Project Period

2018 – 2022


The main objective of the CHESTER project is the development of an innovative system that allows for energy storage and dispatchable supply of many different renewables energy sources, by combining the electricity and the heat sector. This is achieved through an innovative power-to-heat-to-power energy storage system, the so called CHEST (Compressed Heat Energy Storage) system, combined with smart district heating, thus leading to a very flexible renewable energy management system, which is able to indirectly store electricity with a very high round trip efficiency, site-independent (unlike pumped hydro), cyclically stable (unlike batteries), able to convert power into heat, able to convert low-temperature heat into power, able to store and deliver independently from each other heat and power.

The CHEST system is based on existing technologies (heat pump, thermal storage, Organic Rankine Cycle), but ground-breaking advancements are necessary to ensure high-efficiency and cost-competitiveness.

A high-temperature heat pump consumes surplus electricity from the grid to transfer heat from a low-temperature heat source to a high-temperature storage (130-180°C). The high-temperature storage, based on the phase change material technology, needs to follow the temperatures of the heat transfer fluids of the heat pump (condenser) and the Organic Rankine Cycle (evaporator), so to lose as little exergy as possible.

When electricity is needed, the high-temperature storage can be discharged, working as heat source for an Organic Rankine Cycle.

Results and perspectives

The potential integration of a CHEST system in existing case studies will be preliminary investigated through simulations and the two promising ones will be selected for more detailed monitoring and further analysis. The results from the simulation will also be used to define the requirements for the system components, which will influence their technical development, carried out within the CHESTER project. A complete 10 kWel laboratory CHEST system will be built and tested in a relevant environment.

Key PlanEnergi activities

PlanEnergi is responsible for the preliminary analysis of the case studies as well as developing simulation models on the integration of the CHEST system in these cases. Based on the simulation results, the requirements for the system components will be defined.

PlanEnergi is also in charge of carrying out the political, economic, technological and legislative analysis of the electricity sector in different European countries, so to identify the specifications and requirements that the CHEST system must comply with.

Another task consists of the development of new business models relevant for the deployment of the CHEST concept, as well as the assessment of the renewable energy integration potential, of the market potential for the CHEST system and of its environmental impact.

You can read more about the CHESTER-project in this press release.


Contact persons at PlanEnergi: Per Alex Sørensen and Federico Bava