Amazon has announced plans to install solar arrays that can produce up to 20 megawatts of power at its fulfilment centres around the UK.

Amazon said it expected the panels to “generate the equivalent amount of electricity required to power over 4,500 U.K. homes.” Additionally, they will cut the company’s carbon footprint by 6,000 tonnes of carbon dioxide per year.

According to the company it plans to deploy large scale rooftop solar panels at 10 fulfilment centres over the next 18 months. This is subject to planning and landlord approval.

“As our fulfillment network continues to expand, we want to help generate more renewable energy at both existing and new facilities around the world in partnership with community and business leaders,” Stefano Perego, Amazon U.K.’s operations director, said in a statement.

“We are putting our scale and inventive culture to work on sustainability, which is good for the environment, our business, our customers, and the communities in which we operate,” Perego added. “By diversifying our energy portfolio, we can keep business costs low and pass along further savings to customers.”

Amazon has also said that it has signed a deal that means all of its UK buildings are powered with 100% renewable energy.

This electricity will be backed by Renewable Energy Guarantee of Origin certificates, which means that the energy bought for fulfilment centres and other buildings will have come from sources such as wind and solar.