The Netherlands is working hard on the energy transition; a long-standing part of this transition is that of sustainable heating and cooling. For CRUX, it is clear that the subsurface makes an indispensable contribution to the design of techniques for sustainable energy needs. CRUX provides high-quality design & advice in the field of generating and storing sustainable Geo-Energy.

Thinking in underground energy processes is not a new field for CRUX, as the expert on the design of ground freezing bodies and with extensive knowledge on geohydrological processes, we are able to advise in all types of sustainable energy issues using the subsurface. By actively sharing this knowledge and participating in new developments in this field in cooperation with Knowledge Institutions within and outside the Netherlands, we ensure that we always work according to the state-of -the-art within this very interesting and increasingly relevant field. In cooperation with our knowledge partners, CRUX organised the Energy Geotechnics Symposium in Delft in 2019 and 2023. In addition, CRUX is the initiator in the Netherlands of an innovative method to extract energy from quay wall structures and has been actively working with our partners to apply this technique in Dutch waters since 2019.

Subsurface thermal energy

CRUX has been active in the world of Thermal Storage Systems since 2018. Through consultancy in soil energy, CRUX makes an important contribution to the energy transition. In soil energy, the available energy or energy storage in the soil is used to heat or cool homes, offices, greenhouses. There are mainly two types of soil energy: closed soil energy systems and open energy systems, both aimed at extracting heat and/or cold from the subsoil.


Advising on the environmental effects arising from the interaction between underground construction activities and existing ATES systems was the immediate reason for including ATES in our range of services. An important precondition of ATES systems is that they must operate with long-term stability to effectively provide heat and cold. In densely built-up urban areas, however, the subsoil for this type of system is becoming increasingly scarce and changes are constantly occurring as a result of large-scale new construction projects. The link between our geotechnical and geohydrological design work and ATES systems is therefore a logical step.


Our extensive knowledge of the subsurface and groundwater flows enables us to use stat-of-the-art design models to perform integral considerations of the mutual influence between ATES wells and the environment. We are able to provide clear insight into the influence of deep pile systems, gel injections and diaphragm walls on the ATES systems, and we can use the hydrochemistry of the groundwater to assess the risk of well blockage and the effect on the lifetime of the well.


We are also certified in accordance with BRL11000 for the design of open and closed ATES systems.





Check out our WKO flyer (in Dutch only)

See also our publication in the Water Special of professional journal 'Civiele Techniek' (No 1 2023, in Dutch only).

Energy sheet pile

Waterways form a large part of our Dutch landscape. For the quay walls along these waterways, sheet pile walls are often the chosen bank protection. Because the water in the waterways is warmer than the outside air and is constantly moving, this is an inexhaustible source of aquathermal heat and cold. By turning sheet pile walls into heat exchangers, these structures can easily be turned into a sustainable source of renewable heat and cold.

Since 2019, CRUX has been working with our partner Gooimeer in the development of this innovative system and has completed several pilots in which the operation and application of this system have been extensively tested. Our knowledge and experience in numerical modelling of the subsurface and water enable us to use this data to create advanced and validated design models for the incorporation of this system into Dutch quay walls. In collaboration with TU Delft, TU Eindhoven and University of Milan, we are also working on implementing this system in other European countries through various large-scale research programmes.

For a detailed description of this innovative system and regular updates on its development and project information, visit the website: www.energie-damwanden.nl.

Energy piles

CRUX Engineering has extensive in-house knowledge of designing with Energy Piles as a heat source. An Energy Pile is an foundation pile into which activation loops are inserted, which are then connected to a heat pump as a thermal source. This is a simple way of extracting heat from the shallow subsoil by using the elements that need to be installed anyway. As almost every building in the Netherlands is founded on piles, the potential of this sustainable heating source is huge. The technology has been used abroad for decades and now occurs sporadically in the Netherlands.


Designing a heat source with Energy Piles requires knowledge of the thermal properties of the subsurface and how this is then converted into usable energy in the built environment via a heat pump. CRUX has this knowledge and actively promotes the development of these types of systems by collaborating with companies and knowledge institutes. By using state-of-the-art design models and design tools developed in-house, we are able to work out an energetic design with energy piles that fits in with the environment and does justice to the technical preconditions for such a system.


With this development, the foundation becomes not only the basis of the structure but also of the sustainable energy supply!

CutterSoilMix Energywall

In cooperation with Bodembouw, CRUX is developing the CSM Energywall. The design of CSM walls has been carried out by CRUX for many years according to the latest guidelines and insights. This extremely environmentally friendly system is now used more and more often. Not only in sandy soil layers, but now successfully in the soft subsoil of Amsterdam, where this construction is simultaneously used as cofferdam wall, basement wall and foundation element. Adding pipes to this versatile in-situ wall adds another function to this technique, that of a heat source. Especially in busy inner-city construction projects where environmental influence, nuisance and limited space in the subsurface are an important component for building projects, this combination of function is an extremely suitable design solution.


In two pilot projects, this system was further developed together with Bodembouw and successfully tested with regard to viability and thermal output. The data obtained from these pilots has been the input for an extensive study of this system and has led to an accurate design model for the design of new projects where this innovative technique offers a solution for the busy inner-city subsoil.