During ancient time, the Romans and Turks used hot water springs to heat their baths and homes, and with time its use grew such that by the 19th century steam and hot water reservoirs beneath the earth's crust were being tapped for heating entire districts in cities.
Using the heat from the earth
Geothermal energy, literally translated as heat from the earth - is now emerging as a preferred energy source due its extremely low carbon footprint. Also, technological advances in process control and drilling have made it easier and more viable to harvest.
The advantages of Geothermal energy is that it can be harvested without burning any fossil fuel, thereby having practically no greenhouse gas emissions. Unlike solar and wind energy which are dependant on weather and sunlight hours, geothermal energy is available 365 days a year, 24 hours a day.
Wells several thousand meters deep are drilled beneath the earth's surface to tap the heat, and then, water is injected through the cracks made. A production facility is used to pump up the steam that is generated and a mechanical system delivers the heat directly for its intended use. Afterwards cooled water is re-injected into the ground to produce more steam. From drilling, injecting water, to pumping and distributing steam all procedures require high levels of precision, monitoring and control.
Hungary's most potential geothermal water sources
Located in the Pannonian Basin, the city of Szeged is considered one of the most potential geothermal water sources in Hungary. In the year 2011, geothermal-sourced district heating was identified as the energy-efficient and cost-effective method for heating residential and government buildings in the city.
To use these resources for the new district heating system, Geothermal Services Ltd. company, decided to drill 2 wells (2,000 m each) along with 2 re-injection wells (1700 m and 1250 m) deep into the geothermal reservoirs along with the pipeline network to provide a steady stream of hot water. Once commissioned these wells will heat up several large communal buildings including clinics, schools, colleges, libraries, and sport halls, etc.
A tender was commissioned for the turnkey engineering and supply of automation, instrumentation and electrical scope for this project. After a long bidding process against other leading vendors, ABB's Process Automation team in Hungary was selected as the winner.
Phase 1 of the district heating system is in operation since November 2013, providing heat for 25 large municipal customer during the wintertime.