Power plants and industrial facilities that emit carbon dioxide are hopeful that Congress will keep tax credits for capturing the gas and storing it deep underground. The process, called carbon capture and sequestration, is seen by many as an important way to reduce pollution during a transition to renewable energy. But it faces criticism from some conservatives, who say it is expensive and unnecessary, and from environmentalists, who say it has consistently failed to capture as much pollution. …The most commonly used technology allows facilities to capture and store around 60% of their CO2 emissions during the production process. Anything above that rate is much more difficult and expensive, according to the IEA. …Even so, carbon capture is an important tool to reduce CO2 emissions, particularly in heavy industries, said Sangeet Nepal at the Carbon Capture Coalition. “It’s not a substitution for renewables … it’s just a complementary technology”.