Renewables.ninja is a web tool developed by Imperial College London and ETH Zurich that shows the estimate amount of energy that could be generated by wind or solar farms at any location. The model has been tested by Iain Staffell who is the Co-developer of renewables.ninja, from the Center for Environmental Policy at Imperial College London, and Stefan Pfenninger from ETH Zurich to estimate the productivity of all wind farms in Europe for the next 20 years. German electrical supplier RWE are using it to test their own models of output.