The FlexVal report presents a comprehensive analysis of flexibility in district heating (DH) systems, covering technical, economic, and policy dimensions. It examines low‑temperature operation, identifies causes of high return temperatures, and evaluates innovative domestic hot‑water (DHW) substation concepts, including after‑cooling and booster heat‑pump designs. The economic impact of these technologies is assessed under multiple business‑model scenarios (user‑owned vs. company‑owned) and with motivation tariffs that reward lower return temperatures. Network‑level flexibility is explored through the STORM district‑energy controller, which enables demand‑side management, and the PathOpt tool, which optimises DH network topology using non‑linear physics‑based models. A case study in Menen, Belgium demonstrates how incorporating peak‑shaving strategies into network design reduces pipe sizing and total cost of ownership, though it may raise unit energy costs. The report synthesises findings from long‑term system modelling, operational flexibility in Nordic DH, building‑level measures, and network design, concluding that flexibility is a systemic, context‑specific feature that requires coordinated building‑level actions, appropriate business models, and early integration of operational considerations into design and policy.
Topics
Kuopio Heat-Demand Reconstruction via Weather-Degree-Hour Method
A methodology that scales Helsinki heat production data to Kuopio and separates weather‑dependent and independent components using heating‑degree‑hours (HDh). The approach yields an hourly district‑heating demand series for 2022‑2024, enabling accurate long‑term demand reconstruction for the Kuopio network.
Flexibility Scenario Performance and Economic Impact
Comparative analysis of four operational scenarios—no thermal‑energy storage (noTES), TES, demand response (DR), and DR & TES—across three climate years (2022‑2024). The study quantifies impacts on CHP output, electric boilers, biogas ICE units, discarded heat, storage cycling, ramp rates, and total operation costs, highlighting strong sensitivity to electricity‑price volatility and weather variability.
Network Design Flexibility: Demand‑Side Control and Topology Optimisation
Description of the STORM district‑energy controller for real‑time demand‑side management and peak‑shaving, combined with the PathOpt toolbox for non‑linear, physics‑based network topology optimisation (pipe sizing, pressure drops, cost trade‑offs). A fictitious Menen, Belgium case study demonstrates how 20‑30 % peak‑demand reductions lower pipe diameters and total cost of ownership, albeit with a modest rise in unit energy cost.
Network‑Level Flexibility Tools and Menen Case Study
Presentation of the STORM district‑energy controller (forecasting, day‑ahead scheduling, real‑time optimisation) and the PathOpt physics‑based topology optimisation toolbox. The Menen, Belgium case study demonstrates how integrating demand‑side management and operational flexibility reduces pipe sizing, total cost of ownership, while influencing unit energy costs.
Integrated Flexibility Framework and Policy Recommendations
Cross‑chapter synthesis linking long‑term storage, pricing mechanisms, demand response, building‑level measures, and network design into a systemic flexibility framework. Highlights four key take‑aways and provides forward‑looking policy recommendations on regulation, tariff design, and early integration of flexibility considerations.