Solar feed-in tariffs in a post-grid parity world: The role of risk, investor diversity and business models

Over the past decade, feed-in tariffs have spurred significant deployment of solar photovoltaics in Germany and other countries. With recent cost trends, several countries are approaching retail grid parity. Some policymakers conclude that now is the time to remove feed-in tariffs, as grid parity creates a self-sustaining market, where economically rational investors will invest even in the absence of government incentives. Recent experience in key European solar markets, however, shows that with the advent of grid parity and the reduction of feed-in tariffs, investment in new solar capacity has decreased rather than increased, making it questionable whether low-carbon energy policy targets will be reached. We conduct a cross-case study analysis of three PV markets - Germany, Italy and Switzerland - to investigate the role of feed-in tariffs for the near- and post-grid parity stages of diffusion, accounting for investor diversity and distinguishing between implications for revenue-based and savings-based business models. We find that recent market trends are strongly driven by increased levels of risk, especially policy risk and exposure to revenue risk. We therefore suggest that relatively frugal but stable policy environments may be conducive to further growth of investment in photovoltaics and minimize cost to society.