Bronze age technology could aid in achieving net zero emissions by 2050

Technology rooted in the Bronze age may offer a swift and cost-effective solution to help meet the United Nations' climate goal of net zero emissions by 2050, according to new research led by Stanford and published in the journal PNAS Nexus.

This approach involves assembling heat-absorbing bricks in an insulated container to store heat generated by solar or wind power, which can then be used for industrial processes at required temperatures.

These systems, which several companies have recently begun to commercialise for industrial heat storage, utilise bricks made from materials similar to those in ancient kilns and iron-making furnaces.

However, to optimise for heat storage, the materials are combined differently than for insulation.

"The difference between firebrick storage and battery storage is that the fire bricks store heat rather than electricity and are one-tenth the cost of batteries," explained lead study author Mark Z. Jacobson, a professor at the Stanford Doerr School of Sustainability and School of Engineering.

Many industries require high-temperature heat for manufacturing processes, such as 1,300 degrees Celsius (nearly 2,400 degrees Fahrenheit) for cement production and 1,000 C (about 1,800 F) for glass, iron, and steelmaking. Currently, around 17 per cent of global carbon dioxide emissions are from burning fossil fuels for industrial heat.

Generating this heat from renewable sources could significantly reduce these emissions.

Jacobson and co-author Daniel Sambor used computer models to compare scenarios for a future where 149 countries use renewable energy for all purposes.

In one scenario, firebricks provide 90 cent of industrial process heat; in another, they are not used at all. The firebrick scenario showed a reduction in capital costs by $1.27 trillion, lowered energy demand from the grid, and decreased reliance on battery storage.

"Every bit of combustion fuels we replace with electricity reduces air pollution," said Jacobson. This technology presents a substantial benefit at low cost, accelerating the transition to clean renewables and improving health by reducing air pollution.