The environmental group Greenpeace says China's three largest power companies created more greenhouse gas emissions last year than the entire United Kingdom.
In a new report, Greenpeace says China's reliance on coal is hurting Beijing's fight against global warming.
Greenpeace recommends a new tax on coal for power companies.
It also calls on China to double its renewable energy goal so that by 2020, 30 percent of its power comes from solar and wind.
With its burgeoning economy and growing demand for cars, China has rapidly become one of the world's biggest polluters.
Chinese officials have said they are working to cut greenhouse gas emissions.
The three Chinese companies named by Greenpeace are China Huaneng Group, China Datang Corporation and China Guodian Corporation.
Some information for this report was provided by AFP, AP and Reuters.