Bronze Age technology can help transition to clean energy

A technology with roots dating back to the Bronze Age could provide a quick and cheap solution to help meet the United Nations’ climate goal of reducing emissions by 2050, according to new research. led by Stanford. PNAS Nexus.

The technology involves collecting heat-absorbing bricks in an insulated container, where they can store the heat generated by solar or wind energy for later use in the heat needed for industrial processes. Heat can then be extracted as needed by passing air through channels in the pile of “firebricks,” thus allowing cement, steel, glass and paper factories to run on renewable energy and air. and the light of the sun is not found.

These systems, which several companies have recently started selling for industrial heat storage, are a form of thermal energy storage. The bricks are made of the same material as the waterproofing bricks that were on ancient furnaces and iron furnaces thousands of years ago. To improve the heat storage instead of the input, the materials are combined in different quantities.

Batteries can store electricity from renewable sources and provide electricity to generate heat when needed. “The difference between firebrick storage and battery storage is that the bricks store heat instead of electricity and are a tenth of the cost of batteries,” said lead study author Mark Z. Jacobson, professor of civil and environmental engineering at the Stanford Doerr School. of Sustainability and School of Engineering. “Materials are much simpler. They’re basically particles of waste.”

To maintain a high temperature

Many industries require high temperatures for production. Temperatures in factories require at least 1,300 degrees Celsius (about 2,400 degrees Fahrenheit) to produce cement, and 1,000 C (about 1,800 F) or hotter for glass, metal and to make iron. Today, about 17% of all carbon dioxide emissions worldwide are caused by burning fossil fuels to generate heat for industrial processes, according to calculations by Jacobson and co-author Daniel Sambor. . Generating industrial heat from renewable sources can offset these emissions.

“By storing energy close to its end use, you reduce the inefficiency of converting energy,” said Sambor, a postdoctoral fellow in civil and environmental engineering. “It is often said in our field that ‘if you want hot showers, keep hot water, and if you want cold drinks, keep ice’; so this lesson can be summed up as ‘if you need heat for industry , save it with firebricks'”.

Great savings

The researchers intend to examine the effect of using fire bricks to store a lot of industrial heat in 149 countries in a hypothetical future where each country has switched to wind, geothermal, hydropower, and solar for all energy projects. 149 countries account for 99.75% of the world’s carbon dioxide emissions from fossil fuels. “Our study is the first to examine large-scale renewable energy conversion with firebricks as part of the solution,” Jacobson said. “We found that firebricks make for a quick and affordable transition to renewables, and it helps everyone in terms of health, climate, jobs and energy security.”

The team used computer models to compare the costs, land requirements, health effects, and emissions involved in two scenarios for a hypothetical future in which 149 countries by 2050 use renewable energy for all energy purposes. power. At one level, fire bricks provide 90% of industrial heat. On the other hand, there are firebricks or other types of thermal energy storage for industrial applications. In the absence of fire bricks, the researchers thought that the heat for industrial processes would come instead of electric furnaces, heaters, boilers and heat pumps, with batteries used to store electricity for of those sciences.

The researchers found the firebricks scenario could reduce financial costs by $1.27 trillion across 149 states compared to a scenario without firebricks, while reducing the demand for grid power. and the need for energy storage from batteries.

Clean energy, clean air

Solutions to accelerate the transition to clean energy are also linked to human health. Previous studies have shown that air pollution caused by the burning of fossil fuels causes millions of deaths every year. “Every fossil fuel we convert into electricity reduces that air pollution,” Jacobson said. “And because there is less money to change at a higher speed, to reduce the cost to the overall system, the faster we can implement it.”

Jacobson has spent his career understanding air pollution and climate issues and developing energy plans for states, countries and cities to address these issues. But his focus on firebricks is relatively new, driven by a desire to find practical solutions that can be adopted quickly.

“Imagine if we propose an expensive and difficult way to switch to renewable energy – we can have very few people. But, if this will save money compared to the previous way , which will be implemented quickly,” he said. “What interests me is that the effect is very large, while most of the technologies that I look at, have small effects. Here I see a great benefit at a low cost from many angles, helping to reduce the death of pollution of air. making it easy to convert the earth to clean renewable resources.”