PersonFounderExecutive
James Macnaghten
James Macnaghten is the co-founder and CEO of Caldera, a Hampshire-based climate-tech company turning cheap renewable electricity into stored industrial heat using blocks of volcanic rock and recycled aluminium. A Cambridge-trained mechanical engineer with 25+ years in business and 20+ patent families to his name, he spent a decade running grid-storage pioneer Isentropic before founding Caldera in 2017. He also owns Scudamore's Punting Co, Cambridge's largest tourist business. In 2025 Caldera closed a Series A backed by Germany's GEA Group and landed its first major order, a 10 MWh storage boiler for an NHS hospital.
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