An overview is presented on the last decade of geothermal heating by ground source heat pumps (GSHPs) in Europe. Significant growth rates can be observed and today's total number of GSHP systems is above 1 million, with an estimate of about 1.25 million mainly used for residential space heating in 2011. These systems are counted among renewable energy technologies, though heat pump operation typically consumes electricity and thus only a fraction of the energy produced is actually greenhouse gas (GHG) emission free. Consequently, only in the most mature markets of the Scandinavian countries and in Switzerland, calculated emission savings reach more than 1% compared to standard heatings. However, Sweden shows that more than 35% is possible, with about one third of these systems in Europe concentrated in this country. Our calculations demonstrate the crucial role of country-specific heating practices, substituted heat mix and primary electricity mix for country-specific emission savings. For the nineteen European countries studied in 2008, 3.7 Mio t CO 2 (eq.) are saved in comparison to conventional practice, which means about 0.74% on average. This reveals that many countries are at an early stage with great potential for the future, but even if the markets would be fully saturated, this average would barely climb to about 30%. These numbers, however, take the current conditions as reference, and when extrapolated to the future can be expected to improve by greener electricity production and increased heat pump performance.

Greenhouse gas emission savings of ground source heat pump systems in Europe: A review

Finite line-source model for borehole heat exchangers: effect of vertical temperature variations

Addressing the growing concerns of climate change necessitates the decarbonisation of energy sectors globally. Heating is the largest energy end-use, accounting for almost half of total energy consumption in most countries. This paper presents an extensive review of previous works on several aspects of heat pumps, including their role in the decarbonisation of the heating sector. In addition, themes related to recent technological advances of heat pumps, as well as, their roles in terms of adding flexibility to renewable-rich systems and carbon abatement are examined. Challenges and barriers facing large-scale deployment of heat pumps are identified. Generally, as the share of renewables in the energy mix increases, heat pumps can play a role in addressing a multitude of problems induced by climate change. The potential of heat pumps to abate emissions, however, is highly dependent on the type of technology, location and electricity mix. Heat pumps can be a source of flexibility in the power system and can upgrade waste heat to provide low-cost heating in district heating networks. They are environment friendly and provide a viable pathway for decarbonising the heating sector. However, economic, regulatory, structural and infrastructural barriers exist, which may hinder heat pump integration rate.

Heat pumps and our low-carbon future: A comprehensive review

Experimental and modeling analysis of a ground source heat pump system

Ground source heat pumps as high efficient solutions for building space conditioning and for integration in smart grids

Comparison between the energy performance of a ground coupled water to water heat pump system and an air to water heat pump system for heating and cooling in typical conditions of the European Mediterranean coast

H. Witte

Papers

Comparison between the energy performance of a ground coupled water to water heat pump system and an air to water heat pump system for heating and cooling in typical conditions of the European Mediterranean coast