Effect of the intermittency of non-conventional renewable energy sources on the volatility of the Colombian spot price

Abstract

This paper explores one of the side effects and challenges that integrating non-conventional renewable energy sources poses to the Colombian electricity market, the spot price volatility which is directly related to financial risk. We propose a vector error correction model that allows an integrated and dynamic modelling of the offer-side of the spot market by considering bid prices, available energy, renewable energy production and the spot price. To validate the model, we performed statistical tests on the residuals of the model and back-testing. The results show that given a one standard deviation shock in renewable energy production from non-conventional sources, the spot price volatility increases from 12.7 % to 14.5 % in a 365-day horizon, which represents a relative increase of 14.2 %. Also, when evaluating different renewable energy integration scenarios and the official system expansion, we see that assuming 100 % fulfilment of the non-conventional sources integration plan, the volatility goes up to 31.2 % vs. 12.3 %. It is also worth noting that if the plan is fulfilled up to 25 % there is no significant increase in spot price volatility, which can be justified by the simultaneous expansion of conventional sources that compensate for the effects of non-conventional renewable sources.