Low-enthalpy geothermal energy: easier installation for buildings and businesses

Low-enthalpy geothermal energy can play an increasingly important role in the decarbonisation of buildings , especially when integrated with heat pumps and high-efficiency plant systems . It is a technology capable of exploiting the relatively stable temperature of the subsoil to contribute to heating , cooling and the production of domestic hot water , reducing the use of fossil fuels .

The new decree from the Ministry of the Environment and Energy Security aims to simplify and speed up the installation of low-enthalpy geothermal systems for buildings and businesses . The goal is to introduce clearer and more uniform rules across the country, providing greater administrative certainty for citizens, operators, designers, and installers.

Free activity and PAS: two procedures based on the size of the implant

The decree introduces two simplified procedures, differentiated based on the size of the system and the depth of the probes. For existing buildings , systems with a thermal power of less than 50 kW and probes installed up to 80 meters deep (vertical probes) or up to 2 meters deep (horizontal probes) may be installed under the Free Activity regime.

In this case, no permits or prior authorizations will be required: it will be sufficient to send a communication to the SUER – Single System for Renewable Energy platform within five days of activation.

For larger systems , the Simplified Authorization Procedure is applicable to systems with thermal power up to 500 kW and probes up to 250 meters deep for vertical installations, or up to 3 meters for horizontal installations. In this case, the applicant must submit the notification using the single PAS form on the SUER platform before starting work.

For the HVAC sector, this distinction is particularly important because it allows for the identification of authorization procedures that are more proportionate to the scale of the intervention, simplifying especially the most common applications in the residential, tertiary, and small business sectors.

Technical requirements and protection of the subsoil

Administrative simplification does not eliminate the need for careful planning. The decree, in fact, provides technical requirements aimed at ensuring safety, protection of the subsoil, and proper integration of the systems into the installation context.

Key aspects include:

• minimum distances from neighbouring lands , to avoid interference of the thermal field with third party areas or properties;
• geological and thermal characterization of the subsoil for plants between 50 and 500 kW;
• possibility of using literature data or stratigraphies available for systems up to 50 kW;
• use of materials compliant with the applicable UNI technical standards;
• use of low environmental impact carrier fluids , with preference for drinking water or equivalent solutions in terms of toxicity and biodegradability;
• corrosion resistance for underground pipes and valves.

These elements confirm that shallow geothermal energy requires multidisciplinary expertise. It's not enough to simply size the heat pump: it's necessary to evaluate the subsoil, probes, thermal field, system distribution, building needs, and operating conditions.

Digital census and new opportunities for the HVAC supply chain

The measure also introduces methods for monitoring and recording installations . Regions and autonomous provinces will be required to establish a digital registry to monitor installations. For plants under the Free Activity Scheme (FAP) regime, essential data will be required, such as location, power, and dates of construction, while for those under the PAS regime, the documentation will be more detailed and must include the geothermal system design and a technical report on the works performed.

This approach can contribute to a more orderly development of the sector, improving awareness of the installed base and the quality of available information. For designers and installers, the register also represents a useful tool for strengthening the traceability of interventions and enhancing the required technical skills.

Simplifying processes can open up new opportunities for the HVAC industry, especially in energy retrofit projects for existing buildings. Geothermal heat pumps , in fact, can offer high performance and greater stability in response to external climate variations, proving particularly attractive when the goal is to reduce consumption, emissions, and dependence on fossil fuels.

The new regulatory framework, if accompanied by qualified planning and accurate information, can therefore foster a greater diffusion of shallow geothermal energy. The challenge will be to transform administrative simplification into well-designed, safe, and truly effective interventions for buildings, businesses, and local communities.