Apple is stepping up its green energy efforts in China in a bid to reduce the air pollution attributed to the manufacture of its devices.
The company is working with its Chinese suppliers to eventually produce 2.2 gigawatts of solar power and energy from other renewable sources.
Apple estimates that 20 million tonnes of greenhouse gas pollution will be avoided, equivalent to four million cars, as more of its suppliers rely on renewable energy between now and 2020.
Panels capable of generating about 200 megawatts of solar power will be financed in the northern, southern and eastern regions of China, where many of the technology company’s suppliers are located.
The remaining two gigawatts of renewable energy will be achieved through deals with its Chinese suppliers to provide a mix of solar, wind and hydro-electric power.
Foxconn, which runs the factory where the most iPhones are assembled, is pledging to contribute 400 megawatts of solar power as part of the two-gigawatt commitment.
The solar panels, which will be built by 2018 in China's Henan province, are designed to produce as much renewable energy as Foxconn's Zhengzhou factory consumes while making iPhones.
Apple chief executive Tim Cook said: "Climate change is one of the great challenges of our time, and the time for action is now. The transition to a new green economy requires innovation, ambition and purpose."
Apple recently completed a number of projects in China that generate 40 megawatts of solar energy to offset the power required by its 24 stores and 19 offices in the country.
All of Apple's data centres, offices and stores in the US have already been running on renewable energy.
"When you look at all the air pollution in China, all the manufacturing that is done there has a lot to do with it, so this is a significant step in the right direction," said Gary Cook, a senior analyst for Greenpeace.
The company recently shifted 13 million of its new iPhone, the 6s, in just its first weekend on sale. It has reportedly launched a secret lab to begin development on self-driving electric cars in a move similar to its rival Google.