The best invention since sliced bread? - Rachel Yang
Let’s Begin…
Industrial manufacturers spend a huge amount of energy generating heat to make everyday materials and objects, like cement, steel, and paper. And since most companies use fossil fuels to reach these high temperatures, industrial heat accounts for 20% of our annual global carbon pollution. Thankfully, this is where a century-old technology comes in. Rachel Yang explores how heat batteries work.
Create and share a new lesson based on this one.
Additional Resources for you to Explore
Heat Batteries: A Sustainable Solution for Industrial Heat Storage
As the world transitions to renewable energy sources, one of the biggest challenges remains how to store and use energy efficiently when the wind isn't blowing or the sun isn't shining. Traditional batteries—like lithium-ion—work well for small-scale energy storage but aren't well-suited for high-temperature industrial processes, which require vast amounts of heat. Enter heat batteries, an innovative technology that stores and releases heat efficiently, offering a cost-effective and sustainable alternative to fossil fuels in industrial heating.
How Heat Batteries Work
Heat batteries operate on a simple principle: they store thermal energy in materials such as bricks, rocks, or molten salts and release it as needed. Unlike chemical batteries, which store energy in electrochemical form, heat batteries store energy in the form of high temperatures—sometimes exceeding 1,800°C.
The Science Behind It
Energy Absorption – Heat batteries are composed of materials with high thermal storage capacity. These materials are heated using electricity, often from renewable sources like solar or wind power.
Heat Retention – The system is well-insulated to minimize heat loss, allowing energy to be stored for extended periods. Some designs lose less than 1% of stored heat per day.
Heat Release – When energy is needed, air or other gases pass through the heated materials, absorbing their thermal energy before being directed to industrial processes like steel production, food processing, or chemical manufacturing.
Rondo Energy, a company based in California that has developed a heat battery using stacked bricks threaded with heating elements—much like a giant industrial toaster. Their technology can store and deliver heat for industrial use, eliminating the need for fossil fuels.
Why Heat Batteries?
1. A Low-Cost, High-Efficiency Alternative to Fossil Fuels
Heat batteries are twice as efficient as fossil fuel combustion when it comes to generating industrial heat. Instead of burning natural gas or coal, they store renewable electricity as heat, making them a carbon-free solution. Siemens Gamesa has developed a thermal energy storage system in Hamburg, Germany, using volcanic rock to store excess electricity. This system can hold energy for weeks, addressing intermittency issues with wind and solar power.
2. Decarbonizing Heavy Industry
Many industries—such as cement, steel, and chemical production—require high-temperature heat that has traditionally only been possible with fossil fuels. Heat batteries enable these industries to transition to clean energy sources, significantly reducing carbon emissions. The steel industry, which accounts for nearly 7-9% of global CO₂ emissions, could benefit enormously from heat batteries. In Sweden, Hybrit, a joint venture between SSAB, LKAB, and Vattenfall, is testing ways to integrate heat storage with green hydrogen to replace fossil fuels in steel production.
3. Storing Renewable Energy for Later Use
One of the major drawbacks of solar and wind energy is their variability. Heat batteries act as a buffer, allowing energy to be stored when production is high and used later when needed—whether at night or during low-wind periods. In Denmark, Aalborg CSP has developed a molten salt-based heat battery system that helps district heating networks store and distribute excess energy more efficiently.
Challenges of Scaling Heat Batteries
While the benefits are clear, scaling up heat battery technology faces several hurdles. Here, we offer some potential solutions as well as examples to overcoming these hurdles.
Challenge #1: High Initial Costs
Building large-scale heat storage facilities requires a significant upfront investment. While they save money in the long run by reducing energy costs, businesses may be reluctant to commit without government incentives or subsidies.
Possible Solution: Policies like tax credits and carbon pricing could accelerate adoption. The European Union’s Green Industrial Plan already includes incentives for heat storage solutions, setting an example for other governments.
Challenge #2: Integration with Existing Industrial Systems
Many factories are built around fossil fuel-based infrastructure, making it difficult to retrofit them for heat batteries.
Possible Solution: Some companies, like Rondo Energy, are designing modular heat battery systems that can be installed without requiring major changes to existing production lines.
Challenge #3.Public and Private Investment Needed
Unlike lithium-ion batteries, heat batteries are less well-known, leading to fewer investment opportunities. Without financial backing, large-scale production remains a challenge.
Possible Solution: Increased public awareness, government funding, and private sector investment can help heat batteries become mainstream. In the U.S., organizations like ARPA-E (Advanced Research Projects Agency-Energy) is funding research into high-efficiency heat storage.
The Future of Heat Batteries
Heat batteries have the potential to revolutionize industrial heating and energy storage, reducing carbon emissions, lowering energy costs, and increasing grid stability. Countries and companies that invest in this technology today will be better positioned for a clean energy future. From Denmark’s district heating projects to Sweden’s fossil-free steel initiatives and California’s cutting-edge heat battery systems, pioneers across the world are proving that industrial heat can be clean, efficient, and renewable. The key now is to scale up these innovations and make them accessible to industries worldwide. The question isn't whether heat batteries will play a role in the energy transition—it’s how quickly we can invest, innovate, and implement them at scale.
