A member of staff holds a barocaloric material used by Barocal in their solid state cooling technology, at their headquarters in Cambridge, on May 9, 2025. The soft, waxy «solid refrigerant» being investigated in a UK laboratory may not look very exciting, but its unusual properties promise an air-conditioning revolution that could eliminate the need for greenhouse gases. The substance’s temperature can vary by more than 50 degrees under pressure and solid refrigerants do not leak, unlike gases currently used in appliances. (Photo by HENRY NICHOLLS / AFP)
