Heating is a major requirement in many regions, and growing energy demands and pollutant emissions have allowed unconventional heating technologies to be considered, including geothermal. Geothermal heat pumps are reviewed, including heat pump technology, earth connections, current world status...

Many factors to be appropriately addressed in moving towards energy sustainability are examined. These include harnessing sustainable energy sources, utilizing sustainable energy carriers, increasing efficiency, reducing environmental impact and improving socioeconomic acceptability. The latter...