He has been to China twice since August and plans three trips this year, partly in hopes of finding new ventures that address the country’s voracious need for energy.

“They’re going to require a greater increase in electricity than anywhere else,” Mr. Rockwell said.

He said that China was already beginning to look more intensely at renewable sources, like wind, hydro and solar. “It’s going to create a lot of opportunities.”

John Denniston, a partner at Kleiner, Perkins, Caufield & Byers, said he heard a similar message when he met with a high-ranking official in the Ministry of Science and Technology.

The deputy minister told him that “one of their highest goals is to find alternative energy sources that decrease their dependence on oil,” Mr. Denniston said. And he said that in conversations with other officials, entrepreneurs and scientists, “everyone was on the same playbook.”

Mr. Denniston has not made any investments yet, but is interested in exploring opportunities. He said he was curious to see if China, because of its high demand for energy, could leapfrog some other countries and become a leader in alternative solutions, like being the first to mandate all-electric vehicles.

Mr. Rockwell agrees that China has a chance to define itself early-on as promoting alternatives to oil: “When you don’t have an established grid, a lot of renewables look more attractive.”

A perhaps more basic issue that investors say is challenging China is the simple demand for enough potable water and clean food — industries that fall under the loose and broad definition of “cleantech.”