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Great River Energy’s Battery Is More Publicity Stunt Than Source of Power

Last month, Great River Energy (GRE), the umbrella organization for many of Minnesota’s rural electric cooperatives, announced that they would be shutting down the Coal Creek power plant located in North Dakota decades before the end of of the facility’s useful lifetime. The company has said it will be replacing the electricity generated from the plant with a mix of subsidized wind, buying electricity from other companies when the wind isn’t blowing, and a battery to store electricity generated from wind and solar for use at a later date.

The move received uncritical praise from the media and renewable groups, but a closer look at the proposed battery system shows this aspect of their plan is more of a publicity stunt than source of power.

Batteries Aren’t A Magic Bullet

Confronted with the reality that wind turbines in Minnesota only generated electricity 33 percent of the time, on average, and solar panels only produced 18.2 percent of their potential output in 2018, renewable advocates have insisted that battery storage would be the magical cure that ails the inconsistency of wind and solar.

But, as our friends at the Clear Energy Alliance show in this video, the idea that we can rely on renewables and batteries is pure imagination.

GRE’s Battery

While batteries, in general, will not be able to provide the power needed to keep our society moving full steam ahead, we must look at GRE’s battery, specifically, to see what impact it will have on Minnesota’s electric grid.

According to GRE’s website, the project would be:

“A 1 megawatt, grid connected storage system capable of delivering its rated power continuously for 150 hours. Far longer than the four-hour usage period available from utility-scale lithium-ion batteries today. The battery is expected to be complete by the end of 2023.”

Most people simply don’t understand what any of this language means. In order to figure out what this battery will mean for Minnesota’s electric grid, we’ll take a step back to review the basics of what a megawatt (MW), and a megawatt hour (MWh), are.

When discussing batteries, the MW measurement tells you how much electricity that battery can deliver at one time. A MWh is a volumetric measurement of electricity, telling you how much electricity the battery can store. In this way, a MW is like the speedometer in a car, telling you how much power is being used at one time, and the MWh sign is like the odometer, telling you how many MWh you’ve used. In this case, however, the MWh sign tells you how much power the battery can store.

This analogy isn’t perfect, but it can help us figure out how meaningful the battery GRE plans to install will be within the context of the company’s electricity generation portfolio.

Power Output

To understand the impact this battery will have on GRE’s system, we must compare it to the power plant it is replacing.

The Coal Creek power plant, which will be retired in 2022 unless another company purchases it, has an operating capacity of 1,147 MW, according to an analysis by S&P Global. This means it can supply up to 1,147 MW per hour if it ran at 100 percent of its capacity.

Coal plant’s never operate at their full capacity, however. Instead, Coal Creek ran at a 90.9 percent capacity factor, meaning it produced an average of 1,042 MW per hour during each of the 8,760 hours in 2018.

GRE’s battery, in contrast, would provide 1 MW of power per hour, for up to 150 hours. This means that the battery would be able to provide just 0.096 percent of the electricity generated by Coal Creek, on an hourly basis.

Clearly, the electricity output of GRE’s battery isn’t any where near enough to provide for the energy needs of its customers should we have another situation like the polar vortex of 2019, when it was too cold for wind turbines to operate.

If we round Coal Creek’s output down to 1,000 MW per hour, and think about the plant’s output in terms of a 2,000 calorie per day diet, replacing Coal Creek with this battery is the equivalent of substituting a full-day’s worth of meals for two calories.

Duration

The comparison above may not be completely fair considering GRE was touting the length of the battery’s storage, and not its power output. The company stated:

“Commercially viable long-duration storage could increase reliability by ensuring that the power generated by renewable energy is available at all hours to serve our membership,” said Jon Brekke, vice president and chief power supply officer at Great River Energy. “Such storage could be particularly important during extreme weather conditions that last several days. Long-duration storage also provides an excellent hedge against volatile energy prices.”

However, considering the fact that GRE’s battery could only fill 0.096 percent of the output of Coal Creek,’s output, it is impossible to see how the long duration of the battery could be of much use when the battery is simply incapable of delivering a meaningful amount of power onto the grid, regardless of how long the battery can supply that small amount of power to the electric system.

What Does it Cost?

GRE stated that “commercially viable long-duration storage could increase reliability,” but what exactly does “commercially viable,” mean? We simply don’t know, because GRE never announced how much this battery system would cost its customers. I sent to Form Energy, the company who would be installing the battery, asking how much the project would cost, but have not received any reply.

Conclusion

When it comes to providing affordable, reliable, energy, wind, solar, and batteries are simply unable to get the job done. Despite the praise that is heaped on companies for their investments in battery storage technology, few media outlets report on the limitations of these projects to power our daily lives. GRE’s battery will only replace 0.096 percent of the power output of the Coal  Creek power plant, which makes the battery more of a publicity stunt than a source of power.

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