According to the Ernst & Young Renewable Energy Country Attractiveness Index, the five most attractive countries for investment are Spain, USA, Germany, UK and India, in that order.

The index provides an overall score for renewable technologies that are currently entering the market on a large scale, i.e. wind, solar and biomass. Wind, as the most important renewable from a business perspective today, is weighted 85%, solar and biomass respectively 5% and 10%. For each technology, an index is constructed based on a mixture of infrastructure and technology factors: