BEIJING  When the United States’ top energy and commerce officials arrive in China on Tuesday, they will land in the middle of a building storm over China’s protectionist tactics to become the world’s leader in renewable energy.

Calling renewable energy a strategic industry, China is trying hard to make sure that its companies dominate globally. Just as Japan and South Korea made it hard for Detroit automakers to compete in those countries  giving their own automakers time to amass economies of scale in sheltered domestic markets  China is shielding its clean energy sector while it grows to a point where it can take on the world.

Steven Chu, the American energy secretary, and Gary Locke, the commerce secretary, are coming here to discuss clean energy and global warming with Chinese leaders, and to see if progress can be made toward getting China to agree to specific targets for reductions in greenhouse gases. Agreement proved elusive during the Group of 8 summit meeting last week in Italy.

But Mr. Chu and Mr. Locke arrive as Western companies, especially Europeans, are complaining increasingly about Beijing’s green protectionism.