Radical change in the Spanish grid: Renewable energy generation profile and electric energy excess

Abstract

The National Integrated Energy and Climate Plan 2021–2030 presented by Spain expected to increase the installed power of renewable energy in 62GW by 2030. However, the electricity operator system (Red Eléctrica Española (REE)) foresees a different scenario, in which the new approved power generation plants (non-synchronous generation i.e.: wind and photovoltaic), for the peninsular system, will reach 84 GW. Moreover, the total power of the request forms, which have license to access the grid, rise up to 143GW. This scenario leads to a new era of power generation in which the generation patterns differ from the current ones diverting the consumption profiles or making imperative new ways of energy storage to be able to reach the expected Renewable Energy share or prevent massive curtailments. The analysis presented in this work is based on the modelling and simulation of the wind and solar energy generation for several scenarios. The results of this analysis show a lack of energy balance (an excess of energy between 92 and 168 TWh with overgeneration during more than 3500 h after balancing mechanisms) due to the non-integrated technologies and due to the (over expected) future installed power derived from REE reports. In addition, the energy available for charging will be higher than the hypothetical discharge to the grid. This allows low charge–discharge efficiencies. Two energy storage technologies: thermal storage for thermal plants retrofitting and reversible hydrogen systems are proposed for analysis. These novel energy balancing technologies are economically modelled and assessed for this specific energy scenario and present moderate paybacks. Even with a high investment in storage facilities, and taking into account the exported energy, the in-excess energy will be very high. This will lead to massive curtailments of renewables (between 35% and 40%) or to a paradigm shift on the energy consumption behaviours.