Geothermal Probes Decree, the new rules

How the rules for small geothermal energy change

(Rinnovabili.it) – The puzzle of simplifications introduced at the beginning of the year with the Energy Decree (DL 1 March 2022, n.17). In the last days of the Draghi government, the Minister for Ecological Transition Roberto Cingolani has in fact signed the awaited Decree geothermal probesprovision dedicated to small geothermal. The DM was created with the aim of establishing the requirements for the installation of geothermal probes intended for the air conditioning of buildings. By identifying the cases in which to apply the simplified authorization procedure (PAS) and those where installation can be considered free building activity.

Decree geothermal probes, when the plants do not need permits

The MiTE Decree on small geothermal energy explains that in order to consider the installation works for free building interventions, the closed-circuit geothermal probes must extend to a depth of no more than 2 meters if horizontal, or 80 meters when vertical. Furthermore, the power of the geothermal plant must not exceed 50kWnor alter the volumes of the buildings or involve interventions on structural parts.

The simplified authorization procedure, on the other hand, is applied to systems with up to 100 kW of thermal power, whose probes extend up to 3 meters deep if horizontal or 170 meters if vertical. However, both types are required to enter a series of data in the new telematic registers created shortly by Regions and Autonomous Provinces. Local authorities are also responsible for defining the procedures for controlling installations.

Technical requirements for residential geothermal plants

The Geothermal Probes Decree links the design of the plants to the determination of the thermal parameters of the soil by means of a thermal response test (TRT) or a survey campaign for the characterization of the subsoil. However, for installations below 50 kW it is possible to deduce these data also by resorting to evaluations and analyzes already available. For those above 50 kW there is an obligation to send the technical report with the results of the TRT or that of the survey campaign to the electronic registers. Another fundamental parameter to be respected: the carrier fluid must have a low environmental impactpreferably drinking water with the addition of propylene glycol for food use or another antifreeze. The provision also contains the technical requirements for drilling and the obligation to qualify installers.

Industry comments on the geothermal probes decree

For Archangel Francesco Violopresident of National Council of Geologists (CNG) “This is a turning point for the entire geothermal sector. This is because so far the great majority of the Regions did not have a precise reference. That is to say, it was possible to install the systems, but in a situation where one navigated in the dark about how to authorize them. For this reason, it must first of all be said that the MiTE decree is positive because it represents that signal that will finally be able to start the ‘geothermal supply chain’ and to make it become a usable resource for citizens “.

A good step forward which, however, could have aimed higher, as he explains ASS – Non-Emission Heating Association. “We fully share the value of the decree which seeks to establish a minimum level of simplification, thus starting a path of electrification of thermal consumption throughout our territory “, points out Riccardo Bani, President of ASS and on behalf of the FREE Coordination. “Unfortunately, the simplification introduced is limited to making it easier only for the construction of small and very small plants, excluding condominiums, the tertiary sector, businesses and most of the buildings of the Public Administration. We estimate that the simplification introduced in the decree will bring benefits lower than 15-20% of the achievable potential “.

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