The world is getting hotter, and nowhere more so than in Europe. The continent is warming faster than any other, with countries such as the UK, Switzerland, Norway, and Finland facing significant increases in heat exposure and cooling demand if global warming reaches 2°C above preindustrial levels.
Air conditioning is no longer just a luxury for Europeans; it’s a necessity to protect people from extreme heat. Research estimates that air-conditioning prevented nearly 200,000 premature deaths among people over 65 in 2019 alone.
However, current air-conditioning technology has a significant environmental impact. The electricity they consume already accounts for roughly 3 percent of global greenhouse gas emissions, slightly more than the aviation industry. With new units being installed worldwide every minute, electricity demand for space cooling could more than triple by 2050.
The International Energy Agency (IEA) predicts two-thirds of households could own an AC by 2050. But manufacturers are struggling to find a solution that balances efficiency with environmental sustainability. Conventional ACs still run on a century-old principle: refrigerants cycle between liquid and gas to pull heat out of rooms and dump it outside.
Manufacturers continue to refine the technology, but many of the refrigerants remain problematic. Fluorinated gases, for instance, have a global warming potential thousands of times greater than CO2 if they leak into the atmosphere. The EU has introduced a regulation to phase out these gases gradually, but alternative gases bring their own trade-offs: Propane is highly flammable, while ammonia is toxic.
This impasse has led some scientists and companies back to the drawing board to ask: Instead of searching for a better refrigerant, what if air-conditioning systems didn’t need one at all?
Their answer lies in materials that change temperature when exposed to external forces—a field known as solid-state cooling. This technology could revolutionize how we cool the air around us.
Paul Motzki, professor of smart material systems at Saarland University in Germany, heads an EU-funded scientific consortium focusing on nickel-titanium. When the metal is stretched and released, it snaps back to its original shape, absorbing heat from its surroundings and generating what is known as an elastocaloric cooling effect.
In practice, the technology could be used to cool rooms by 5° to 10°C and do so even more efficiently than conventional AC systems today. The team is currently testing the prototype in the lab, but expects to deploy it in new buildings within the next few years.
If the technology works, it “could lead to disruption, even a paradigm shift, because the technology is so different from established cooling systems,” Motzki says.
The potential impact of solid-state air conditioning on Europe’s energy consumption and greenhouse gas emissions could be significant. As temperatures continue to rise, this new technology may provide a much-needed solution to the continent’s cooling conundrum.
Source: Original article