TREASURE Publishes Policy Brief on the Regulatory Framework for Pit Thermal Energy Storage
The TREASURE project has published a new policy brief analysing how existing EU legislation influences the deployment of Pit Thermal Energy Storage (PTES) technologies across Europe. The brief was developed within Task 7.3 – Key local and EU-wide regulatory and policy messages and lessons learnt, and provides a structured overview of how regulatory frameworks affect large-scale thermal energy storage solutions.
PTES is a promising technology capable of delivering large-scale, long-duration heat storage for district heating systems. By enabling the seasonal storage of renewable heat and supporting power-to-heat flexibility, PTES can significantly reduce reliance on fossil fuels while improving the integration of renewable energy sources.
The policy brief evaluates several key EU legislative frameworks that shape the context for PTES deployment:
Renewable Energy Directive (RED III), which sets binding targets for renewable heating and cooling and defines how renewable heat contributions are accounted for.
Energy Efficiency Directive (EED), which requires Member States to conduct heating and cooling planning and promotes efficient district heating systems.
Electricity Market Design (EMD), which governs system flexibility and participation in electricity markets.
REPowerEU, which supports accelerated renewable energy deployment and energy security objectives.
While these frameworks create favourable conditions for renewable heating and system flexibility, the brief identifies an important challenge: large-scale thermal energy storage technologies such as PTES are not explicitly recognised in several regulatory frameworks. As a result, their contribution to system flexibility, renewable integration, and peak demand reduction may not be fully reflected in market mechanisms or policy planning.
The policy brief also outlines the potential impacts of PTES deployment across the energy system. District heating operators could benefit from improved integration of renewable and waste heat sources and reduced system-level heat generation costs. Municipalities may use PTES as a strategic tool for local decarbonisation strategies, while electricity system operators could benefit from reduced peak electricity demand and improved grid flexibility.
For investors and utilities, greater regulatory clarity would support financing decisions and reduce risks associated with large upfront infrastructure investments. At the same time, end consumers could benefit from more stable heat prices and reduced exposure to fossil fuel price volatility.
By analysing the current regulatory landscape, the TREASURE policy brief aims to support policymakers, energy planners, and market actors in understanding the role that PTES can play in Europe’s decarbonised heating systems.