How do solar photovoltaic feed-in tariffs interact with solar panel and silicon prices? An empirical study

Preferential feed-in tariffs (FITs) for solar generated electricity increases the demand for solar photovoltaic systems. They can thus induce price to increase, creating the potential for PV systems producers to collect rents. This paper analyses the interactions between feed-in tariffs, silicon prices and module prices, using weekly price data and FIT values in Germany, Italy, Spain, and France from January 2005 to May 2012. Relying methodologically on the Granger causality tests applied to vector autoregressive models, we show that since the end of the period of silicon shortage in 2009, module price variations cause changes in FITs, and not the reverse. This is good news as it suggests that the regulators have been able to prevent FITs to inflate module prices.