Apple said on Thursday it has nearly doubled the number of suppliers using only clean energy for production work, including two that assemble and make the processor chips for the iPhone.

Because of this partnership between Apple and its suppliers, Apple will exceed its goal of bringing 4 gigawatts of renewable energy into its supply chain by 2020, with over an additional gigawatt projected within that timeframe. This comes one year after Apple announced that all of its global facilities are powered by 100 percent renewable energy.

To address emissions from manufacturing products, Apple and its suppliers have invested in or procured a mix of clean energy technology, including wind and solar.

Apple reduced its comprehensive carbon footprint for the third year in a row in 2018, in large part due to the company’s Supplier Clean Energy Program. Manufacturing makes up 74 percent of Apple’s carbon footprint, so the program helps its suppliers increase energy efficiency and transition to renewable energy sources. Last year, Apple and its suppliers participated in clean energy generation that roughly equaled the electricity needed to power over 600,000 homes in the US.

Apple also launched a fund with 10 of its suppliers last year to help finance renewable energy projects in China.

The company also announced progress to address environmental solutions by allocating all $2.5 billion in green bonds it previously announced, the largest of any US corporation. Through its now-completed $2.5 billion Green Bond allocations, the company has contributed to 40 environmental initiatives around the world. That includes projects Apple has created to cover its entire electricity load — as of January 2019, approximately 66 percent of the renewable energy Apple uses comes from such endeavors.

Forty-four companies are now in Apple's Clean Energy program, including Hon Hai Precision Industry Co Ltd, whose Foxconn unit makes iPhones, and Taiwan Semiconductor Manufacturing Co Ltd, which supplies the A-series chips that power all of Apple’s mobile devices.

The list of newly committed suppliers includes: Advanced International Multitech, Arkema, AT&S, Bemis Associates, Biel Crystal (HK) Manufactory Ltd., BOE, Catcher Technology, Compal Electronics, Corning Incorporated, COSMO, DSM Engineering Plastics, ECCO Leather, Fastway Creation, Finisar, Goertek, Golden Arrow, H.B. Fuller, Hon Hai Precision Industry, Ibiden, Jabil, LEALEA Enterprise, Lens Technology, Lishen, Luxshare-ICT, Mega Precision, Nidec, Pegatron, Primax Group, Qorvo, Quadrant, Quanta Computer, RRD, RyPax, SanHuan, SDK, Solvay, STMicroelectronics, Sunway Communication, Sunwoda Electronics, Taiyo Ink Mfg. Co., tesa SE, TSMC, Wistron and Yuto.