MORGANTOWN, W.Va. -- A pro-industry group said Wednesday that if it's allowed to continue, shale-gas development in West Virginia could support more than 29,000 jobs by 2020, doubling to 58,000 by the year 2035.

The new report issued by the U.S. Chamber of Commerce's Institute for 21st Century Energy says the natural gas industry has already created more than 11,800 direct and indirect jobs in the state and generated about $283 million this year alone in tax revenue.

Those revenues could hit $884 million a year for state and local governments by 2020, the report says. In all, it predicts West Virginia could see more than $25 billion in shale-driven revenues between 2012 and 2035.

The report is the second part of a three-part study co-sponsored by the institute, which launched a campaign to promote gas drilling in July.

The Marcellus Shale field that underlies much of West Virginia is considered to be one of the richest natural gas reserves in the world. The industry is also paying increasing attention to the Utica Shale, even deeper underground.

Steve Roberts, president of the West Virginia Chamber of Commerce, said West Virginia has a "proud history'' of producing energy, and the new report shows the importance of building on the opportunity created by unconventional drilling technologies.

The additional revenue, he argues, could help the state make big investments in education, public safety and infrastructure such as roads and bridges.

Environmental and citizens' groups, however, have concerns about the possibility of groundwater contamination from hydraulic fracturing, the process that uses water and chemicals to break gas deposits free from the rock. They also worry about air pollution and damage to roads and streams, among other things.

In September, 10 of those groups renewed their 2010 call for a moratorium on new drilling, arguing the industry is not sufficiently regulated.

West Virginia has enacted an array of new rules, but the Sierra Club, Ohio Valley Environmental Coalition and other groups maintain they're inadequate protection for public health and the environment.

The Sierra Club was among several groups that issued their own jobs projections Wednesday. They say some 19,500 jobs could be created in West Virginia if the state's two biggest utilities, FirstEnergy and American Electric Power, were required to invest in programs to promote energy efficiency.

Consulting firm Optimal Energy says focusing on energy efficiency through 2016 would also save customers a total of $800 million over the life of the efficiency investments, or $550 million more than under the companies' current plans.

"Energy efficiency creates a win-win situation. It puts money back in the pockets of our citizens and it creates jobs,'' said Stacy Gloss of Energy Efficient West Virginia.

West Virginia lags the nation in energy-efficiency investments, the groups say. In its 2012 State Energy Efficiency Scorecard, the American Council for an Energy-Efficient Economy ranked West Virginia 49th out of 50 states and the District of Columbia.