UPDATE 1-Enbridge expanding Sarnia solar-power project

* Enbridge boosting solar plant to 80 megawatts

* First Solar to build, maintain project

* Enbridge shares rise 0.6 percent

CALGARY, Alberta, Dec 8 (Reuters) - Enbridge Inc (ENB.TO), said on Tuesday it is quadrupling the size of its Sarnia, Ontario, solar-power facility, spending C$300 million ($288 million) to increase its capacity to 80 megawatts and expanding its push into green power.

Enbridge, Canada's No. 2 pipeline company, said the investment would make the Sarnia site North America's largest solar plant, producing enough electricity to power 12,800 homes and saving 39,000 tonnes of carbon-dioxide emissions a year.

In October, Enbridge bought the Sarnia project in southern Ontario from developer First Solar Inc (FSLR.O), one of the world's largest producers of the photovoltaic cells that convert sunlight into electricity. The first 20 megawatt phase of the project entered commercial service on Monday.

Enbridge is best known as the operator of North America's largest crude oil pipeline network and ships the lion's share of Canada's oil exports to the United States on its lines.

But the company has been making a push into the renewable energy business, operating four wind-power projects, with a fifth, 99-megawatt project slated to be completed next December.

The solar expansion is also expected to be complete by December 2010.

"With this investment, we will have interests in more than 470 megawatts of green power capacity from our five wind energy projects, expanded solar facilities, four waste heat recovery facilities and the world's first commercial application of hybrid-fuel cell technology," Pat Daniel, Enbridge's chief executive, said in a statement.

First Solar will build and maintain the Sarnia project and Enbridge has a 20-year agreement to sell the power to the Ontario Power Authority.

Enbridge shares rose 29 Canadian cents to C$46.88 on Tuesday morning on the Toronto Stock Exchange.

($1=$1.06 Canadian) (Reporting by Scott Haggett; editing by Rob Wilson)