Electricity production in highly hydrological-dependent systems is determined by different weather phenomena, which strongly impact spot prices. To account for such stylized facts, we propose a stochastic process with a mean reversion and switching regime component to represent the dynamics of the spot price. The short-term movements are represented by semi-nonparametric (SNP) distributions, in contrast to previous studies that traditionally assume Gaussian processes. We consider the Colombian electricity market as a study case, in which 68% of its electrical generation comes from water resources, and the El Niño phenomenon represents a critical source of risk for maintaining long-term supply, sustainability of investments, and efficiency of prices. We show that under scarcity seasons, the spot price mean, variance, and some superior-order moments of electricity price distribution increase, as does the risk level of the system. In particular, the switching regime model with SNP distributions for the random components outperforms traditional models, leading to accurate estimates and simulations, thus being a helpful tool for resource planning, risk management, and policy-makers for electricity markets with high climatic dependency.
K E Y W O R D Selectricity markets, Gram-Charlier series, risk management, switching regime
| INTRODUCTIONElectricity is involved in most industrial processes and daily human activities worldwide. 1,2 The current commitments that governments, companies, and individuals are making in terms of sustainability are related, to a large extent, to the way primary, renewable, and nonrenewable sources of energy are exploited for conversion or substitution, 3,4 where the implications for going green could imply superior investments. 5 The spot market, forward contract, and futures contract are the most common mechanisms to define the quantities and prices of transactions between sellers and buyers. 6,7 The interplay of these conditions results in a series of prices with certain dynamics different from those of other primary commodities or financial markets. 8,9 According to Benth et al., 10 electricity price exhibit seasonality in several, mean reversion, jumps, and heavy