Italian oil major Eni, which has historically invested little in renewable energy given its success in discovering oil and gas, plans renewable energy projects in Italy, Pakistan and Egypt.
As part of a push into green energy, Eni aims to bring 420 megawatts of mostly solar power generation online by 2022 by reusing derelict land linked to existing fossil fuel operations.
Chief Executive Claudio Descalzi expects Eni to invest 1 billion euros ($1.1 billion) over the next three years in renewable energy projects and research.
The world is currently adding more clean energy capacity than coal, oil and gas combined and Eni joins other oil majors in turning to green energy investments to curb carbon emissions and get a foothold in the fast growing sector.
Last year, Europe's top oil firms urged governments around the world to introduce a pricing system for carbon emissions as part of a wider push to move to a low-carbon economy.
French oil company Total said this week it was buying high-tech battery maker Saft as its seeks to expand its renewable energy business.
"In the next three years investments in renewable projects will be around 500 million euros with a similar amount for scientific research," Descalzi said at the Eni annual shareholder meeting on Thursday.
The state-controlled oil major has already spent 500 million euros on solar energy projects over the last three years.
In Italy alone, Eni said it expects to build more than 220 megawatts of solar power capacity in regions including Liguria, Sardinia, Sicily, Calabria, Puglia and Basilicata for an estimated 200 to 250 million euros.
Eni's existing gas-fired plants will be used in tandem with solar to cover any shortfalls when the sun doesn't shine.
But Descalzi ruled out any idea of competition with Italy's leading renewable energy company Enel.
"Our model is not greenfield... (The projects) will be based on our land, with contracts signed by us on existing contracts," the CEO said.
Oil and gas remain at the heart of Eni's investment plans. Last month Descalzi outlined plans to invest 20 billion euros in Africa over the next four years, mostly in oil and gas, while also boosting the continent's energy mix by spending on renewables.
Eni previously said it was ready to spend "hundreds of millions" of euros on solar power projects in Africa, where it is the largest foreign oil and gas producer.