Full text of Donald Sadoway Talks on the Missing Link To Renewable Energy at TED
“Donald Sadoway is working on a battery miracle — an inexpensive, incredibly efficient, three-layered battery using “liquid metal.”” – TED.com
Listen to the MP3 Audio: Donald Sadoway_ The missing link to renewable energy
The electricity powering the lights in this theater was generated just moments ago. Because the way things stand today, electricity demand must be in constant balance with electricity supply. If in the time that it took me to walk out here on this stage, some tens of megawatts of wind power stopped pouring into the grid, the difference would have to be made up from other generators immediately.
But coal plants, nuclear plants can’t respond fast enough. A giant battery could. With a giant battery, we’d be able to address the problem of intermittency that prevents wind and solar from contributing to the grid in the same way that coal, gas and nuclear do today.
You see, the battery is the key enabling device here. With it, we could draw electricity from the sun even when the sun doesn’t shine. And that changes everything. Because then renewables such as wind and solar come out from the wings, here to center stage. Today I want to tell you about such a device. It’s called the liquid metal battery. It’s a new form of energy storage that I invented at MIT along with a team of my students and post-docs.
Now the theme of this year’s TED Conference is Full Spectrum. The OED defines spectrum as “The entire range of wavelengths of electromagnetic radiation, from the longest radio waves to the shortest gamma rays of which the range of visible light is only a small part.” So I’m not here today only to tell you how my team at MIT has drawn out of nature a solution to one of the world’s great problems. I want to go full spectrum and tell you how, in the process of developing this new technology, we’ve uncovered some surprising heterodoxies that can serve as lessons for innovation, ideas worth spreading.
And you know, if we’re going to get this country out of its current energy situation, we can’t just conserve our way out; we can’t just drill our way out; we can’t bomb our way out. We’re going to do it the old-fashioned American way, we’re going to invent our way out: working together.
Now let’s get started.
The battery was invented about 200 years ago by a professor, Alessandro Volta, at the University of Padua in Italy. His invention gave birth to a new field of science, electrochemistry, and new technologies such as electroplating. Perhaps overlooked, Volta’s invention of the battery for the first time also demonstrated the utility of a professor. Until Volta, nobody could imagine a professor could be of any use.
Here’s the first battery — a stack of coins, zinc and silver, separated by cardboard soaked in brine. This is the starting point for designing a battery — two electrodes, in this case metals of different composition, and an electrolyte, in this case salt dissolved in water. The science is that simple. Admittedly, I’ve left out a few details.
Now I’ve taught you that battery science is straightforward and the need for grid-level storage is compelling. But the fact is that today there is simply no battery technology capable of meeting the demanding performance requirements of the grid — namely uncommonly high power, long service lifetime and super-low cost. We need to think about the problem differently. We need to think big, we need to think cheap.
So let’s abandon the paradigm of let’s search for the coolest chemistry and then hopefully we’ll chase down the cost curve by just making lots and lots of product. Instead, let’s invent to the price point of the electricity market. So that means that certain parts of the periodic table are axiomatically off-limits. This battery needs to be made out of earth-abundant elements. I say, if you want to make something dirt cheap, make it out of dirt — preferably dirt that’s locally sourced. And we need to be able to build this thing using simple manufacturing techniques and factories that don’t cost us a fortune.
So about six years ago, I started thinking about this problem. And in order to adopt a fresh perspective, I sought inspiration from beyond the field of electricity storage. In fact, I looked to a technology that neither stores nor generates electricity, but instead consumes electricity, huge amounts of it. I’m talking about the production of aluminum. The process was invented in 1886 by a couple of 22-year-olds — Hall in the United States and Heroult in France. In just a few short years following their discovery, aluminum changed from a precious metal costing as much as silver to a common structural material.
You’re looking at the cell house of a modern aluminum smelter. It’s about 50 feet wide and recedes about half a mile — row after row of cells that, inside, resemble Volta’s battery, with three important differences.
Volta’s battery works at room temperature. It’s fitted with solid electrodes and an electrolyte that’s a solution of salt and water. The Hall-Heroult cell operates at high temperature, a temperature high enough that the aluminum metal product is liquid. The electrolyte is not a solution of salt and water, but rather salt that’s melted. It’s this combination of liquid metal, molten salt and high temperature that allows us to send high current through this thing. Today, we can produce virgin metal from ore at a cost of less than $0.50 a pound. That’s the economic miracle of modern electrometallurgy.