More Wind Turbines, Not Batteries, Could Be Grid Answer

A new study appears to back up the idea that building more wind power in order to meet peak demand – even if the turbines sometimes produce more energy than the grid needs – could be a better strategy than spending resources on trying to store the energy in batteries.

You might recall that this was the fascinating scenario suggested in a study out of Delaware late last year, which found that at a very high rates of renewables penetration, “over-generation is preferred over more storage because excess generation is more cost-effective.”

Similarly, a new study [PDF] out of Stanford University concludes that “if society aims to increase output of (say) wind energy with the least energetic investment, it is better in many cases to just build another wind turbine, or possibly more transmission lines, than to build a battery to store power that arrives at off-peak times.”

You’ll notice a slight difference with the Stanford study compared to the one out of Delaware – the Stanford researchers weren’t trying to come up with the lowest cost scenario like the Delaware researchers, but were instead aiming to minimize energy expenditure. So what they did was look at the life-cycle energy cost of wind or solar energy (the “energetic cost”), then compared the energetic cost of curtailing excess energy produced versus storing it in batteries.

For wind power, curtailing production – turning off the turbines when the energy wasn’t needed – resulted in a 10 percent reduction in the energy return on investment. But storing the energy in batteries was even more costly, with a 20 percent reduction in return on investment for lithium-ion batteries and 50 percent reduction for lead-acid batteries.

With solar, storage beat out curtailment, for the perverse reason that it takes a lot more energy to build and maintain solar panels than it does wind turbines.

“Both wind turbines and photovoltaics deliver more energy than it takes to build and maintain them,” postdoctoral scholar Michael Dale, a co-author of the study, said in a statement. “However, our calculations showed that the overall energetic cost of wind turbines is much lower than conventional solar panels, which require lots of energy, primarily from fossil fuels, for processing silicon and fabricating other components.”

With this big investment for solar, it makes more sense to pay the high cost of storing the energy produced, rather than simply letting it go to waste through curtailment. Just the opposite of with wind. Or as Dale put it, “You wouldn’t spend $100 on a safe to store a $10 watch,” he said. “Likewise, it’s not sensible to build energetically expensive batteries for an energetically cheap resource like wind, but it does make sense for photovoltaic systems, which require lots of energy to produce.”

Pete Danko is a writer and editor based in Portland, Oregon. His work has appeared in Breaking Energy, National Geographic's Energy Blog, The New York Times, San Francisco Chronicle and elsewhere.

  • BobTheJanitor2

    Storage doesn’t make sense for solar for the simple reason that peak energy demands happen while the solar is producing. Trying to turn solar into a baseload plant would result in the power being withheld when it was most useful, and then sent into the grid when it wasn’t.

    Storage makes sense for the grid as a whole: turning nighttime baseload generation into peaking power is very valuable. But it doesn’t matter if the power came from wind, or nuclear, or coal, that storage has value because of the demand curves not because of the supplies curves.

    • Pete Danko

      Solar PV is generally a more reliable producer than wind during high demand periods, but typically solar production is falling sharply as peak demand is arriving. See:

    • Pete Danko

      Plus: Clouds.

      Which isn’t to say that I’m not a solar fan, but clearly — especially when it comes to local solar — energy storage could be a good thing.

      • BobTheJanitor2

        When it is cloudy AC demand falls. And since AC demand is the biggest factor in peak loads, well, that is okay…

  • Alec Sevins

    Great, let’s ravage even more landscapes (like the photo above) in the blind pursuit of “clean” energy for an overpopulated species.

    I’d like to coin a term, “wind blindness,” for people who claim to be environmentalists but treat the landscape, soundscape and bird & bat casualties as necessary collateral damage for their definition of progress.

    • Patrick

      And we’re waiting on your superior solution…

    • BobTheJanitor2

      The stats on bird death say that more are killed by the power lines going to the wind farm, then by the farm itself. Also, cars kill more, as does window glazing, and house cats, (those things are little monsters,) Yes, some bird deaths do happen at wind farms, but the numbers are pretty small compared to most other causes.

  • We should follow Germany’s lead, and cheaply store excess energy as Hydrogen.