By Valerie Volcovici

WASHINGTON (Reuters) - A conservative nonprofit group that lobbies Republicans to support clean energy policy will spend more than $1 million over the next few weeks to back 10 members of Congress running in the Nov. 8 elections, hoping to attract key swing voters such as millennials.

Citizens for Responsible Energy Solutions (CRES) is backing Republican House and Senate candidates who favor clean energy, even as Republican presidential nominee Donald Trump mocks wind energy and calls climate change a hoax.

Embracing a clean energy agenda can help Republicans win in close races by attracting key voters like millennials and women, and help broaden the Republican base, James Dozier, CRES executive director, told Reuters.

“The way I look at it is regardless of who is in the Oval Office, we need clean energy champions on the Hill," said Dozier, who added that Republicans have ceded the issue to Democrats.

“This is a ripe opportunity to reframe Republicans' engagement in energy debate,” said Dozier. “We see this as an issue the party can use to grow the tent with the next generation of voters, with female voters and Hispanics and African Americans.”

CRES kicked off its fall spending campaign last week with more than $200,000 in radio ad buys for Alaska Senator Lisa Murkowski and North Carolina Senator Richard Burr, who faces a close re-election race against challenger Deborah Ross.

The group will spend an additional $900,000 in support of other Republican candidates, including New Hampshire Senator Kelly Ayotte, who is neck-in-neck with Democratic Governor Maggie Hassan in her re-election bid, and Representative Joe Heck, who is running in the hotly contested race for the open Nevada Senate seat against Democrat Catherine Cortez Masto.

On the House side, CRES will spend money for ads and voter turnout efforts for representatives from Illinois, Virginia, Florida and New York.

CRES is not alone in backing Republicans who can help the party embrace clean energy policy and accept the science behind climate change.

Jay Faison, a North Carolina-based businessman, launched the $2 million Clear Path Action Fund to launch digital media campaigns for candidates, including Ayotte, who support clean energy in key swing states.

But these Republican efforts are dwarfed by spending from environmental PACs that are spending record amounts to back Democrats.

The League of Conservation Voters said it will spend a record $40 million this election cycle.

Other groups, including green activist billionaire Tom Steyer's NextGen and the Natural Resources Defense Council Action fund, have also announced tens of millions of dollars more in spending.

(Reporting By Valerie Volcovici; Editing by Cynthia Osterman)