In Focus: Energy Storage

energydata In Focus: Energy Storage

One of the things I enjoy most about shows like Storage Week, sitting through many dozens of presentations on energy storage, is the breadthof perspective on the subject of clean energy.  We all know thatultimately, storage is 100% required if we are to achieve the high rates of penetration we’d all like to see.  That, of course, is a function of intermittency – dealing with fact that the sun shines only during theday, while the wind blows hardest at night, when the demand is at itslowest.  (70% of the total wind energy in California happens at night.)

But here are a few additional ways of looking at storage.  A greatdeal of attention in managing the electrical grid in any given region is placed on dealing with peak consumption on a daily basis – andespecially with the few hours per year that represent the absolutehighest peaks that occur during the summer’s hottest afternoons.  Butgrid managers’ dealings with load fluctuations and resource availability are not occasional incidents.  In one region of the country, thespreadsheet that lists the purchase of “ancillary services,” those thatare necessary to provide the precisely correct amount of power, has850,000 rows (i.e., purchases) annually. 

Thus, from one important perspective, energy storage solutionscompete against gas-fired peaker plants, those facilities that can beramped up and down very quickly to meet peak demand.  How quickly? There are places in the US where weather conditions change dramaticallyand 900 MW of wind goes to 200 MW in half an hour.  And wind is far more predictable than solar, where a cloud can form and blow over a solarfield in a matter of minutes. 

But another completely different ways of looking at storage isfinding a home for off-peak energy generation.  As we put more wind into our grid mix, we get more off-peak wind – and thus more curtailment –the condition where wind turbines must be turned off because the powerthey produce cannot be accommodated.  Curtailment costs wind developershuge sums of money; last year, it represented 5% of the total installedwind capacity.

Yet another viewpoint is demand response.  Utilities pay theircustomers big bucks (in rate reductions) for the right to cut a certainpercentage of power to those customers under peak load conditions. 

So, storage provides a great number of different but importantbenefits.  Yet at the end of the day, the gating factor for storage isessentially political and economic.  Though there is enormous value tohaving storage on the grid, the question is: Who’s going to pay for it?  In an environment like the one we have in the US, where there aredifferent types of entities that generate, transmit, and distribute thepower – each regulated differently, there is no one single entity thatcan rationally be expected to pay for a solution whose benefits do noaccrue solely to that entity. 

As one of the speakers here just told me when I confessed how hardthe business issues here are so hard for me to grasp, “The politicsbehind all this is byzantine.  It’s not terrible in Texas, but it’s atotal mess in California. Powerful interests have succeeding in pushingthrough legislation from which they derived great benefit, but left thestate with a set of regulations that make no sense whatsoever.  Don’tfeel bad if you’re having trouble understanding this.  It took me yearsto figure it out.” 

OK, I feel a bit better, but it sure is a shame that this can’t be more straightforward.