17 Ground-Source Heat Pumps and Energy Saving Mohamad Kharseh Willy´s CleanTech AB, PARK 124 Karlstad, Sweden 1. Introduction The global warming itself and its consequences cause considerable problems. It results in extreme climate events such as droughts, floods, or hurricanes, which are expected to become more frequent. This puts extra strain on people and has great impact on public health and life quality especially in poor countries. Internationally, there is a political understanding that global warming (or climate change) is the main challenge of the world for decades to come. Thus, all states must work together in order to overcome climatic change consequences. Although, studies suggest that there is indeed relationship between solar variability and global warming (Lean and Rind, 2001), two causes of the warming have been suggested: 1. related to the accumulation of greenhouse gases in the Earth’s atmosphere; 2. related to heat emissions (Nordell, 2003, Nordell and Gervet, 2009). This implies that current warming is anthropogenic and caused by human activities, i.e. global use of non-renewable energy. So far, the total global energy consumption has already exceeded 15 . 10 10 MWh/year and it is projected to have an annual growth rate about 1.4 % until 2020 (EIA, 2010). Much of the energy used worldwide is mainly supplied by fossil fuels (~85 % of the global energy demand while renewable energy sources supply only about 6 %) (Moomaw et al., 2011, Jabder et al., 2011, Jaber et al., 2011). Owing to global dependence on oil fuels has resulted in a daily oil consumption of 87.7 million barrels (Mbbl), Fig. 1 (IEA, 2010, EIA, 2007). Consequently, about 3.10 10 ton of carbon dioxide emissions are annually emitted into the atmosphere. In other word, for each consumed kWh about 205 kg of carbon dioxide is being emitted into the atmosphere. Environmental reasons urge us to find more efficient ways in converting and utilizing the energy resources. From the environment point of view, there is now almost universal scientific acceptance that profligate energy use is causing rapid and dangerous changes in the global climate. There is mounting evidence that the mean global temperature has increased over the period 1880 to 1985 by 0.5 to 0.7 o C (Hansen and Lebedeff, 1987). While surface air temperature (SAT) compilations shows that SAT has increased 1.2 o C last century. If a current climatic change trend continues, climate models predict that the