“Clean technology is the next wave of innovation that Silicon Valley needs to capture,” the mayor said, noting that the San Jose City Council had committed to increasing the number of “green jobs” in the city to 25,000 by 2022. San Jose currently has 4,350 such jobs, according to city officials.

But SolFocus assembles its solar panels in China, and the new San Jose headquarters employs just 90 people.

In the Bay Area as in much of the country, the green economy is not proving to be the job-creation engine that many politicians envisioned. President Obama once pledged to create five million green jobs over 10 years. Gov. Jerry Brown promised 500,000 clean-technology jobs statewide by the end of the decade. But the results so far suggest such numbers are a pipe dream.

“I won’t say I’m not frustrated,” said Van Jones, an Oakland activist who served briefly as Mr. Obama’s green-jobs czar before resigning under fire after conservative critics said he had signed a petition accusing the Bush administration of deliberately allowing the Sept. 11 terrorist attacks, a claim Mr. Jones denies.

A study released in July by the non-partisan Brookings Institution found clean-technology jobs accounted for just 2 percent of employment nationwide and only slightly more — 2.2 percent — in Silicon Valley. Rather than adding jobs, the study found, the sector actually lost 492 positions from 2003 to 2010 in the South Bay, where the unemployment rate in June was 10.5 percent.

Federal and state efforts to stimulate creation of green jobs have largely failed, government records show. Two years after it was awarded $186 million in federal stimulus money to weatherize drafty homes, California has spent only a little over half that sum and has so far created the equivalent of just 538 full-time jobs in the last quarter, according to the State Department of Community Services and Development.

The weatherization program was initially delayed for seven months while the federal Department of Labor determined prevailing wage standards for the industry. Even after that issue was resolved, the program never really caught on as homeowners balked at the upfront costs.

“Companies and public policy officials really overestimated how much consumers care about energy efficiency,” said Sheeraz Haji, chief executive of the Cleantech Group, a market research firm. “People care about their wallet and the comfort of their home, but it’s not a sexy thing.”

Job training programs intended for the clean economy have also failed to generate big numbers. The Economic Development Department in California reports that $59 million in state, federal and private money dedicated to green jobs training and apprenticeship has led to only 719 job placements — the equivalent of an $82,000 subsidy for each one.

“The demand’s just not there to take this to scale,” said Fred Lucero, project manager atRichmond BUILD, which teaches students the basics of carpentry and electrical work in addition to specifically “green” trades like solar installation.

Richmond BUILD has found jobs for 159 of the 221 students who have entered its clean-energy program — but only 35 graduates are employed with solar and energy efficiency companies, with the balance doing more traditional building trades work. Mr. Lucero said he considered each placement a success because his primary mission was to steer residents of the city’s most violent neighborhoods  away from a life of crime.

At Asian Neighborhood Design, a 38-year old nonprofit in the South of Market neighborhood of San Francisco, training programs for green construction jobs have remained small because the number of available jobs is small. The group accepted just 16 of 200 applicants for the most recent 14-week cycle, making it harder to get into than the University of California. The group’s training director, Jamie Brewster, said he was able to find jobs for 10 trainees within two weeks of their completing the program.

Mr. Brewster said huge job losses in construction had made it nearly impossible to place large numbers of young people in the trades. Because green construction is a large component of the green economy, the moribund housing market and associated weakness in all types of building are clearly important factors in explaining the weak creation of green jobs.

Advocates and entrepreneurs also blame Washington for the slow growth. Mr. Jones cited the failure of so-called cap and trade legislation, which would have cut carbon pollution and increased the cost of using fossil fuel, making alternative energy more competitive. Congressional Republicans have staunchly opposed cap-and-trade.

Mr. Haji of the Cleantech Group agrees. “Having a market mechanism that helps drive these new technologies would have made a significant difference,” he said. “Without that, the industry muddles along.”

Still, California has forged ahead with environmental legislation, including its own version of cap-and-trade that is part of the landmark anti-global-warming law AB 32 enacted in 2006. Another measure, signed into law earlier this year by Mr. Brown, requires utilities to generate at least a third of all their electricity from renewable sources by 2020.

State government officials said they were still banking on these new laws to propel demand for 20,000 megawatts of renewable energy, the cornerstone of Mr. Brown’s green jobs plan. In June, the governor attended the groundbreaking of the 3,470-megawatt Blythe Solar Power Project in the Mojave Desert, which backers say will create 5,390 construction jobs and 400 permanent positions.

The 600-turbine Alta Wind Energy Center southeast of Bakersfield is set to become the world’s largest wind farm when it is completed in 2015. Terra-Gen, a company based in New York that has received more than $300 million in private investment from Google and Citi for the Alta farm, says it will bring 1,020 megawatts on line by the end of the year. But even when it is fully up and running, the wind farm will bring only 50 permanent operations and maintenance jobs to rural Kern County, the company said.

Both the possibilities and limitations of the green economy were on display at SolFocus’s ribbon-cutting in San Jose.

A SolFocus spokeswoman, Nancy Hartsoch, said the company was willing to pay a premium for the highly-skilled physicists, chemists and mechanical engineers who will work at the campus on Zanker Road, although the solar panels themselves will continue being made in China. Mayor Reed said he continued to hope that San Jose would attract manufacturing and assembly jobs, but Ms. Hartsoch said that was unlikely because “taxes and labor rates” were too high to merit investment in a factory in Northern California.

SolFocus’s plans do not much resemble what Mr. Jones, the former Obama administration official, had in mind in his 2008 book, “The Green Collar Economy: How One Solution Can Fix Our Two Biggest Problems,” when he described the green economy as “Joe Sixpack with a hard hat and a lunch bucket going off to fix America,” and talked of millions of new jobs.

In an interview last week, though, he seemed to have scaled back. “The green economy as we initially conceived it,” Mr. Jones said, “was never supposed to save the entire global economy.”