For millennia, bricks were groundbreaking technology, allowing people to build higher and stronger than before. Now a new startup thinks Bricks will get that title back. But instead of serving as building materials, Electrified Thermal Solutions, which is participating in the TechCrunch Disrupt 2023 Startup Battlefield, hopes they will be the building blocks of new low-carbon industries.
Today, much of heavy industry is dependent on fossil fuels, not only for energy, but also for heat. Obtaining the kind of temperatures needed to make steel, cement or a range of other things is difficult or expensive with current electric heating technology. That has many people looking at hydrogen, which can be burned like fossil fuels without causing any carbon pollution. Unfortunately, developing enough green hydrogen capacity to power heavy industry would also be shockingly expensive.
That’s why startups like ETS are looking at alternatives called thermal batteries. When the sun is shining and the wind is blowing and electricity is cheap, thermal batteries can be charged in the same way as lithium-ion batteries. But when the sun sets or the wind decreases, thermal batteries release that energy as heat instead of electricity.
What happens to that heat is up to the customer. They could use it to generate steam to heat buildings or drive turbines to generate electricity. If a thermal battery can get hot enough, it can be used in steel mills, glass factories, chemical and cement factories, and so on.
ETS’s Joule Hive thermal battery is “98% comparable to stuff you see in the store today,” co-founder and CEO Dan Stack told TechCrunch. The 2% difference from regular refractory bricks comes from semiconductor materials with which the bricks are doped to give them their electrically conductive properties. “We don’t even adjust the recipes a lot to get the properties we need.”
The batteries are heated by running electricity through them — “just like your toaster works, but a lot hotter,” Stack said. The thermal mass of the bricks and the insulated container in which they are stacked allow them to retain their heat for hours or even days. More than 95% of the electricity that went into the bricks can be recovered as heat, he said.
And that heat is hot. A stack of ETS bricks can produce heat of almost 2,000 degrees Celsius (3,632 degrees F), Stack said. “Those are actually flame temperatures. Most industries are used to working with fire, and their flame temperatures approach 2,000 C. So we can do what flames can do, but electrically, and we can do it with a long lifespan. And with a cost-effectiveness that was not even possible before.”
ETS says the cost of its heat is at least three times cheaper than that of hydrogen. Today it is still more expensive than heat from natural gas, but that assumes that natural gas prices will remain low or that there will be no carbon price attached. With a carbon price of $50 per tonne, ETS would be only slightly more expensive than gas.
The company has raised $4.75 million to date, including a $4.5 million seed round led by Clean Energy Ventures that closed in June 2022 and valued the company post-money at $14.5 million.
ETS worked with a brick manufacturer to tailor its recipe to industrial-scale equipment that uses bulk materials. Currently, the company is refining its pilot system, which is about the size of an elevator, Stack said. The next step is something the size of a shipping container, which is currently in the design phase. Once the battery is completed on a commercial scale, ETS will sell heat from the batteries or from the entire system.
It’s all the culmination of about a decade of work that began with Stack’s graduate research at MIT. “We didn’t get here overnight. We started by looking at what is already there,” he said. “But if that’s all you want to do, you’re limited by what’s on the shelf these days. And your electric heaters in particular are the bottleneck. We developed this technology to solve that bottleneck.”