Is steam power the future?

By Tom Cheesewright 15 Jan 25 Reading time: 2 mins

General Fusion is building a 70% scale nuclear fusion power plant at Culham near Oxford. It’s due to go live in the next couple of years, and when it does, it will demonstrate our species’ incredible mastery of physics. And do you know what we will do with it? We’ll boil water.

It has always been a weird anachronism that each new generation of power plant has used the same method to convert one form of energy to another. From the first steam engines that spun a bronze pot over fire using opposing nozzles, to the most modern nuclear reactors, the way we convert heat to motion, and latterly to electricity, has always remained the same. We boil water. Could you imagine if Iron Man’s Arc Reactor worked like this? Instead of pumping out gigajoules of energy directly, it was bolted up to a steam turbine? Not very science-fiction.

Of course, we can convert heat to electricity more directly. Spacecraft have long used solid state thermoelectric generators (TEGs) that directly translate heat from radioactive isotopes into electrical current. These are compact and much less complex than steam turbines, so there is very little to go wrong. That’s why we can still communicate with the Voyager probe way out in space, long after 1970s’ battery technology would have failed.

The problem is that, while they are robust and compact, TEGs have always been deeply inefficient. Where a steam turbine generator might reach 40% efficiency, commercially available TEGs might only reach 5%.

“Start-up Mater-AI has created an AI-powered research platform designed specifically to look for new materials that can improve the efficiency of TEGs”

That can change though. The efficiency of a TEG is based on its construction. Varying the materials used, how they are processed and combined, and the mechanical and electrical assembly can all tweak its properties. Significant improvements have been made as our ability to understand materials at the quantum level have increased, with 10% efficiencies or even greater now being seen in the lab.

But we can go further. Start-up Mater-AI has created an AI-powered research platform designed specifically to look for new materials that can improve the efficiency of TEGs. Most devices today rely on some variation of bismuth telluride, first discovered in 1815 and commercialised in the 1950s. But there are likely materials out there with higher potential.

These new materials don’t need to be competitive with a steam turbine to have a huge impact. Imagine hybrid solar panels that convert otherwise wasted heat to electricity. Appliances that recover waste energy. All from a long-lasting, compact component. The possibilities are endless.

And one day, just maybe, we might stop using our most advanced reactors to boil water and spin a turbine.

Tom Cheesewright / Guest writer

Tom Cheesewright is an applied futurist working with governments and global brands to help them to see the future more clearly and respond with innovation. He is the author of two books on foresight and the future, High Frequency Change, and Future-Proof Your Business, and a regular media commentator with thousands of contributions to TV and radio.