Stefan Larsson-Mastonstråle is an expert in renewable-energy hardware, particularly combined solar heat-and-power systems. He founded Maston AB, a Swedish company developing Sunthetics, a solar technology aiming for far higher efficiency than conventional panels via combined heat capture and energy storage, alongside Stirling-engine and gas-turbine designs. He holds multiple granted patents in this space and has academic ties to KTH Royal Institute of Technology.