The effect of sample size on European Union’s renewable energy investment drivers

Macroeconomic modelling results based on relatively varying sample sizes may lead to incoherent results. Such effects have not been adequately understood in the renewable energy literature regarding the European Union (EU). This study focuses on the comparison of results obtained for renewable energy investment drivers (for solar and wind energy investments) on different samples of EU countries, including all EU-27, former EU-15 and 11 high renewable investment EU countries. The study used a random effect panel data modelling approach over the period 1995–2011 for studying the impact of the levelized cost, regulation perception, carbon emissions and climatic condition on wind and solar investments over the three samples. The results demonstrate the importance of trustable regulation schemes to ensure that regulation will not have a significant negative effect on investment, showing also the need to further extend the model to include support schemes as fundamental drivers for investment.