Bronze Age firebricks could bring the golden age of cheap energy storage

An ancient method of storing heat might be the solution to modern environmental challenges.

This technique involves “firebricks,” which emerged in the early Bronze Age, around 4000-3000 BCE. Their initial use was in kiln lining, but firebricks have since become essential in furnace construction.

Firebricks could enable cheaper, faster renewable energy adoption, according to new Stanford research.

Researchers predict that firebricks could reduce global reliance on batteries by 14.5%, hydrogen by 31%, and underground heat storage by 27.3% — if the world switches to full renewable energy by 2050.

“The difference between firebrick storage and battery storage is that the firebricks store heat rather than electricity and are one-tenth the cost of batteries,” said Mark Z. Jacobson, the lead study author and a professor of civil and environmental engineering at the Stanford Doerr School of Sustainability and School of Engineering.

“The materials are much simpler too. They are basically just the components of dirt.”

Computer model-based study

Firebricks are ceramic blocks that can withstand intense heat.

According to the researchers, insulated containers packed with heat-absorbing bricks may retain heat generated by solar or wind power, making them a stable energy source for industrial uses.

By circulating air through the brick stacks, the stored heat may be released on demand, allowing cement, steel, glass, and paper manufacturers to continue operations regardless of weather.

This could be beneficial for industries such as cement, glass, iron, and steel production. All of these industries demand extremely high temperatures, often exceeding 1,000 degrees Celsius.

The team calculated that the current reliance on fossil fuels for this heat generation adds up to 17% of global carbon dioxide emissions . However, this ancient technique could help cut emissions.

“By storing energy in the form closest to its end use, you reduce inefficiencies in energy conversion,” said Daniel Sambor, co-author and a postdoctoral scholar in civil and environmental engineering.

For this study, the team evaluated the impact of widespread firebrick use in 149 major carbon-emitting nations transitioning to 100% renewable energy sources such as wind, geothermal, hydropower, and solar.

A computer model was used to compare different renewable energy futures.

The first scenario prioritized firebricks for 90% of industrial heat generation. The second scenario completely disregarded thermal energy storage, instead relying on electric furnaces, heaters, boilers, and heat pumps powered by batteries.

The models showcased that using firebricks for heat storage could slash capital expenditures by $1.27 trillion, and decrease grid demand as well as battery needs across 149 countries.

The technique requires less money

The transition to cleaner energy is vital for human health as well. Previous studies have linked fossil fuel air pollution to millions of premature deaths every year.

“Every bit of combustion fuels we replace with electricity reduces that air pollution,” Jacobson said.

This technique is expected to require less amount of money to transition to clean energy sources. With less money, the technology might be deployed faster than other proposed approaches.

“What excites me is that the impact is very large, whereas a lot of technologies that I’ve looked at, they have marginal impacts. Here I can see a substantial benefit at low cost from multiple angles, from helping to reduce air pollution mortality to making it easier to transition the world to clean renewables,” Jacobson concluded in the press release.

Interestingly, several companies are already commercializing these thermal energy storage systems. If adopted on a large scale, this solution has the potential to help achieve the United Nations climate goal of net zero emissions by 2050.

The findings have been reported in PNAS Nexus.