President-elect Donald Trump may question the need to use more renewable power, but a growing number of Internet companies don’t.

A report issued Tuesday by the Greenpeace environmental group finds that many of the world’s largest Internet companies — including Apple, Facebook and Google — have made major progress powering their online operations with renewable energy.

Almost 20 have committed to running their data centers and other facilities on 100 percent renewable energy as a way to fight global warming, although they differ on timetables and details.

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Yet other companies are opening energy-hungry data centers in states and countries that still derive most of their electricity from coal-fired power plants, which release more greenhouse gases than plants burning natural gas. And China’s fast-growing Internet titans — such as Alibaba and Baidu — generally don’t say where they get their electricity, according to Greenpeace.

“On the positive side, you see a race going on to build a renewable-powered Internet,” said Gary Cook, a Greenpeace analyst and lead author of the report.

“We see a lot of renewable energy deals, showing those companies are following through on their commitments — and that’s great,” he said. “On the flip side, we still see pretty poor transparency from a lot of companies.”

When Greenpeace first began studying the energy sources used by Internet companies, in 2009, none had yet publicly committed to 100 percent renewable power, he said.

Now, in 2017, Google plans to buy as much renewable power as the company uses worldwide. Since Google operates in some countries where renewable power remains scarce, the company will buy more than it needs in places where it is plentiful and sell any excess electricity on the open market.

Information technology already consumes about 7 percent of the electricity generated around the world, according to the report. And that demand will grow as more of the Earth’s population goes online and video streaming services surge.

The report gives high marks to Facebook, Apple and Google, who have used their purchasing power to help create a renewable energy market that other Internet companies can tap.

Other big names in the industry, however, receive harsher scores.

The report, for example, takes to task Amazon Web Services, the world’s largest cloud-computing operation. The Amazon subsidiary has been adding data centers in places such as Virginia with little renewable power. And it doesn’t release enough information about its energy use and greenhouse gas emissions for outsiders to gauge the effectiveness of the steps it has taken to combat climate change, according to Greenpeace.

The report even refers to Amazon Web Services as “one of the single biggest obstacles” to transparency about renewable power use.

Amazon has adopted a goal of deriving 100 percent of its electricity from renewable sources, although it has not set a deadline to reach that mark. The company plans to hit 50 percent by the end of this year and in November announced plans to fund construction of five new solar power plants in Virginia.

Asked to comment on the report, an Amazon spokeswoman pointed to some of the company’s recent announcements on renewable power projects.

Other prominent tech companies receiving poor grades from Greenpeace include Netflix and Twitter. Neither responded to a request for comment from The Chronicle.

While Greenpeace hopes to prod more Internet companies into action, it also wants such leaders as Google, Apple and Facebook to advocate in public for renewable power policies once Trump takes office. Trump has pledged to revive the American coal industry and has stocked both his transition team and his cabinet picks with people who have questioned climate science or tried to block efforts to rein in greenhouse gases.

“The federal government in the U.S. is going to be at best agnostic about energy and possibly hostile to climate policy, so corporations really have to get more engaged and push,” Cook said. “Companies who have been leading and who have made these commitments need to speak up and say, ‘This is important to us.’”

David R. Baker is a San Francisco Chronicle staff writer. Email: dbaker@sfchronicle.com Twitter: @DavidBakerSF