Canadian Solar has sold three large-scale solar PV plants to TransCanada, the oil and energy infrastructure company that is also behind plans for the controversial Keystone XL tar sands oil pipeline.

Each of the three plants has a generation capacity of 10MW, completed for a combined cost of around CA$182 million (US$162.8 million). According to a statement, this means TransCanada has invested close to CA$400 million (US$357.8 million) in solar to date.

The three plants, Liskeard 3, Liskeard 4 and William Rutley, are already generating electricity, which is sold under a 20-year power purchase agreement (PPA) to the Ontario Power Authority. Canadian Solar signed a deal to sell PV plant projects to TransCanada in 2011, with four generation facilities already sold through the deal previously.

Referring to the latest sale, TransCanada’s chief executive officer and president, Russ Girling, talked up his company’s diversified portfolio of assets, which include natural gas and liquids pipelines in addition to a growing focus on emissions-free energy sources.

“Each year, we do more to reduce our own emissions and develop technologies to help us operate in a more environmentally sustainable way, while ensuring that Ontario's energy consumers continue to have their needs met,” he said.

"These solar acquisitions are an important part of our US$38 billion capital program and add 20-year revenue streams in a core geography that are backed by a high quality credit and long-term customer relationship.”

TransCanada has invested a total of over CA$5 billion (US$4.47 billion) so far in emission-free energy, including wind and hydro.

The company’s planned Keystone XL pipeline meanwhile, has attracted high profile protests, including a recent benefit concert by veteran country-rock musicians Willie Nelson and Neil Young, while the jailing of a 78-year old protestor and other incidents have also drawn a great deal of publicity. The pipeline would send tar sands oil from Canada to the US Gulf Coast and still requires approval from US President Obama before it can go ahead, as it would cross an international boundary. The Wall Street Journal also reported in September that the budget for the project, originally announced at an estimated US$5.4 billion, is now expected to double.