A new study says that the number of green jobs in the United States grew 9.1 percent between 1998 and 2007, about two and a half times faster than job growth in the economy as a whole.

The study, from the Pew Charitable Trusts, also breaks down green job growth on a state-by-state basis.

Green jobs are defined here as those belonging to the “clean energy economy,” which the study calls one that “generates jobs, businesses and investments while expanding clean energy production, increasing energy efficiency, reducing greenhouse-gas emissions, waste and pollution, and conserving water and other natural resources.”

Unsurprisingly, California has the most green jobs — more than 125,000 — followed by Texas at over 55,000. Oregon is the only state where green jobs represented more than 1 percent of employment.

Idaho led the way in green job growth, with 126 percent more such jobs over that time period, followed by Nebraska at 109 percent. New Mexico, Oregon and Kansas all posted just above 50 percent green-job growth.

Nine states — including New York and New Jersey — saw the number of green jobs decline from 1998 to 2007, with the largest loss (albeit from a small base) coming in Utah.

A number of states — Connecticut, Indiana, Massachusetts, Michigan, Nebraska and Ohio, as well as the District of Columbia — experienced job losses in the overall economy from 1998 to 2007, but added green jobs.

Over all, some 770,000 jobs in the nation are tied to the clean energy economy, the Pew researchers found — and they predicted more growth in the sector. By way of comparison, the “fossil fuel sector” of utilities, coal mining and oil and gas extraction accounted for 1.27 million jobs in 2007, the study said.

The study also discusses clean technology patents. The lion’s share — nearly 47 percent — of the clean-tech patents registered between 1999 and 2008 have been for batteries (although the number of battery patents is falling). The next largest share was fuel cells at 25.6 percent. Solar accounted for 8.7 percent of total clean-tech patents.

Other studies have forecast green job growth potential as the Obama administration promotes alternative energy sources.