The power grid has traditionally been operated using large production plants from which the electric power is being dispersed to the end-users. However, the integration of variable renewable energy sources (VRES) is happening at an accelerated rate, largely facilitated by the drop in prices for wind and solar power. Consequently, the power system is shifting from primarily consisting of centralized power plants towards more distributed energy production. At the same time, there are larger power, and energy demands due to the increased electrification, e.g., within the transport sector and industry.
The intermittent nature of production from VRES will often not coincide with the energy demand. Therefore, energy storage solutions such as battery energy storage systems (BESS) and hydrogen energy storage systems (HESS) are expected to be important for integrating large shares of VRES in the power system. However, high investment cost is still one of the main barriers for large scale deployment of BESS. Hydrogen is better suited for long-term energy storage but is considered an inefficient energy carrier due to the large amounts of energy lost during production.
Increasing the deployment of BESS and HESS will, thus, require further development of these technologies to reduce costs and improve efficiency. However, it also requires a better understanding of how they should be operated to maximize their socio-economic benefits. Therefore, the MultiStore project aims to develop operation strategies for these energy storage technologies to further facilitate more VRES in the power grid. These strategies can then be used to get a better understanding of the challenges and the incentives required to deploy and combine different energy storage solutions. The project has been organized into three main work packages (WPs):
WP1 – “Optimal control of ESS for individual actors” aims to develop control strategies that maximizes the profitability for the ESS operators by participating in multiple markets. A novel control algorithm has been developed, which accounts for degradation caused by various factors—such as the depth of discharge (DoD) and the mean state of charge (mSoC). This allows the algorithm to estimate expected degradation losses when the ESS is used for different services. The next step is to further enhance the algorithm by incorporating additional degradation factors and improving its ability to handle uncertainties in market prices, load demand forecasts, and power generation from variable renewable energy sources (VRES).
WP2 – “Operation of ESS in the power system” focuses on how ESS should be operated and placed to maximize the benefits for the power system, e.g. by allowing for better utilizing of VRES. These algorithms also need to account for the stochastic and intermittent nature of the VRES as well as the physical constraints of the power grid. Additionally, both long- and short-term storage needs to be considered by the operation strategy. As part of WP2, the openly available energy system modelling framework EnergyModelsX is being further developed to support the import of power system models. This enhancement will enable simulation and optimization of ESS sizing and operation while accounting for interactions between the electrical grid and other energy carriers, such as hydrogen and thermal energy.
WP3 – “ESS incentives and socio-economic impact assessment” will perform simulations using multi-agent methodology to assess and develop different incentive schemes that combines the interest from the ESS owners (WP1) and grid operators (WP2). As a result, it will be possible to analyse the socio-economic impact of different ESS and how improvements in these technologies will benefit the different actors in the power system. Initial work has demonstrated how an ESS owner's revenue may be affected when required to provide voltage support at the distribution level, in addition to participating in frequency regulation markets.
MultiStore will develop control and operation strategies for battery energy storage systems (BESS) and hydrogen energy storage systems (HESS) with the aim of maximizing their socio-economic benefits to further facilitate more VRES in the power grid. Operation algorithms for both the owners (bottom-up) and the grid operators (top-down) will be developed and used to get a better understanding of the incentives required to deploy and combine different energy storage technologies.
