Grid-Scale Metal Liquid Batteries Could Revolutionize Renewable Energy Use

Donald Sadoway Liquid Metal BatteryTED/Screen capture

Most Exciting Development I've Seen in Ages!

Almost every week, I see some R&D project or lab prototype that makes me go "ooh, that's interesting!". But it's rather rare that I encounter something that makes me rethink my whole vision of the future! It happened to me when I saw the video below, which is a presentation by a MIT professor on how he designed grid-scale liquid metal batteries. I won't try to describe Professor Sadoway's design in detail because he does it much better than I could in the must-see TED video below, but I want to put this technology into context and talk about why it got me so excited, and how it truly can revolutionize the important energy sector, and thus be very very good for our fragile biosphere.

But the first thing to note is that Professor Sadoway's grid-scale batteries were designed so cleverly! From the ground up, the goal was to make them dirt-cheap (literally!) and very safe and reliable, which is why they can operate comfortably at high temperatures (something that needs to be constantly cooled has more chances of failing if something unexpected happens). He didn't just try to stretch an existing design into something bigger, he created them to be grid-scale from the ground up. It's truly the kind of genius work that should be backed by massive resources, either from venture capitalists or the Department of Energy or whatever. The faster we can bring these to market, the faster we can ramp up intermittent renewable sources of energy way past the point at which they would start to screw up our current grid infrastructure. And we need all the carbon-free energy we can get, especially with China and India rapidly ramping up their coal usage.

Liquid Metal BatteryTED/Screen capture

Problems & Solutions

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.

Solar Thermal Plant Mirrors Photo

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 Pofessor Sadoway 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!


See also: Amory Lovins Wants us to 'Reinvent Fire' with 50-Year Energy Plan

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