Why Energy Storage Is the Future of the Grid

Renewable energy makes up a greater part of our power supply than ever before, with rapid deployment of wind, solar, hydro and other sources contributing to greener energy worldwide. But there’s a problem. Renewable sources like solar and wind don’t always produce the?right?amount of power at the?right?time.This week’s podcast guest runs a company that looks to solve that challenge.?Ramya Swaminathan is CEO of Malta Inc,?a spinoff from Alphabet’s moonshot factory, X. Her company ingeniously repurposes old-tech – and uses molten salt –?to convert electricity into heat. That heat can be converted back into electricity to meet demand.?

My conversation with Ramya was brilliant. We discussed why solving the energy storage problem is essential to developing a green grid, how entrepreneurs and policymakers can make that happen, and why the future of energy could arrive sooner than you might think.

You can ???listen to the podcast?or ???read a transcript?here. Members of my Exponential View newsletter receive this brief early on Thursday of every week. Join my community.

The Big Idea

Solar panels can’t generate electricity when the sun isn’t shining; wind turbines can’t produce on a still day. That problem – known as intermittency – stops renewables being reliable.

Too?much?electricity can also be a problem. If renewable energy sources produce an excess of electricity when the grid doesn’t need it, they might face curtailment –?a temporary reduction in output. That’s inefficient, and can (if you’ll pardon the pun) turn off investors who want to be sure their capital is working to maximum available potential.

As the use of renewables increases, policymakers, investors and entrepreneurs are becoming more aware of these dynamics. The need for energy storage – the capacity to squirrel away electricity for later use – is becoming a hot topic.

Malta is one of many companies looking to solve the problem of grid storage:

[I]t's a big table with a lot of seating for a variety of technologies that provide different services, that provide different levels of duration, that serve different scale points in the market.

Source:?Contrarian Ventures

How Malta’s System Works

Malta uses molten salt alongside well-known industrial processes and components to convert electrical energy into heat. When the grid needs a boost, that heat can be converted back into electricity to plug the gap:

Source: Malta Inc.

So far, lithium-ion battery technology has emerged as the frontrunner in the energy-storage scramble. Li-ion batteries are good at storing energy for four to six hours, but that’s not enough. As Ramya says, consumers expect that when they flip a switch, their lights will go on. Since an energy source like solar can produce for about six to eight hours a day, our future grid will need systems that can store energy for longer.

You essentially need to have discharge duration of the remaining call at sixteen to eighteen hours. If you are charging for six hours, you'd need to be able to service the rest of the day.

In theory, it should be relatively easy for Malta to add greater duration – in other words, to store energy for longer – simply by adding more material:

[T]he energy part of the system [...] sits in the form of molten salt and a commodity antifreeze fluid on the cold side. So extending duration from 10 to 20 to 30 hours and beyond. That is really a matter of adding more salt and adding more coolant. And what's more, it's the cheapest part of the system and so on a per kilowatt hour basis, the longer the duration […] your installed cost goes down.

Beyond that, there’s an even greater aim: seasonal storage. Imagine a world in which we can charge our grid during the summer months, and live off that energy through the cold winter without burning fossil fuels. Grid perfection.

Ramya and I also discuss:

• ?? Why progress in grid storage could hit an exponential tipping point [08.10]
• ?? How Malta could convert coal plants and stem job losses [21.10]
• ?? How a decentralised grid will change the energy market [46.40]

Listen to this, too

Back in April 2020?I spoke to Ramez Naam, an investor and technologist, about the race to decarbonise our planet. We discussed the virtuous cycle that drove down the price of renewables, how to overcome the energy storage problem, and why the production of construction materials presents a huge opportunity to make our planet greener. You can?listen to that conversation here.