No idea. Nitinol heat engines are available in toy-size.[1] There used to be interest in shape-memory alloys as robot actuators, but they're slow and need too much power. It takes too much heat to generate mechanical motion.

Does that mean it has high heat pumping capability, since refrigeration is the inverse of a heat engine? I don't know.

[1] https://www.imagesco.com/articles/nitinol/09.html

> Tony Ennis, Exergyn’s chairman, reckons this method of cooling is not only more environmentally friendly than an HFC set-up, but will also be less expensive to buy and 30-40% cheaper to run.

Not absolutely clear, but the cheaper running cost implies it uses less electricity than existing options.