Impact of special regime generation management on electricity prices: the Portuguese case

Abstract

Purpose The ex-post literature, which evaluates the real impact of renewable generation, is scarce. Most studies are simulations and therefore are not based on real data. This study aims to further this goal using a unique database of the Portuguese spot market, where there are powerful incentives for renewable electricity. Design/methodology/approach This paper analyses ex-post the impact of energy produced in special regime on the wholesale hourly spot market prices of Portuguese electricity during the period 2009–2016. This paper uses standard, two stage least squares and generalized method of moments multivariate regressions and other energy econometrics techniques. Findings It is found that special regime generation has a negative impact on the wholesale price. This impact is higher than that found in other markets. This paper also concludes that using special regime generation to supply the future growth of demand will decrease wholesale electricity spot prices more intensively than using other technologies. Originality/value This paper uses a unique database based on ex-post for the Portuguese spot market. The Portuguese case is particularly interesting, not only because of its strong incentives policy on renewable energy but also because its spot market is interconnected with the Spanish market. This paper contributes to the debate about the sustainability of current renewable electricity support schemes. The decreasing trend in electricity prices, with the introduction of new renewable capacity, can be incompatible with the required payments for non-renewable producers. This paper also shows that even if the price reduction on spot markets is transferred to final consumers, given that it is relatively small (8% spot price which represents 45% of the final price), compared with the cost of incentives (35% of the final price), consumers probably will not be able to support a new investment pipeline with a similar framework.