European Project GEO4CIVHIC - Most Easy, Efficient and Low Cost Geothermal Systems for Retrofitting Civil and Historical Buildings

The building retrofit market today barely reaches 1 % of the actual building stock. In addition, the interventions are of shallow nature in the majority of the buildings. The energy transition initiative of the European Commission is focusing on increasing the retrofitting of the building stock from the current 1 % level to 3 % and to shift the nature of the interventions towards deep retrofits. The GEO4CIVHIC project (https://geo4civhic.eu/) is one further step of many in research and innovation to increase shallow geothermal applications in buildings. The revision and implementation into legislation of the EPBD, the Energy Efficiency Directive and the Renewable Energy Directive by the EC, coupled with financial support mechanisms (e.g. tax reductions for deep retrofits, premiums for renewable energy systems) will contribute as well.

The GEO4CIVHIC activities are organized in three groups named blocks. The first group (technical block) deals with the technical innovations and solutions to be realized and demonstrated starting from the state of art and the specific needs of building retrofits. The high drilling cost needs to be tackled. Drilling with highly efficient but heavy and large drilling machines is difficult and often impossible in the built urban environment. The use of smaller, less powerful machines leads to even higher drilling costs. Hence increasing the thermal efficiency of the Ground Source Heat Exchangers (GSHEs) is another way to reduce the total length (and therefore the costs) of GSHE system to be installed. Innovations are introduced in each component: Drilling Machines and Methodology, GSHE design and materials, compact and hybrid heat pumps (HPs) for high and low temperature terminals. Development of the heat pumps should also contribute to the decrease of the total investment or the increase of the overall efficiency. Heat pumps with good performance at higher temperatures avoid the need to replace all or parts of the heating terminals. A Decision Support System (DSS) will deliver the most suitable technical solution for each facility and a Building Management System (BMS) will allow the use of other renewable energy sources and optimization of the controls.

The second group (economic & market block) addresses the introduction of these technologies to the market. The stakeholders united in the broad consortium, including architects, drilling machine builders, drillers, HP suppliers, engineers and academics specialized in shallow geothermal applications, HVAC systems and HPs will provide their expertise. The stable nature of geothermal as a renewable energy source, the ability of heating/cooling with only one system and the higher residual value of buildings retrofitted with this technology are additional key factors for investors who are focusing on the long-term value of retrofits.

The third group (environmental & standardization block) deals with the legislative, environmental and European standard aspects, dealing with the project innovations for which recommendations and modifications will be developed through experienced consortium partners being members of standards organizations and geothermal associations.

The main goal of the GEO4CIVHIC project will be to tackle all of the above-mentioned areas by developing and demonstrating more easy to install and more efficient GSHEs, using drilling machine innovations tailored for the built and also historical environment and developing or adapting heat pumps and other hybrid solutions for retrofits through a holistic engineering, construction and controls approach.