Written by William F. Pickard   

Dear Dr. Moniz:

I was happily astounded by the report today that you, as Secretary of Energy, would "craft a department-wide plan to encourage energy storage – which is critical to integrating renewables into and improving the reliability of the power grid – and present a timeline for doing so within 30 days".

First, I'm clueless as to what this means. Does it mean that you will produce within thirty days a definite schedule for preparing an energy storage plan? Or does it mean that you will, within thirty days, have a well-formed energy storage plan with a definite schedule for making energy storage happen? The two are quite different. The former kicks the can down the road. The latter might actually lead to a few worthwhile accomplishments, but don't hold your breath.

Second, I also don't know what you meant by "energy storage". Detroit auto makers might interpret this as pushing advanced battery technology to get them out of the electric car morass. Farmers might think of storing energy in cellulosic derivatives like wood alcohol. Smart Grid proponents might think that it means stationary energy storage to support power dispatchability during periods of low renewable generation. Cynics might even think that it means repurposing extant DOE programs to make the President's energy stance look better without running his budget any deeper into the red.

Third, even if you mean "Massive Energy Storage to palliate the Intermittency Challenge and support a Smart Grid that depends heavily upon renewables", you will find that there are at least four contending storage technologies in this technical arena, no one of which is currently funded at a level commensurate with the importance of the energy storage problem. Bearing in mind that the Department of Energy seems dominated by devotees of electrochemical batteries, are you going to: (a) Go with the flow, declare batteries the storage winner, put all your money on them, and pray devoutly that they outgrow what one observer has called their Battery Performance Deficit Disorder? or (b) Split the funds evenly amongst the four, risk starving everyone, and probably accomplish nothing of note? or (c) Heed the conventional wisdom that the Age of Fossil Fuel is scheduled to end around 2070, raise a rumpus for shockingly increased funding of all four contenders, and evangelize tirelessly for Massive Energy Storage and the well being of our descendents?

Openness and Transparency demand that the Public be clearly apprised of your positions on these straightforward technical issues.

Oh, and by the way, I deliberately did not mention my personal choices for the four contending technologies of massive energy storage. That way I gave you a chance to guess at my preferences and come up with your own. For comparison, here are my four. What are yours?

Number One. Use renewable energy to capture atmospheric carbon dioxide and recycle it into wood alcohol or iso-octane, which have high energy density, are easy to store, and could maybe prolong indefinitely the internal combustion engine's dominance in transportation. I know this has an "if pigs had wings" sound to it. But there are sensible technocrats who think it might even work, possibly for as little as €110 per barrel-of-oil-equivalent. Trouble is, it's never been tried on a massive scale. So who can tell? But it sounds like a good candidate for a massively pricey demonstration effort.

Number Two. Store renewably generated electricity in gigantic flow batteries. A flow battery has two tanks of liquid reactants that are pumped through a two-chambered reactor to generate electricity. Or, running backwards when there is a surplus of electricity, the reactor can regenerate used reactants. To enable a bigger output current, the reactor is simply made larger. To increase the stored energy, the storage tanks are simply made bigger. Trouble is that, while these devices may work on a laboratory bench, they have yet to be scaled up power grid levels. For the moment, they are but gleams in their developers' eyes. This is a worthy candidate for vastly increased R&D expenditures.

Number Three. Use renewably generated electricity to compress air, which then is stored in underground caverns. When electricity is needed, the compressed air is fed through a massive turbine that actuates a massive generator. This technology ought to work, but has never been tried in a renewable setting that did not also employ auxiliary combustion of natural gas. The challenges of turbine design and of heat transfer are daunting and remain to be worked through in large scale demonstration projects.

Number Four. When renewably generated electricity is in surplus, pump water uphill to an upper reservoir. When there is a shortage of electricity let the water run downhill to a lower reservoir and spin a turbine. This is a mature technology. It works well and has for generations. Its problem is that good sites for the reservoirs are very hard to come by, possibly impossibly hard on the scale that would be needed to back up America's electricity grid. Naturally, candidate solutions to the siting problem do exist. But they've yet to be given realistic field trials, so nobody knows for sure. Funding demonstration efforts to the tune of twenty billion dollars could dispel a lot of uncertainty.

Take Home Message. Thank you for giving Energy Storage some prime time! Just remember that it needs more than encouraging words. It needs massive funding as well.


Yours truly,
William F. Pickard, Ph.D., P.E.