On Wednesday, Apple announced that 175 of its suppliers have committed to using clean energy in their work for the iPhone maker, bringing more than 9 gigatonnes of clean energy onto power grids.

The new suppliers, which are an increase from the 70 suppliers and approximately 8 gigatonnes of power reported last year, are part of the company’s efforts to make its vast global supply chain carbon-neutral by 2030.

The companies must commit to using renewable energy sources such as solar or wind energy for Apple work, as part of the tech company’s efforts announced last year to have its products have a “net-zero” climate impact.

SK Hynix of South Korea is one of the suppliers, supplying memory chips for Apple devices and being one of the first Korean firms to join Apple’s program.

STMicroelectronics, a top supplier of sensors and other chips in iPhones, will also participate. Since committing to the program, Apple has said that STMicroelectronics has started nine new renewable energy projects.

Apple now has 24 suppliers on the program, including India, Japan, and South Korea.

“One of the things that comes with this is the development of a core of businesses in different markets on different grids that demand clean energy.” That is beneficial to policymakers.” Lisa Jackson, Apple’s vice president of environment, policy and social initiatives, told Reuters.

Apple previously committed to clean energy pledges in 2019 with major suppliers such as Foxconn parent Hon Hai Precision Industry, which assembles many of its products, and Taiwan Semiconductor Manufacturing, which manufactures Apple’s processor chips.

The tech company also announced that it would fund ten smaller renewable energy projects aimed at bringing renewable energy to underserved communities.

Work on the projects includes collaboration with communities in South Africa, the Philippines, Colombia, and the Oceti Sakowin Power Authority, which was formed by six Sioux tribes in the western United States.