In 2025, Poland curtailed an estimated 1.4 TWh of renewable energy – double the amount from 2024 – while the number of hours with negative electricity prices rose to 315. Experts argue that instead of shutting down wind and solar farms, this surplus power could be absorbed by the district heating sector through Power-to-Heat technologies and thermal storage.
According to a report by the Polish Wind Energy Association, RE-Source Poland Hub and Horizons Power to Heat, the growing frequency of negative prices and non-market redispatching is a symptom of insufficient demand-side flexibility. The report stresses that the key challenge is no longer how many new renewable megawatts can be connected, but how to efficiently use the excess generation locally.
District heating appears as a natural large-scale consumer of this flexibility. In 2024, licensed district heating companies produced 367.1 thousand TJ of heat (around 102 TWh), of which 206.8 thousand TJ (57.4 TWh) reached end customers connected to the network. For comparison, Poland’s total gross electricity generation in 2024 stood at 169.3 TWh.
Power-to-Heat as a system asset
Technologies such as electrode boilers, resistance heaters, large-scale heat pumps and thermal storage allow converting momentary electricity surplus into usable heat. Unlike battery storage, which focuses on short-term arbitrage, thermal storage can act as low-cost, large-scale absorption infrastructure and shift heat usage over time.
– District heating can become a ‘negative power source’ for the national power system: it does not feed electricity back into the grid, but in hours of surplus it increases controllable consumption, turning it into heat and shifting its use in time – the report explains. This function is particularly valuable during high PV generation or strong wind output when electricity demand is low.
For the transmission system operator, Power-to-Heat adds controllable demand that can reduce curtailment and the need for emergency redispatching. For heating plants, it offers access to a heat source whose cost depends on low hourly electricity prices, not on volatile fossil fuel and CO2 prices. For heat consumers, it may slow tariff increases if the tariff system passes on the benefits of cheap energy and storage.
Regulatory hurdles and the real bottleneck
The authors note that the regulatory environment is largely ready: the Energy Efficiency Directive and Renewable Energy Directive create permanent demand for renewable heat, while the ‘green hours’ mechanism and flexible distribution tariffs give tools for demand control during surplus windows. However, the real bottleneck is the structure of distribution costs – including capacity charges and variable/ fixed fees – which neutralise the benefits of cheap surplus energy exactly when the system needs flexible demand the most.
– The bottleneck today is not the law, but the cost structure of distribution – the capacity fee and variable and fixed charges – which neutralises the benefits of cheap surplus energy exactly in the hours when the system most needs flexible demand – the report concludes. The authors recommend treating Power-to-Heat as part of systemic infrastructure, not merely a local heat source, and optimising its operation not for maximum annual running hours but for hours with the highest system value: low or negative prices, high renewable generation and risk of non-market redispatching.
Źródło: WNP.PL, Fot. Shutterstock
