Geothermal electricity plant in Velika Ciglena
Overview
In 2019, Croatia joined the growing group of countries with geothermal electricity production when the Velika Ciglena Geothermal Plant started operations as the first of its kind in the country. When it was commissioned, it was the largest Organic Rankine Cycle (ORC) geothermal plant in Europe with a capacity of 17.5 MW.
The region of Velika Ciglena is located near Bjelovar in the north-east of Croatia. The geothermal reservoir had been known since 1990 when explorations for oil were carried out. No oil was found but instead the geothermal potential of the region was discovered.
Electricity production
Since it started zero-emission power production at full capacity in March 2019, the Velika Ciglena plant can supply almost the entire city of Bjelovar (population 36,000) with electricity. The electricity is fed into the power grid and a power purchase agreement with the Croatian Energy Market Operator is in place for 10 MW of installed capacity, which corresponds to the consumption of 29,000 households.
Investment and local jobs
The power plant was built by the Turkish company MB Holding that already has experience with geothermal power plants in Turkey, and the Italian turbine manufacturer Turboden. The eotal investment amounted to HRK 325 million (around EUR 43.7 million). Out of this investment, more than 68% was spent on materials, equipment or services by domestic suppliers and contractors with 15 local companies working on the power plant during the two-year construction period. With the commissioning of the plant, 10 new jobs were created for the local community.
“A project like this can only be built with a lot of enthusiasm and investment. The fact that more than HRK 300 million has been invested describes how much investors believed in the project and how skilled this team is. Croatia has its interest in every kW and that is why projects like this need to have broader support. [...] Our task is to establish a framework that will encourage investors to invest, so that the potential of renewable energy sources can benefit us in the long term and create the basis for energy sustainability”
Technology
The Ciglena plant has two production and two reinjection wells which were drilled into a reservoir at a depth of about 2800 meters. The geothermal brine with a temperature of 170°C is pumped to the surface and passes through a heat exchanger with the ORC. In this way, the geothermal brine can be fully reinjected into the reservoir and the steam powering the single turbine does not lead to corrosion. In 2016, the Velika Ciglena project received the Best Innovation Award for its innovative design by Mitsubishi Heavy Industries.
For more information on the functioning of the power plant, watch this video by ORC manufacturer Turboden.
Summary
Power plant capacity: 17.5 MW
Produces enough electricity to supply almost the entire city of Bjelovar with 36,000 inhabitants
Two production and two injection wells with a depth of about 2800 m
Commissioned in 2019
Best Innovation Award for its innovative design in 2016
Sources:
Completed the commissioning of the Geothermal Plant | TURBODEN
Turboden - 17.5 MW ORC geothermal power plant in Velika Ciglena - YouTube
Croatia’s First Geothermal Power Plant Velika 1 Has Been Officially Opened - OIE
Croatia’s first geothermal power plant Velika 1 officially unveiled (balkangreenenergynews.com)