Optimized operation of distributed energy resources: The opportunities of value stacking for Power-to-Gas aggregated with PV

This analysis investigates the business case of a virtually aggregated unit with PV and Power-to-Gas, outlining the added value of enhanced operation modes for the deepened market integration of distributed energy resources in an aggregated form. Based on empirical generation and market data, the presented analysis outlines the added benefit of the so-called value stacking that considers the exploitation of short-term arbitrage opportunities, the provision of secondary and tertiary frequency reserve, and active imbalance management to balance forecast errors. A multi-stage and multi-period optimization approach is presented to generate an aggregated bidding strategy on multiple energy and ancillary service markets. On a case study basis with hourly resolution, annual energy flows and financial outcomes are derived for the modelled plant. Overall, nine different operating modes with different levels of market integration of the aggregated unit are analysed. While static baseline operation results barely profitable, proper integration into energy markets raises the annual cash flow from operating activities to around 60 keuro per aggregated MW. This six-fold increase is accompanied by a much more price-specific dispatch with the equivalent full-load hours of controllable output effectively dropping to about one-third. Integrating the aggregated unit further into balancing markets and performing active imbalance management leverages the freed-up capacity margin and further increases the operational results up to 150 keuro per MW. The provided empirical insights from the case study are beneficial for both practitioners in the energy sector that want to evaluate the potential value of virtual aggregation with enhanced operation and policymakers that consider further regulatory amendments to open markets and enable further integration of new energy sources.