Scientists have turned to an intriguing place to source cheaper, more efficient energy - blazing-hot magma kilometres below the ground.
At present New Zealand sources about 13 per cent of its electricity from its geothermal assets, drawing out water pre-heated to temperatures of up to 350C from hot rock deep beneath the Earth.
But Canterbury University volcanologist Dr Ben Kennedy said it was possible much more energy could be found from sourcing even hotter fluids at the margins of magma chambers, where temperatures run from 700C to 1200C.
It would mean drilling several kilometres into the Earth with equipment that could withstand the "acidic and supercritical fluids" that would be produced when magma was struck, he told the Herald.
"This concept has long been laughed at by geologists and engineers as science fiction, or a little crazy, but technology is evolving," he said.