PORTSMOUTH, N.H. (AP) – Presidential hopeful Bill Richardson traipsed up a mountain of wood chips and called for increased investment in alternate energy sources, such as the wood-burning power plant he toured Sunday.

The Democratic New Mexico governor and former energy secretary said Public Service Company of New Hampshire’s Schiller plant could be a model for future investments and could help reduce reliance on fossil fuels.

“It shows if we’re ingenious, we can have renewable fuel and renewable energy as the main source for the future,” he said, wood chips still clinging to his navy blazer. “Even if it means government subsidies, I would be supportive of that.”

During his hour-long tour, Richardson cut off his tour guides with more questions: What is stopping others from converting their coal-burning plants into wood-burning? What is the environmental impact of the vapors blowing from the stacks on the river bank? Are they making money?

Even when pushing a button to unload tons of wood chips from a tractor-trailer, Richardson kept peppering his hosts.

“So all you need is tax breaks and incentives?” he asked.

PSNH converted one of its three coal-burning furnaces to wood-powered last year. Each day, the plant burns through about 1,500 tons of the lumber refuse. The timber industry has praised the operation as a way for foresters to make use of the scraggly, unusable trees; conservationists say the plant helps gird against clearcutting.

Later Sunday, Richardson visited Rockingham County Democrats’ clambake and told them their party should be the party of science and technology.

“I would make America the leader on global climate change,” Richardson said. “We’ve got to find ways to be more energy independent. … It’s not going to be coal. It’s not going to be natural gas. It’s going to be renewable energy resources.”

He also touted his international credentials and said “our obsession with Iraq” has distracted the United States from anti-nuclear proliferation and human rights.

He repeated his pledge to close the U.S. prisons at Guantanamo Bay, Cuba, and improve U.S. public schools.

He also lamented the increasingly crowded primary schedule but pledged to support New Hampshire’s first-in-the-nation status.

“Here’s our strategy: We compete whenever New Hampshire wants us to compete,” said Richardson, who trails in most polls. “Just don’t have the primary in July. Let me build up a little speed.”