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By David Adams
MIAMI, Sept 2 (Reuters) - When Charlie Crist last governed Florida, his green energy and climate policies made him few friends among the state's powerful electricity corporations.
Now, as the Republican-turned Democrat bids to return to the governor's mansion, it may be payback time.
Florida's three largest utilities have poured money into the re-election campaign of Republican incumbent Governor Rick Scott in an expensive and closely watched political battle for the nation's largest swing state.
The election spending is notable in a tight race where the issues of energy and climate change have taken center stage in recent weeks, with both candidates asserting their environmental credentials.
As Republican governor between 2007 and 2011, Crist "sent shivers through the entire utility system," said Colleen Castille, who headed the Florida Department of Environmental Protection under Governor Jeb Bush.
Crist was a darling of clean energy advocates, hosting a climate change summit in 2007 alongside another green Republican, California Governor Arnold Schwarzenegger. His focus on clean energy challenged the Florida utilities who are heavily dependant on natural gas and coal, as well as some nuclear.
In his bid to return to the office he left in 2011 - to run unsuccessfully for the U.S. Senate - he has yet to outline his energy policy, but utilities aren't taking any chances.
According to current state records, Florida Power & Light , the state's largest electric utility serving 4.6 million customers, over the last year has given a combined $1.2 million to Scott's political action committee, Let's Get to Work, and the Republican Party of Florida. Duke Energy contributed another $1.2 million to Scott and the Republican Party.
A third company, TECO, contributed $1.15 million to the Republican Party of Florida.
Crist's campaign does not appear to have received a penny from the utilities, though they have contributed a combined $500,000 to the Florida Democratic party.
"The big utilities aren't fans of his because as governor and Attorney General, Charlie Crist actually stood up to them and fought to keep families' rates low," the Crist campaign said in an emailed statement.
"Rick Scott has taken millions of dollars from them and let them hike Floridians' energy bills and stifle the development of renewable energy."
Earlier in his career, Crist was the beneficiary of the largesse of power companies, who have increasingly favored Republicans over Democrats in recent years.
It's not easy to precisely calculate the effect of the utilities' contributions on the 2014 governors' race as funds can be channeled in various forms through different entities.
A spokesman for FP&L, one of the largest rate-regulated utilities in the United States, declined to discuss the election race but pointed out that FP&L had made solar investments and in the past supported Crist's efforts to cut carbon emissions.
Duke Energy also declined to discuss contributions, but made clear its preference in the race. "We support Governor Rick Scott because we believe Governor Scott has a better plan for Florida," said a company spokesman.
A TECO spokeswoman confirmed its contribution to the Republican Party of Florida, adding, "We support candidates who focus on building the economy and creating jobs."
Both campaigns are brimming with money: Scott has hauled in about $28 million since November compared to $21 million for Crist.
While in office Scott has built a business-friendly reputation supporting utility rate hikes to cover massive investments in new power lines, natural gas pipelines and nuclear plants that environmentalists oppose.
Under Scott's watch the state's renewable energy programs, including solar installation rebates, were dismantled.
Scott denies his campaign is in bed with the utilities, saying his policies have kept rates in check while limiting government meddling.
"Governor Scott is always looking at ways to diversify Florida's energy sources, but unlike Charlie Crist, he does not believe that Floridians should pay higher energy costs due to overly burdensome government regulations," said Scott's spokesman, Greg Blair.
California billionaire Tom Steyer, a former hedge-fund manager turned environmental advocate, in August began targeting Scott's environmental record, as well as the political contributions the governor has received from the utilities.
Steyer's Super-Pac, NextGen Climate, has run ads highlighting the Scott administration's approval of a plan to let Duke Energy continue billing consumers for $3.2 billion in higher electric rates to pay for two failed power plants.
Scott hit back with his own barrage of ads, accusing Steyer and Crist of inventing "fiction," noting that Crist backed nuclear expansion as governor.
In one ad the Scott campaign agreed that Duke got a soft deal, but blamed it on Crist. "Crist made it easier for Duke Energy to take your money," the campaign said.
In March the non-partisan watchdog, Integrity Florida, published a report critical of the political influence of Florida's top energy corporations.
"Increasingly, the Florida Legislature sets its agenda and policy outcomes based on the needs of large political donors rather than the public interest," it concluded. "For the last five election cycles, these electric utilities were among the largest donors to state-level campaigns in Florida."
Electric utilities contributed more than $18 million to state-level candidates and party organizations between 2004 and 2012, two-thirds of which went to Republicans, it said.
During that period legislators approved higher consumer electricity prices while removing consumer-friendly state regulators who opposed the rate hikes, the report found. (Additional reporting by Bill Cotterell in Tallahassee and Letitia Stein in Tampa, editing by Ross Colvin and John Pickering)