There’s no question that the world is facing an energy crisis. Our growing demand for fossil fuels, coupled with their geographic concentration, is putting more and more pressure on price. There’s also concern over the greenhouse-gas emissions associated with combustion, and their impact on climate change. But we can’t solve our energy shortage simply through more drilling or conservation. We have to fix our problems the good, old-fashioned way: through invention.
Demand for electricity is not constant. It fluctuates dramatically with consumer usage. A lot of the capacity of coal, gas, and nuclear generating plants is essentially dormant, waiting to click in when demand rises. But those peaks cannot always be anticipated, and traditional generating stations need time to respond. Even when they can, the grid itself is at risk of overload.
We’ve heard a lot of talk over the past decade or so about the potential of green energy. Hydro was the original eco-friendly source, harnessing the power of fast-flowing water to run turbines. But you can’t just build a hydro generating station anywhere – you need to have the right topography and the right geology.
Wind and sun, on the other hand, can be found just about everywhere, but the power that’s drawn from them is inconsistent and intermittent. The wind doesn’t always blow hard and the sun doesn’t always shine brightly. In meeting peak demand, then, wind and solar are often not there when you need them.
We have to find a way to store energy when it’s plentiful and use it when we need it most. While many have tried to address the problem, no existing battery technology has proven capable of meeting the performance requirements of the grid: uncommonly high power, long service lifetime, and super low cost.
So that’s what I, and a team of bright young MIT students and post-docs, set out to create.
I took inspiration from the Hall-Héroult cell, which revolutionized the production of aluminum. The cell actually has nothing to do with energy storage or electricity generation. In fact, the Hall-Héroult cell is a giant consumer of electricity. But I thought, “What if this device could be reversed to make a cell that can store and deliver electrical energy?”
With this in mind, my team at MIT created a battery that generates enough heat to maintain the necessary high operating temperature, while accumulating a surplus of energy to provide a useable source of power on demand. This way, the battery stores energy as it’s being generated, but also allows some fraction to be used in real time. From there, it’s just a matter of figuring out how to balance it so that the consumer sees continuous supply.
There’s real economic value in this. We pay a lot to have standby capacity that rarely gets used, and this battery would correct that. Knowing that we could meet peak demands with the energy that’s already stored in the system, we would no longer need to generate – and thus pay for – a huge excess of our daily energy needs.
From the university research stage, we’ve now formed a company, Liquid Metal Battery Corporation, that’s attracting the kind of outside investment needed to move beyond the prototypes towards production.
Although these batteries are huge compared to what powers your flashlight or laptop, they’re silent – no moving parts – and emissions free. You could put them places you’d never dream of building a generator fired by non-renewable energy sources. More importantly, they have what it takes to turn renewable energy sources into base-load grid contributors.
Inventing our way out of this energy shortage requires making better use of coal, nuclear, and hydro, as we have them today, and then enabling the new means – solar and wind – to become participants.
Because of their intermittency, wind and solar power have remained in the wings of energy production. We’re now developing a means of moving them towards center stage.
Donald R. Sadoway is a professor of materials chemistry at the Massachusetts Institute of Technology. In 2012, he was named by Time magazine as one of the 100 Most Influential People in the World.