For over 100 years, Iceland has produced renewable energy from geo-thermal and hydro power to heat its homes and power industry. Iceland harnesses the volcanic hot water under the earth’s crust and the energy from damming its plentiful rivers and waterfalls that run through the island. It produces five times more green energy than its population needs. But decisions Iceland has made in how best to use this surplus energy and the environmental and moral impact on its landscape and population have sparked controversy. There have been protests about the international aluminium companies; heavy users of electricity and the more recent advent of data-processing centres like the bitcoin and crypto-currency companies based there. These companies sell their green credentials to customers while consuming all the country’s excess power. When should Iceland say enough is enough? Presenter: Allan Little Producer: Anna Horsbrugh-Porter Editor: Susan Marling A Just Radio production for BBC World Service (Photo: Allan Little visits a deep drilling project in Iceland. Credit: Anna Horsbrugh-Porter)