A model to explain and predict market-driven investment in renewable energy capital is proposed. The model is suitable for application to the biomass, wind, solar and ocean-derived energy industries. It basically assumes that, given a set of prices and a specific technology, the marginal efficiency of capital invested in these industries only depends on the productivity of the project's site and on its energy transport distance. As suggested by traditional investment theory, the model supposes that only those projects offering marginal efficiencies of capital above the current available rate of interest would be implemented, thus demarcating a region in the productivity-energy transport distance space where all the economically viable projects should lie. By relating this region to the geographic space available for development, total potential investment can be deduced. By using cash flows defined in variable energy transport distance and mean wind speed, a case study for the Chilean wind energy industry is presented. The use of the model to analyse the effect of alternative support schemes for wind energy in Chile is briefly demonstrated. It is concluded that for increasing the area economically available for the development of new wind farms, a research and development support scheme aimed at reducing investment cost of wind turbines by 25% is equivalent to a 20% price subsidy on energy. (C) 2007 Elsevier Ltd. All rights reserved.