Quality assurance for borehole heat exchangers

Part of Today in the Lab – Tomorrow in Energy?

Today in the Lab – Tomorrow in Energy? shines a spotlight on research projects under development in the Technology Collaboration Programmes (TCPs). Learn more about the initiative, read the launch commentary, or explore the TCPs.

Quality assurance throughout design, construction and operation

What is the aim of this project?

Borehole heat exchangers, used in shallow geothermal energy generation, interact with the ground in highly complex ways. Ensuring the consistency of such installations requires steady quality assurance throughout design, construction and operation. This project aimed to examine failures of such geothermal plants from technical, economic and ecological viewpoints. Subsequently, the project developed solutions to improve the installation and maintenance of borehole heat exchangers.

How could this technology be explained to a high school student?

Borehole heat exchangers interact with geothermal heat in shallow subsoil layers down to about 400 m below the surface of the ground. They consist of a heat exchanger inside a borehole, in which a heat-carrying fluid circulates. They can be used in heating or cooling systems, or for long-term underground heat storage. To ensure economic feasibility and ecological compatibility, such systems need to be properly designed and assessed throughout their life.

What is the value of this project for society?

  • increases options for district heating and cooling and thermal energy storage
  • improves safety standards and guidelines for borehole heat exchangers and geothermal plants
  • potentially creates new jobs and businesses in shallow geothermal energy

At what stage of development is this project?

The project started in October 2016 and ended in March 2020. It was closely related to the Energy Storage TCP Annex 27. The project’s results will be published by the end of 2020 and included in the European standardisation work of CEN TC 451 (working group 2), which is in progress.

What government policies could bring this from the lab to the market?

  • referring to CEN TC 451 once it is published
  • promoting quality assurance measures for building borehole heat exchangers
  • promoting training measures for staff in all related fields
  • promoting further research on the topic

Quality Assurance for Borehole Heat Exchangers. Source: QEWS II project partners

Partners and funders


  • ZAE Bayern – Bavarian Center for Applied Energy Research (Co-ordinator)
  • EIFER – European Institute for Energy Research
  • KIT – Karlsruhe Institute of Technology
  • HBC – Hochschule Biberach
  • Solites – Steinbeis Research Institute for Solar and Sustainable Thermal Energy Systems
  • enOware GmbH
  • Burkhardt GmbH.


  • The German Federal Ministry for Economic Affairs and Energy (represented by the Projektträger Jülich).

Learn more

About the Technology Collaboration Programme on Energy Storage (Energy Storage TCP)

Established in 1978, the Energy Storage TCP facilitates research, development, implementation and integration of energy storage technologies to optimise the energy efficiency of all kinds of energy systems and enable the increasing use of renewable energy. The Energy Storage TCP enables high-level co-ordination in research, development, dissemination and market deployment of energy storage solutions.

Contact: energystoragetcp@gmail.com