between those contracts, the green power it buys from the grid and its own on-site projects, it sources about 35 per cent of its electricity from renewables.

In April, Google announced a huge deal with Iowa utilities to supply its data center facilities there with up to 407MW of wind energy, as well as a partnership with solar giant SunPower, to get in on the burgeoning US residential solar leasing market.