Recently, there's been a lot of talk about energy storage being a "holy grail" for solving the problems of deeper renewables saturation in the U.S. power grid. It seems inevitable that someone will officially launch "Holy Grail Storage, Inc.," the term keeps getting thrown about so much.
I'm a big fan of energy storage innovation, and I do believe it's an important solution with big market potential.
But it's time to start pushing back on the rhetoric (from both proponents and, importantly, opponents of renewables) that often slips toward implying that energy storage is the only solution that matters for balancing the grid and renewables. That without such breakthrough innovations, renewables are inherently limited in the near term. Such rhetoric has gone way too far. It's an overstated vision being pushed right now for a variety of self-serving reasons (by utilities, innovators and investors, and then dutifully parroted by various journalists). [Editor's note: We banned the use of the term "holy grail" in energy storage articles at GTM several years ago.]
While it's true that cost-effective power storage is going to be a big boon when it does come to market, we simply do not need such innovations to achieve much more renewables penetration than we currently have in the U.S.
The facts are 1) the problem of intermittent renewables is overstated, at least at current generation-mix levels; and 2) there are a wide range of already-available solutions that greatly alleviate this problem anyway, without requiring additional storage innovations.
There are people out there with a motivation to paint renewables as being some kind of wildly variable power generation source that the grid cannot handle. These people would gladly have you believe that storage is a "holy grail," thus implying that we need to wait for it to be widely and cheaply available. And it's true, the sun doesn't always shine and the wind doesn't always blow when you need it. But let's remember that wind and solar (the dreaded "intermittents") together made up less than 5 percent of U.S. power generation as recently as 2013. Outside of a few specific geographies with high solar and/or wind penetration, this simply is not a big problem today. And there's plenty of headroom. An NREL study (note: link opens a big PDF file) calculated that, with better use of existing dispatchable power and storage technologies, the U.S. could go up to 50 percent penetration of wind and solar and keep the grid balanced.
One canard that these "intermittents" critics throw out there is the variability of a single solar or wind power generation facility. But while there's often correlation across generation sites (my roof is likely sunny when my neighbor's is, true), if you coordinate across a wide-enough range of generation facilities this variability smooths out a great deal. Germany has seen this, with an ability to manage a very deep penetration level of renewables already, somehow keeping the lights on in the process. So all these critics are really pointing out is that our grid in the U.S. is horribly balkanized and uncoordinated, on the whole. New storage tech is seen as a way of simply avoiding having to address this deeper problem, but that's not really the best long-term strategy, is it?
An underappreciated mitigating factor is that solar and wind, together, tend to smooth each other out. Wind profiles often show "shoulders" around dawn and dusk.
So the idea that renewables need a "holy grail" technology breakthrough to keep growing much beyond current levels is simply not true. There's lots of room for significant additional generation-mix penetration of solar and wind, for a long time, before any innovations to smooth out their intermittency will truly be necessary in the vast majority of geographies.
Plus, where intermittent renewables do cause problems, we're a long way from efficiently leveraging already-available solutions to alleviate them. Everyone seems to have forgotten that new battery techs are just one solution for addressing temporary imbalances between supply and demand.
First of all, we can simply better manage demand. Solar and wind conditions, while variable, are quite predictable. A truly smart grid can react to these variable conditions by automatically implementing demand response and ancillary services solutions that already exist, triggering them in response to near-term forecasts or just real-time conditions.
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