Geothermal at a Nursery in Burgas
Overview
Geothermal installations are increasingly in demand, particularly in public buildings, as they allow cities and governments to demonstrate their commitment to reducing greenhouse gas emissions. Utilizing geothermal heat pumps increases the share of renewable energy, as demonstrated in a project for a nursery in Burgas, Bulgaria. The so-called Nursery No. 3 can host 190 children and was built in the 1960s. Its former heating system had exhausted its resources and was still using natural gas and diesel water to heat the building. The main objectives range from reducing consumption of traditional energy, reducing carbon emissions but also to increase energy security in the municipality. Geothermal heating and cooling effectively contributes to reaching those objectives. The project is supported by knowledge exchange between the local municipality and a Norwegian partner: Norsk Energi.
In Summer 2023, the geothermal energy system was officially presented, first to the locals and then to the press accompanied by a ceremony sharing newly gained benefits such as costs savings with the staff and children of the nursery. The city plans to expand the geothermal installation to all nurseries due to the need for heating or cooling all year round, especially during the hot summer months.
Technical Data
The installation includes 22 boreholes, each reaching a depth of 100 meters, with temperatures between 5 and 23 ºC. Two heat pump units supply heating, and modern coil units are installed in the rooms. The heating capacity is at 85,8 kW and the cooling capacity at 66kW which covers the heating and cooling demand of the building next to domestic hot water supplies. The heat pump units are supplemented by a heat carrier set of 45/40ºC and a cold carrier of 12/17ºC. The estimated production of geothermal energy is at 234,424 kWh per year, which reduces CO2 emissions by 276.61 tCO2. Above the boreholes, a playground for the children has been built with a shock absorbing rubber surface.
Financial Background
The total project budget is 543.345,45 BGN of which Norsk Energi covers 51.027,6 BGN and the municipality of Burgas covers the remaining costs. Additionally, the project received funding from the Renewable Energy, Energy Efficiency, and Energy Security Programme under the Financial Mechanism of the European Economic Area (2014–2021).
Summary
Technology: Open loop
Commissioning: 2023
CO2 savings: 276.61 tCO2 per year
Well depth: 100 m
Temperature: 12-40 ºC
Heated surface: one nursery
Electricity production: 234,424 kWh/y
Heating capacity: 85,8 kW
Cooling capacity: 66kW
Budget: 543.345,45 BGN