Donald Sadoway talks to TED about the missing link to renewable energy
Missing Link to Renewable Energy: With a giant battery, it would 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 energy do today. The key enabling device here is the battery; 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 of the wings, to the center stage.
The Liquid Metal Battery is a device, of energy storage invented at MIT by researchers. The OED is that spectrum of 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. In the process of developing this new technology, there are some surprising heterodoxies that can serve as lessons for innovation, ideas worth spreading. And to get the nations out of this current energy situation, we can’t just conserve our way out, or just bomb our way out but we have to do it the old-fashioned way.
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. 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 (salt dissolved in water).
The battery science is straightforward and the need for grid-level storage is compelling. But the fact is that the today there is simply no battery technology capable of meeting the demanding performance requirements of the grid, namely on high power, long service lifetime and super-low cost. This battery needs to be made out of earth abandoned elements, something dirt cheap. And it should neither store nor generates electricity but instead consumes electricity; the production of Aluminium, the process was invented in 1886.
Just a few years after the discovery Aluminium changed from a precious metal costing as much as silver to a common structured material, row after row of cells inside resembles Volta’s battery. 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, that the aluminium metal product is liquid.
The electrolyte is not a solution of salt and water but rather salt that is melted. It’s this combination of liquid metal; molten salt and high temperature allow sending high current through. Today, we can produce virgin metal from ore at a cost of fewer than 50 cents a pound and that is the economic miracle of modern metallurgy. It is this that caught the attention of inventing a battery that is all liquid and could capture this gigantic economy of scale.
This has a nameplate capacity of two-megawatt-hours, enough energy to meet the daily electrical needs of approximately 200 American households. So here you have grid-level storage; silent, emission-free, no moving parts, remotely controlled designed to the market price point without subsidy.