TecKnow of the day
Renewable energy sources like wind and solar have great advantages over other sources; once operating, they don’t produce greenhouse gases or air pollution, they have no fuel costs, and they can more easily be scaled up or down to either take full advantage of a very sunny spot in a desert or very windy site offshore, or fit on a rooftop in a city.But they also have a big disadvantage, which is that we can’t truly control when they produce energy. Once the sun is shinning or wind blowing, we can tweak them to maximize output, and we can forecast wind and sun with pretty good accuracy, but despite all that, it remains that sometimes there’s just no sun or wind.
Workarounds exist, but they come with their own problems. For example, you can have backup power plants that take over when there’s a shortcoming of renewables. Or you can import renewable energy from another region where the wind is blowing and/or sun is shinning, or from a region that isn’t producing electricity from intermittent sources.
The problem is that this only works with relatively small amounts of intermittent renewable sources in the system. If wind power makes up 5% of the total and half of it goes down, that’s only 2.5% of total. You can probably deal with it by ramping up production at other power plants, or firing up backup ‘peaker’ plants, or by importing power from another region.
But if our goal is to make wind and solar much bigger players, we run into big problems. If wind and solar are 75% of total energy production capacity in the system, we can’t expect to have enough backup power plants that sit idle most of the time at the ready to pick up the slack. That would just be too expensive. It’s also not practical to overbuild solar and wind capacity up to a point where any region that gets sun and/or wind has enough overcapacity to always export power to other regions where there is no sun or wind. And with this much wind capacity, we also run into the problem of maybe having strong winds at night when there is very little demand, and then almost no wind during peak time on very hot days when everybody is running their A/C.
That’s what affordable grid-scale storage of the kind PofessorSadoway proposes could help us with. It would not only make our current grid more efficient by allowing us to capture excess power produced off-peak and using it during the time of highest demand, but in the long term, it would allow us to ramp up the use of wind and solar to a point that would be extremely hard to reach without it. So kudos to Donald Sadoway, and I wish him the best of luck developing this potentially world-changing technology!