About this good practice
The main aim of the presented Good practice is the replacement of old oil-boilers systems and the installation of an innovative paraffine based lantern heat storage and connecting the cultural heritage building to the existing geothermal heating grid.
Municipality of Lendava has installed a paraffin-based latent heat storage in the local library building. At the same time, the library is connected to the geothermal grid.
The library is a profane building heritage. It is written in the Decree on the proclamation of cultural monuments of local importance in the area of Lendava. It is a ground floor, neo-Baroque villa with elements of secession from 1906.
The main challenges that led to the decision of Paraffin wax storage were the location of the building, cultural protection and limited space for storage. The building has been connected to the Geothermal district heating system and is the last connection in the network. It has shown that the inlet temperatures will be too low to sufficiently heat the building in the normal intermittent heating mode. Insulation of the façade would lower the energy demand but as it is a protected historic building, there are restrictions on EE measures. Energy storage offers a solution but in the boiler room it is not enough room space to install conventional water storage tanks. Paraffin storage offered a solution for this challenges.
- Municipality (Lendava)
- Ministry of Infrastructure
- Technology providers
Total investment was 96.356,99 EUR (of which the amount for the thermal substation is EUR 35,291) (co-financed by Interreg Central)
One year of planning phase (permits, documentation, public procurement) and one month of construction work.
Evidence of success
- Increase of energy efficiency: 5,5% or 3 MWh;
- Integration of political decision makers/public sector in the development and implementation process of the pilot project – as a basis for further promotion of the project to other sectors and integration of measures into the policies;
- Reduction of CO₂: 16,8 tons of CO₂ (geothermal energy has an CO₂ emission factor of “0”);
- Exploitation of renewable energy – geothermal energy: 57 MWh (savings related to energy storing included).
Potential for learning or transfer
-Paraffin wax is an excellent material for storing heat
-Paraffin cells are innovative buffer storage that have been developed to efficiently store heat and cold generated from small irregular energy sources such as solar energy, heat pumps...
-The ratio between size and capacity when comparing paraffin and water storage is more favorable for paraffin storage
-Low temperature of changing the aggregate state
-Max energy loading capacity in relation to the temperature regime.
Applicability and advantages for a Municipality:
-It can be used in connection with district heating where the challenge is to provide an adequate flow temperature
-Good possibility where we have limited room space as paraffin storage requires less room space
-Good solutions for historic buildings where there are usually restrictions on possible interventions.
-Existing heat source: preferably solar heating or heat pumps;
-Room space: Paraffin storage requires less space than water storage.