How Shale Gas Is Helping Renewables

Wind and solar power have an intermittency problem, and natural gas can help solve it. Those two renewable energy sources are on the rise, but as they seek to gain a foothold, suppliers and utilities are scrambling to figure out how to account for the fact that they can only provide electricity when the sun is shining and the wind is blowing. Lacking scalable, cost-effective energy storage, wind and solar have to be relied upon for “peak power” generation, while more traditional fossil fuel and nuclear power plants provide the more consistent “baseload” supplies.

But on those particularly sunny or windy days when renewable power generation ramps up, some of that baseload supply has to be turned off. Conversely, when wind and solar aren’t supplying much, those shuttered baseload plants need to ramp up again. That’s an expensive endeavor, prohibitively so for energy sources like coal or nuclear, both of which require capital investments large enough so as to make that renewables-forced variation financially devastating.

Enter natural gas, which only recently supplanted coal as America’s largest source of electricity generation. Gas-fired plants are cheaper to construct than coal (and much cheaper than nuclear), and are also cheaper to scale up as needed. That makes the economics of turning them off and on according to the whims of weather a lot more viable, and as a result makes them ideal complements to intermittent renewables.

Plenty of these natural gas “peaker” plants are already in use in the United States, but they consume a lot of energy staying in stand-by mode. Now, General Electric says it has a solution to make these peaker plants more efficient by incorporating batteries to make those stand-by operations more efficient. Ars Technica reports:

This week, General Electric (GE) and Southern California Edison (SCE) announced that they had retrofitted a natural gas peaker plant with a 10 MW, 4.3 MWh battery installation to create the world’s first hybrid electric gas turbine. […]

“The energy storage capacity of the battery has been specifically designed to provide enough time coverage to allow the gas turbine to start and reach its designated power output,” GE writes. This eliminates the need to burn fuel while the gas turbine is kept spinning in standby mode.

This is an important step for natural gas power generation, but it’s even more critical for renewables. Wind and solar continue to improve efficiencies while bringing costs down, and it’s now no longer inconceivable that they might operate without government subsidies. Still, their intermittent nature places a hard limit on how far they’ll be able to penetrate power markets. Renewables need natural gas, and as it so happens, the U.S. is flush with that particularly energy source at the moment (thanks to fracking).

Shale gas is already responsible for bringing U.S. emissions down 3 percent last year, and it’s going to be a necessary condition for wind and solar’s future growth. It’s past time for this hydrocarbon to get the green credit it deserves.