District Heating System: the experience of the City of Ferrara and the development possibilities of its network.
Topic of the practice
Municipality of Ferrara's “Geothermal Project”
Good Practice Information
In the 1960s, while a research study was investigating new oilfields, an underground source of hot water (approx. 2,000m deep) was discovered. After the energy crisis of the 70’s, the Municipality of Ferrara launched the “Geothermal Project”, to exploit the geothermal resource as a primary source for an urban heating system.
First, the geothermal fluid (hot water at 100°C) is pumped from depths of 1,000m to the surface; then the hot water transfers thermal energy to the heating system. Finally, it is re-introduced in the ground in order to ensure geotechnical stability. Now, the network in Ferrara is fed with the so-called “Integrated Energy System”, because the energy from the Waste Treatment Plant was added to the geothermal source. This practice is interesting because it combines medium-enthalpy geothermal source with the energy from the Waste Treatment Plant. This Integrated Energy System, added to a production system fed with fossil fuels (methane gas), is able to cover, when necessary, the peaks of energy demand. This type of District heating enables to satisfy the duty of installing plants that work with renewable sources as expected by D.Lgs.192/2005 and to increase the value of buildings improving the energy efficiency class as expected by National and Regional legislations (DAL 156/08).Actually, a workgroup composed by HERA, the University of Ferrara and the Emilia-Romagna Region, is studying the prospects of enhancing the system with a new geothermal source (in the opposite side of the city), a solar heating system, an ORC (Organic Rankine Cycle) system and extra boiler in case of emergency.
Evidence of success
This system has more environmental and economic benefits than a traditional heating system because it allows significant cost savings and reduction of CO2 emissions. A District Heating System, like the Ferrara’s one, in which renewable energy represents the 83% of the total, allows an energy saving equal to 57100 photovoltaic panels. In addition to the geothermal source, the development project also contains a Solar Thermal Plant and an ORC (Organic Rankine Cycle) turbine. The benefits are going to increase with the development project expected for the urban network. Based on recent studies, it has been decided to extend the existing scheme of the District Heating Network by increasing the use of renewable energy sources.
Contact details to obtain further information on the practice
Province of Ferrara
Annex completed on: 03-29-2011