Which power sources kept the lights on during the 2014 polar vortex? 

Source: Daniel Cusick, E&E reporter • Posted: Friday, January 9, 2015

Sustained wind can sharpen frigid winter temperatures like those being experienced this week across much of the United States. But it also spins turbines that deliver low-cost power to the electricity grid as tens of millions of homeowners push thermostats to warmer settings, according to a new analysis by the U.S. wind power industry.

Findings from the American Wind Energy Association show that during the January 2014 polar vortex event, which occurred one year ago this week, wind energy “provided large quantities of critical electricity supply when it was needed most, keeping the lights on and reducing the impact of [electricity] price spikes,” the trade group said in a white paper released yesterday.

The report, which focused on grid conditions in the PJM Interconnection territory last January, is based on an analysis of hourly grid data, fuel price information and a detailed representation of the characteristics of every power plant in the region, according to AWEA.

The analysis found that while energy markets experienced major disruption during the 2014 polar vortex due to the unexpected shutdown of power plants and a run-up in natural gas prices caused by supply shortages, abundant wind energy helped to moderate the disruption and keep electricity prices from skyrocketing further.

Michael Goggin, AWEA’s director of research, said in a Tuesday webinar that utilities that were able to tap wind energy resources during the 2014 cold snap saved their customers on the order of $1 billion that they would have paid in higher bills had the wind power not been available.

“Wind energy has tremendous value because the cost of wind is always the same, the fuel is always free, and you can guarantee that you won’t see shifts in fuel prices over the life of a wind project,” Goggin said. “No conventional power source available offers that kind of security.”

But wind power wasn’t the only electricity resource that helped keep the lights on a year ago.

Other generators stress need for diversity

Coal and nuclear plants also saw a surge in output as electricity prices soared more than 10 times higher than average across large swaths of the Midwest, East and South yesterday and Tuesday.

Groups representing traditional fossil utilities and the nuclear industry have argued that the provision for stable, baseload power during periods of spiking demand and other market disruptions is equally important to protecting electricity consumers from outages and price spikes caused by severe weather.

Thomas Kuhn, president of the Edison Electric Institute, told Bloomberg News last March that the polar vortex provided a case study in why policymakers should advocate for policies that encourage fuel diversity, including coal and nuclear power.

study issued last summer by the consulting group IHS cautioned that a loss of fuel diversity in the electricity mix could exacerbate market disruptions like the one that occurred during the 2014 polar vortex.

Among other things, IHS determined that oil-fired power plants, which accounted for less than 1 percent of all generation in the Northeast during 2012, “provided a critical alternate supplement to the over-strained natural gas supply system during the polar vortex.” And in the Midwest, “the increased utilization of coal-fired power plants played a similar role providing a necessary substitute for constrained natural gas-fired power plants during the cold snap,” the study found.

But the performance of fossil plants during 2014’s extreme cold conditions was far from perfect.

Fossil-fueled plants had the most failures

According to a North American Electric Reliability Corp. review of vortex conditions in the eastern United States and Texas, while only 3 percent of all forced power outages during the polar vortex were associated with nuclear generation, 26 percent of outages were associated with problems at coal plants, while 55 percent of outages were attributed to disruptions in natural gas supply or generation.

And of the approximately 19,500 megawatts of generation capacity lost during the 2014 cold snap in the Eastern Interconnection and Texas, more than 17,700 MW was due to frozen equipment at power plants, according to NERC. The agency also noted that 700 MW of wind energy in the Texas region experienced low temperature “trips” due to “cold temperatures outside the operating limits of the wind turbines.”

AWEA’s Goggin acknowledged the wind sector faces challenges under extreme cold conditions and that turbines outfitted for cold climates generally stop working at temperatures of minus 30 Fahrenheit, while conventional turbines generally operate into the single negative digits.

But most turbines sending power to the PJM Interconnection, which does not include Texas, during the 2014 polar vortex performed as expected, he said, allowing for an average 3,280 MW of power from wind farms to the grid Jan. 6 and roughly 1,800 MW on Jan. 7, according to the AWEA white paper.

The AWEA paper also stressed other benefits associated with wind power, including its lack of air emissions such as carbon dioxide, its lower marginal costs compared with fossil fuel and nuclear generation, and its ability to send energy to the grid when traditional power plants are unavailable.

“While wind energy output does change with the wind speed, such changes occur far more slowly than the unexpected outages that frequently occur at large conventional power plants,” the paper states. “Moreover, changes in wind energy output are predictable using weather forecasting, while conventional power plant failures are not, making them far more difficult and costly for grid operators to accommodate.”