All markets for wind turbines require an estimate of how much wind energy is available at potential development sites. Correct estimation of the energy available in the wind can make or break the economics of wind farm development. Wind maps developed in the late '70s and early '80s provided reasonable estimates of areas in which good wind resources could be found. But new tools and new data available from satellites and new sensing devices now allow researchers to create even more accurate and detailed wind maps of the world.