Design of an economically efficient feed-in tariff structure for renewable energy development

Evidence suggests, albeit tentatively, that feed-in tariffs (FITs) are more effective than alternative support schemes in promoting renewable energy technologies (RETs). FITs provide long-term financial stability for investors in RETs, which, at the prevailing market price of electricity, are not currently cost-efficient enough to compete with traditional fossil fuel technologies. On the other hand, if not properly designed, FITs can be economically inefficient, as is widely regarded to have been the case under the Public Utility Regulatory Policies Act of 1978 (PURPA). Under PURPA, too high a guaranteed price led to the creation of so-called "PURPA machines" poorly performing generating units that could survive financially only because of heavy subsidies that came at the expense of retail customers. Similarly, because of their adverse impacts on retail electricity rates, German FITs have been subject to increasing political pressure from utilities and customers. In this paper, we propose an innovative two-part FIT, consisting of both a capacity payment and a market-based energy payment, which can be used to meet the renewables policy goals of regulators. Our two-part tariff design draws on the strengths of traditional FITs, relies on market mechanisms, is easy to implement, and avoids the problems caused by distorting wholesale energy markets through above-market energy payments. The approach is modeled on forward capacity market designs that have been recently implemented by several regional transmission organizations in the USA to address needs for new generating capacity to ensure system reliability. (C) 2007 Elsevier Ltd. All rights reserved.