New geothermal district heating system in Tuscany, Italy

Date: 17 November 2014

The geothermal district heating network sources steam from the Enel Green Power high-enthalpy Montieri 4 well with a total of 425 heating units will be served by the system, representing a total volume to be heated of about 111,000 m3.

Local italian sources report that a new geothermal district heating system has started operating in the Tuscan village of Montieri, province of Grosetto, courtesy of the European GeoCom project which aimed at completing three demonstration sites to highlight the benefits of geothermal energy in energy efficiency and renewable energy. The three sites are Montieri in Italy, Galanta in Slovakia and Mórahalom in Hungary.

The Montieri site included the creation of a geothermal district heating network, upgrading the energy efficiency of public buildings, and installation of solar PV panels and LED globes for street lighting, and solar thermal panels to provide space heating and domestic hot water for those households unable to connect to the district heating network.

The geothermal district heating network sources steam from the Enel Green Power high-enthalpy Montieri 4 well at 15-20 bara and 200-215 °C flowing at 50-60 tons per hour. A total of 425 heating units will be served by the system, representing a total volume to be heated of about 111,000 m3 and requiring about 20,000 GJ or 5,500 kWh of heat energy. The public lighting system uses 8.5 kW of solar PV panels while 42.5 m2 of solar collectors are used for the outlying domestic hot water services.

A challenging part of the project has been retro-fitting the historic houses and buildings of medieval Montieri village. This has required a high level of care for the town’s high cultural and artistic value, in particular the full reconstruction of narrow paved streets containg the water supply and drainage pipes. The distribution network is about 5,600 m long and uses two heat exchange circuits to firstly transfer heat from the well 170 m up to the town at 700 m above sea-level, and secondly through the town. The secondary circuit supplies water at 80-90 °C to households.

Residents are able to heat their homes free of charge from the new system until the end of December.

Source: Volcanex