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 integration of distributed energy resources. Such an aggregated unit can not only leverage the internal benefits of acting as a single unit, for example, by reducing imbalance errors and respective payments but also by offering a larger variety of products and services to the system than each unit could offer individually. Based on empirical generation and market data, the presented analysis outlines the added benefit of the so-called value stacking implementing the balance of forecast errors, the exploitation of short-term arbitrage opportunities, and the provision of secondary and tertiary frequency reserve. A multi-stage and multi-period optimization approach is presented to generate an aggregated bidding strategy on multiple energy and ancillary service markets. On the one hand, the results highlight the value of individual operation modes for the plant and, on the other hand, the aggregated benefit of value stacking with multiple combined operating modes. The provided empirical insights are beneficial for both potential investing parties that want to evaluate the potential value of combined plants and policymakers that consider further regulatory amendments to open markets and enable further integration of new energy sources.
Keywords ancillary services, hydrogen, intermittent renewable energy, power to gas, value stacking, virtual power plant (VPP)