As the rest of the United States celebrated Labor Day last September, Doug Durst was working with four Chinese researchers as they monitored 48 tubes filled with algae in a mobile laboratory in Kentucky.

A solar and wind-powered street lamp, developed by Urban Green Energy, helps light the streets of San Francisco. The company has also made street lamps in Sanya, Hainan province. [China Daily]

As a strategic planning manager for Duke Energy Corp, he was working with experts from China's ENN Group on a three-month mission to find the best strain for soaking up carbon emissions at coal-fired power plants.

"Wang Huiling treated the algae as if it were her babies," Durst said of the only female scientist in the group.

The project not only highlights one of several partnerships between Duke Energy, the largest utility company in the US, ENN and China's Huaneng Group, but also represents the many examples in which Chinese and US businesses, government agencies and NGOs are teaming up to explore clean-energy technologies and policies.

Whether they are small, family-run, or multinational giants, joint efforts are blazing new trails in sustainable development and green industries.

China and the US together account for more than 40 percent of the world's greenhouse gas emissions, and that means both nations have "a lot of responsibility," said David G. Hawkins, director of climate programs for the Natural Resources Defense Council, a US environmental action group with 1.3 million members and online activists.

"It also means there is a tremendous opportunity if we cooperate and make this a strategic objective of our relationship. We have a lot of power to improve the situation," said Hawkins, whose group benefits from the expertise of more than 350 lawyers, scientists and other professionals.

The Duke-ENN algae experiment is one of several projects exploring new technologies.

Although algae are short-lived, scientists discovered they grow very fast, especially when feeding on carbon dioxide (CO2). As a result, researchers worldwide are experimenting with algae to reduce CO2 emissions at coal-fired power plants.

Back in China, ENN's scientists had begun testing for algae strains with the best carbon-absorbent capability at a new research base in Langfang, Hebei province. They used pure CO2, which adds to the cost of algae cultivation, said Durst at Duke.

The tests in Kentucky went a step further, using flue gas from East Bend Station, a coal-fired power plant in Kentucky, as the CO2 nutrient source. After being fed the gas, the algae turned from light to dark green. It was then tested for carbon content.

The team of scientists, who worked almost seven days a week for the entire three months, found several strains that grew just as well using flue gas rather than pure CO2.

Duke "benefited from the three years of intensive research ENN conducted at its eco-city facility (in Langfang)", said Durst. "In that integrated and controlled environment, the Chinese biochemists tested hundreds of strains of algae and identified the ones they believed work best with flue gas."