A bill to boost sun, wind and other alternative energy sources is steamrolling to the governor's desk despite efforts Thursday to add water-storage projects to the legislation.

"I'm concerned that we are hastily jumping on a runaway train, simply because this issue polls well," Senate Minority Leader Andy McElhany, R-Colorado Springs, said. "If the marketplace supports more expensive energy sources, it should get there without government mandates."

The bill would double the renewable energy standard required under Amendment 37, which was passed by voters in 2004. It would require large utilities to get 20 percent of their power from renewable sources by 2020.

It also would establish a standard for rural utilities serving fewer than 40,000 customers. They would be required to get 10 percent of their electricity from renewable sources by 2020.

Democrats called the measure a significant step in positioning Colorado to become a leader in renewable energy development and production.

The Senate, with the help of a handful of Republicans, initially passed House Bill 1281 on a voice vote. It is expected to give its final approval today.

Democrats rejected attempts by some Republicans to amend the measure to boost the development of hydroelectric projects with an aim of building more dams to bolster the state's water-storage capacity.

"We're not in a state where we can dam rivers to create large hydro projects," said Sen. Gail Schwartz, D-Snowmass Village, the bill's sponsor. "We have an opportunity here to invest in a new energy such as wind and solar . . . to build a new energy economy in Colorado. Hydro is a clear option in this bill, but fostered in a responsible manner."

The bill limits new hydroelectric sources to 10 megawatts or less, and existing hydro plants to 30 megawatts. Currently, 15 dams in Colorado produce hydroelectricity.

Sen. Ted Harvey, R-Highlands Ranch, tried to amend the bill to raise the overall cap to 30 megawatts.

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