As the world transitions to renewable energy sources, one of the biggest challenges remains how to store and use energy efficiently when the wind isn't blowing or the sun isn't shining. Traditional batteries—like lithium-ion—work well for small-scale energy storage but aren't well-suited for high-temperature industrial processes, which require vast amounts of heat. Enter heat batteries, an innovative technology that stores and releases heat efficiently, offering a cost-effective and sustainable alternative to fossil fuels in industrial heating.
How Heat Batteries Work
Heat batteries operate on a simple principle: they store thermal energy in materials such as bricks, rocks, or molten salts and release it as needed. Unlike chemical batteries, which store energy in electrochemical form, heat batteries store energy in the form of high temperatures—sometimes exceeding 1,800°C.
The Science Behind It
Energy Absorption – Heat batteries are composed of materials with high thermal storage capacity. These materials are heated using electricity, often from renewable sources like solar or wind power.
Heat Retention – The system is well-insulated to minimize heat loss, allowing energy to be stored for extended periods. Some designs lose less than 1% of stored heat per day.
Heat Release – When energy is needed, air or other gases pass through the heated materials, absorbing their thermal energy before being directed to industrial processes like steel production, food processing, or chemical manufacturing.
Rondo Energy, a company based in California that has developed a heat battery using stacked bricks threaded with heating elements—much like a giant industrial toaster. Their technology can store and deliver heat for industrial use, eliminating the need for fossil fuels.
Why Heat Batteries?
1. A Low-Cost, High-Efficiency Alternative to Fossil Fuels
Heat batteries are twice as efficient as fossil fuel combustion when it comes to generating industrial heat. Instead of burning natural gas or coal, they store renewable electricity as heat, making them a carbon-free solution. Siemens Gamesa has developed a thermal energy storage system in Hamburg, Germany, using volcanic rock to store excess electricity. This system can hold energy for weeks, addressing intermittency issues with wind and solar power.
2. Decarbonizing Heavy Industry
Many industries—such as cement, steel, and chemical production—require high-temperature heat that has traditionally only been possible with fossil fuels. Heat batteries enable these industries to transition to clean energy sources, significantly reducing carbon emissions. The steel industry, which accounts for nearly 7-9% of global CO₂ emissions, could benefit enormously from heat batteries. In Sweden, Hybrit, a joint venture between SSAB, LKAB, and Vattenfall, is testing ways to integrate heat storage with green hydrogen to replace fossil fuels in steel production.
3. Storing Renewable Energy for Later Use
One of the major drawbacks of solar and wind energy is their variability. Heat batteries act as a buffer, allowing energy to be stored when production is high and used later when needed—whether at night or during low-wind periods. In Denmark, Aalborg CSP has developed a molten salt-based heat battery system that helps district heating networks store and distribute excess energy more efficiently.
Challenges of Scaling Heat Batteries
While the benefits are clear, scaling up heat battery technology faces several hurdles. Here, we offer some potential solutions as well as examples to overcoming these hurdles.
Challenge #1: High Initial Costs
Building large-scale heat storage facilities requires a significant upfront investment. While they save money in the long run by reducing energy costs, businesses may be reluctant to commit without government incentives or subsidies.
Possible Solution: Policies like tax credits and carbon pricing could accelerate adoption. The European Union’s Green Industrial Plan already includes incentives for heat storage solutions, setting an example for other governments.
Challenge #2: Integration with Existing Industrial Systems
Many factories are built around fossil fuel-based infrastructure, making it difficult to retrofit them for heat batteries.
Possible Solution: Some companies, like Rondo Energy, are designing modular heat battery systems that can be installed without requiring major changes to existing production lines.
Challenge #3.Public and Private Investment Needed
Unlike lithium-ion batteries, heat batteries are less well-known, leading to fewer investment opportunities. Without financial backing, large-scale production remains a challenge.
Possible Solution: Increased public awareness, government funding, and private sector investment can help heat batteries become mainstream. In the U.S., organizations like ARPA-E (Advanced Research Projects Agency-Energy) is funding research into high-efficiency heat storage.
The Future of Heat Batteries
Heat batteries have the potential to revolutionize industrial heating and energy storage, reducing carbon emissions, lowering energy costs, and increasing grid stability. Countries and companies that invest in this technology today will be better positioned for a clean energy future. From Denmark’s district heating projects to Sweden’s fossil-free steel initiatives and California’s cutting-edge heat battery systems, pioneers across the world are proving that industrial heat can be clean, efficient, and renewable. The key now is to scale up these innovations and make them accessible to industries worldwide. The question isn't whether heat batteries will play a role in the energy transition—it’s how quickly we can invest, innovate, and implement them at scale.
Watch the video and finish the Think section to complete the lesson.
About Earth School
We can save the world. Speed and Scale shows us how to unlock a cleaner, healthier and safer future by laying out a roadmap that will get us to net-zero carbon emissions by 2050. How’s it going to work? We need to electrify transportation, decarbonize the grid, fix food, protect nature, clean up industry and remove carbon. To learn how we’re going to do all that - and to learn how you can take action now - explore this page.
Meet The Creators
- Video created by TED-Ed
- Lesson Plan created by Cheney Munson
