TAMPA — Since its acquisition by Canada's Emera Inc. in 2016, Tampa Electric Co. has started investing more heavily in renewable energy.
Under Emera, the Tampa-based utility announced it was investing in 600 megawatts of solar power, putting it on track to generate more electricity from the sun than any of the major Florida investor-owned utilities. Its plan to convert part of the Big Bend Power Station in Apollo Beach to natural gas also will cut its use of coal in half.
"It's all part of our plan to become cleaner and greener," said Cherie Jacobs, Tampa Electric spokeswoman. "We are systematically moving away from coal, (and) we're committed to renewables."
But environmental scientists and advocates say the utility isn't moving quickly enough toward renewable energy. Instead, they say, Tampa Electric's increasing dependence on natural gas means it will be wedded to a major source of greenhouse gas emissions that, while cleaner than coal, significantly contribute to climate change.
And while it is outpacing its Florida peers with its investment in solar energy, Tampa Electric still will overwhelmingly rely on fossil fuels to keep the lights on and air conditioners humming for years.
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Much of the criticism leveled at Tampa Electric stems from the utility's ongoing effort to convert one of its four generators at Big Bend to natural gas.
Currently, Big Bend's generators run primarily on coal. Tampa Electric announced in 2018 that it would convert one of the coal-fired generators — Unit 1 — to a combined-cycle natural gas generator by 2023. By 2021, it will retire another coal-fired generator — Unit 2 — the same one where an accident killed five workers in 2017.
When completed, the renovated generator will produce 1,090 megawatts of power, 294 megawatts more than the coal generators it is replacing. The remaining two generators will continue to be powered primarily by coal, with secondary capabilities to run on natural gas, but Tampa Electric has no current plans for full conversion.
Tampa Electric, like many utilities, was drawn to natural gas because of its low cost and around-the-clock reliability, Jacobs said.
"Fracking has changed the game in terms of how inexpensive it is to extract gas and get it to power plants," said Mark Dyson, principal in the electricity program at nonpartisan research group the Rocky Mountain Institute. "Utilities are making a bet that will remain the case for the foreseeable future."
Even in the recent past, natural gas prices have proved to be somewhat volatile. Last week, state utility regulators at the Florida Public Service Commission granted Tampa Electric a rate increase of $4.05 on customers' average monthly bills to account for higher-than-expected natural gas prices. The increase will take effect in April.
And then there's the environmental impact.
Tampa Electric's Jacobs said switching from coal to natural gas will "improve the land, air and water" around the plant, as it will cut emissions by half compared to the coal generators.
But Harold Wanless, professor and chair of the University of Miami's geological sciences department, warned that natural gas won't improve all that much.
"Coal is worse than oil, and oil is worse than (natural) gas, but they all produce a major amount of carbon dioxide per unit of energy created," he said.
Emissions at the plant aren't the only thing to worry about. Drilling for and extracting natural gas releases methane, which according to the Environmental Protection Agency, is far more potent than carbon dioxide in trapping heat radiating into the atmosphere.
"If you account for leakage estimates" from extraction and during transportation, Rocky Mountain Institute's Dyson said, "from the academic literature, burning natural gas is just about as bad as coal."
Environmental advocates such as the Sierra Club have pushed back against Tampa Electric's project heavily based on these points.
"Fossil fuels are not clean. Period," said Susannah Randolph, senior campaign representative for the club's "Beyond Coal" effort in Florida.
All three major Florida utilities have taken major steps toward using more natural gas in recent years in the name of efficiency and cost — Tampa Electric's Big Bend project, Duke's newly-finished combined-cycle natural gas plant in Citrus County and its stake in the Sabal Trail Transmission Pipeline, and Florida Power & Light's plan to build a 1,200-megawatt natural gas plant by 2022.
But not all utilities are moving to natural gas the way Florida is. Others around the country are eschewing natural gas in favor of renewables.
Colorado's largest utility, Xcel Energy, filed last June to replace two of its coal generators with renewable sources. Arizona's utility regulators put a nine-month ban on building new natural gas plants that were larger than 150 megawatts and pushed utilities to come up with plans that rely more heavily on renewables and energy storage. California, too, paused plans for a natural gas plant in the city of Glendale last year, and for another in Ventura County in 2017.
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When the Big Bend project is complete, Tampa Electric will generate 75 percent of its energy from natural gas, 12 percent from coal and 7 percent from solar, even after its installation of new solar panels. Another 6 percent will come from sources such as oil. Its mix just two years ago was 69 percent natural gas, 24 percent coal and 6.5 percent "other," which included solar and oil.
By comparison, Duke Energy Florida, the other major utility in Tampa Bay, generates just 0.1 percent of its energy from solar, 77 percent from natural gas, 23 percent from coal and 0.2 percent from oil according to spokeswoman Ana Gibbs. It is currently seeking to build 700 megawatts of solar by 2022.
As of 2018, Florida Power & Light generated 72 percent of its electricity from natural gas, 22 percent from nuclear, 1.5 percent from purchased power, 3.6 percent from coal, 1.5 from solar and 0.3 percent from oil.
While Tampa Electric outpaces its Florida peers in terms of renewable generation, it lags Emera's other major utility, Nova Scotia Power in Canada. It's on track to get 41 percent of its power from renewables by 2020, according to company projections. Jacobs, Tampa Electric's spokeswoman, said that is partially because of the availability of hydropower in Canada that she said is not as readily available in Florida.
Such a heavy reliance on natural gas may not be cost effective in the long run. According to a 2018 study by the Rocky Mountain Institute on the economics of different energy sources, renewables today "already outcompete" natural gas projects and "threaten to erode their revenue within the next 10 years."
The analysis included a case study of an unnamed Florida utility's plan for a new 1,200-megawatt combined cycle natural gas plant that will be complete by 2022, which mirrors Florida Power & Light's plan. If that utility had opted for clean energy alternatives instead of building a natural gas plant from scratch, the study said, it would have cost 6 percent more up front, but would have been less expensive down the line because of the cost of maintaining the plant.
It would also save 66 million tons of carbon dioxide emissions over the life of the plant.
"Natural gas is a bridge fuel," Dyson said. "But today that bridge leads backward."
Contact Malena Carollo at email@example.com or (727) 892-2249. Follow @malenacarollo.