Life on Earth: Hot Battery Technology

Heavy industries such as steel production require enormous amounts of heat. Thermal batteries powered by renewable energy could store this heat and help decarbonize the industry. (Photo: michael_swan, Flickr, CC BY ND 2.0)

Carbon-intensive industries such as steel and chemical production require a lot of heat to operate, most of which comes from burning fossil fuels. Now engineers are working to turn renewable electricity into heat using something called a thermal battery. Inside Climate News reporter Phil McKenna joins host Aynsley O’Neill to explain how the technology works and plans for commercial scale implementation.

Transcription

DOERING: It’s life on Earth. I’m Jenni Doering.

O’NEILL: And I’m Aynsley O’Neill. Nearly a quarter of U.S. greenhouse gas emissions come from heavy industry, such as steel and chemical plants. These sectors require large amounts of heat to operate, and currently most of this heat comes from burning fossil fuels. To help decarbonize these sectors, engineers are working to turn renewable electricity into heat using something called a thermal battery. The technology is still in development, but to find out how it might work, Inside Climate News reporter Phil McKenna paid a visit to a startup that’s testing its design. He’s here to tell us more. Phil, welcome back to Life on Earth!

MCKENNA: Thank you for having me.

O’NEILL: Phil, walk us through the concept of a thermal battery. What is this technology and what could a thermal battery be used for?

MCKENNA: A thermal battery is something that can just hold heat, a lot of heat, preferably at really high temperatures. Thermal batteries are therefore something that would be extremely helpful in decarbonizing heavy industry. So everything from steel production, cement production, chemical plants, food processing, all these industrial facilities require a huge amount of heat. And right now, that heat comes from burning things, usually natural gas, coal, or other fossil fuels, all to create the heat needed to run industrial processes.

O’NEILL: Phil, we already have, you know, different forms of clean energy, solar, wind. How does a thermal battery fit into the broader clean energy landscape?

MCKENNA: So the key challenge for renewables right now is not better solar or better wind – the price of both of those technologies has really, really dropped. The key challenge now is to find batteries that can store this energy until it is needed, until the sun is not shining or the wind is not blowing. So having a technology like this that can convert electricity into heat at a really high temperature and store that heat until it’s needed can really be a game changer.

O’NEILL: You recently looked at a startup called Electrified Thermal Solutions, which has its own thermal battery project, Joule Hive. What distinguishes their design from other thermal battery concepts?

MCKENNA: Everyone is trying to figure out batteries and energy storage, whether it’s heat or electricity. What really sets this company apart is that they do it with commercially available materials, so they can do it very cheaply and on a large scale. So there are many electric heaters that use wires or exotic materials that allow them to really get hot. But they are often very expensive. There are many heaters that work very well at lower temperatures, like the heaters in a toaster. But if you try to do it at the very high temperatures that the industry needs, it will burn out quickly. That’s why Electrified Thermal Solutions uses fireclay bricks, essentially the bricks found in an industrial fireplace or furnace, a truly common material. They then took the regular bricks we use and slightly modified the recipe so that these bricks, which would not normally conduct electricity, now conduct electricity. They take electricity and convert it into heat, and they emit this heat in the same way that a toaster is an electric heater. It turns a bright, hot red that emits the heat, electricity needed to toast bread. So what they discovered and what sets them apart is materials that are very inexpensive and very durable, can withstand really high temperatures and store them until they’re needed.

O’NEILL: All right, this thermal battery, the Joule Hive, how much heat can it store and for how long? How does this relate to what is needed on an industrial scale?

MCKENNA: So a Joule hive can store electricity at temperatures up to 1,800 degrees Celsius, which is higher than the melting point of steel. It can also store this heat for up to several days, which is much longer than any industrial facility would need.

O’NEILL: So they have this concept and proof of concept. But to what extent will thermal batteries become commercially available? Do you know where this technology is in the process of actually being rolled out around the world?

MCKENNA: So this company is still very much a startup. They don’t have batteries on a commercial scale yet. That said, they recently received two federal grants from the U.S. Department of Energy that are enabling them to scale up their operations and allowing them to do so much faster than would otherwise be possible. The first $5 million grant they received earlier this year allows them to build their first commercial-scale pilot project at a test facility in San Antonio, Texas. The second grant they received in March, up to $35 million in federal funds, allows them to build the first commercial Joule Hive battery or battery pack at a chemical plant in Kentucky. The plant is owned by the Ashland chemical company and is a very large chemical plant, powered solely by steam. They need a lot of high-temperature steam. And now they achieve this by burning natural gas. With this grant, they will be able to convert their natural gas heat generation to electrically powered Joule thermal batteries, essentially replacing the burning of fossil fuels with clean electricity to produce this steam.

O’NEILL: Okay, so this is being implemented in Kentucky. There must already be a utility service provider down there. What was their reaction to this technology?

MCKENNA: I talked to Tennessee Valley officials. This is a local Calvert City business. They were delighted with this technology and this project. For them, they face a huge challenge as many industries seek to decarbonize, looking to electrify, which will put a huge strain on their already stressed power grid. They will need to build more capacity to have enough electricity during periods of peak demand. What they really like about this thermal battery is that Electrified Thermal Solutions can draw electricity during off-peak periods of demand when few people need it, and then charge the batteries so they don’t draw power during peak periods when: when others need it.

O’NEILL: So what impact will these batteries have on the chemical plants where they’re tested? Do you know how much they would actually reduce greenhouse gas emissions?

MCKENNA: In the grant award, the Department of Energy said it would reduce greenhouse gas emissions from the plant’s steam generation by 70%. The bigger picture is that about a quarter of all greenhouse gas emissions in the U.S. come from industrial facilities like this chemical plant, and if the way they produce heat at these plants is replaced by fossil fuels replaced by thermal batteries, it was found that could reduce greenhouse gas emissions from all industries by approximately 50%.

O’NEILL: Phil McKenna is a reporter for our partner Inside Climate News. Phil, thank you so much for spending your time with me today.

MCKENNA: Thank you for having me.

Cufflinks

Inside Climate News | “The race for decarbonization is gaining momentum”

Read about electrified thermal solutions

Environmental Protection Agency | “Sources of greenhouse gas emissions”