In the interests of environmental protection, the reduction of CO2 emissions is increasingly becoming an important issue and relevant cost factor. This can be shown using a simple example. Here the CO2 emissions of the two versions oil-fired heating/air-cooled refrigerator unit und ground-source heat pump/refrigerator unit are compared. The complete supply chain is considered from the harnessing of primary energy through to energy utilisation in the building since all the preceding stages contribute to the overall environmental impact.
Based on the energy flows, energy consumption and CO2 emission values, reductions in CO2 emissions of 80% to 90% are obtained.
Chart - Reduction in CO2 emissions (example):
The return on investment will depend on a whole series of factors:
Solutions will vary according to the extent to which thermal energy requirements can be covered, the necessary level of investment and the achievable savings in running costs.
In most cases, the additional investment outlay is paid for by the savings in running costs within a short period of time. Major factors influencing pay-back time include energy prices, cooling requirements, the technical energy concept for the building and the geothermal energy potential which can be tapped by the foundations.
Savings in primary energy are the main reason for savings in running costs and are in the region of 80%.
The follow-on costs resulting from the CO2 emissions based on a world average were calculated by the World Bank as approx. €27 per tonne.
Chart - Cost savings (example):
Self-regenerating energy source
Low dependence on conventional power
Closed circuits preventing any risk to groundwater
Long service life
Reliable system with low space requirements - most of the piping is laid in concrete structures
