Project details



Effective integration of seasonal thermal energy storage systems in existing buildings

Start date: 01.01.2012

Duration: 48 months

Coordinator: Dr Patricio Aguirre

Budget: 9 M€


The Einstein project has as a main objective: to develop, to evaluate and to demonstrate that low energy heating systems based on solar thermal energy combined with Seasonal Thermal Energy Storage (STES) concept and coupled with heat pumps are feasible from a technical and economic point of view. For this purpose, two demo STES installations have been designed, built and monitored in Warsaw and Bilbao and at the moment and for at least two more years, both installations will be monitored and regularly checked by the partners responsible for them.

Apart from both demo installations in operation, the Einstein project has provided other outputs:

  • The development, construction, installation and operation of a new heat pump that allows working with higher temperatures than conventional heat pumps, suitable to be integrated with STES systems.
  • The development of a software evaluation tool for the most cost-effective building retrofitting framework definition (public software tool).
  • The development of a Decision Support Tool for selection, preliminary design and evaluation of STES systems in existing buildings (public software tool).
  • Design guidelines of STES systems for future stakeholders/ promotors/users of STES technology (public deliverable). It is a public report in which the key aspects that should be taken into account for a successful design of a STES system are explained
  • Learned lessons document that summarizes the experiences and knowledge acquired by the consortium from both demos for providing support to future new STES installations.
  • Training material in STES technology at three different levels: for educators, technical staff and for decision makers in seven languages of the consortium.
  • An advance over the state of the art regarding STES tanks construction: a report on “Modular construction description systems for STES technologies” has been developed, which is the first available English report that describes the materials, methods and procedures to realize a STES. With this report the building industries receive the ability to understand the construction of seasonal storages (TTES, PTES and BTES) to derive the design of a single STES and to perform the realization and building process of a single STES. Furthermore, the implemented R+D activities have shown that it is possible to build STES systems with lower specific costs than the older pilot plants of similar sizes.
  • Last but not least, business models for ESCO and no ESCO companies (public, customer cooperatives etc) to exploit STES systems

List of achievements

Link to the EINSTEIN project video can be found here.


Contact person: Patricio Aguirre Múgica