So far the heat pump has stood in the shadows of other energy producers. That could change fast,because the device is eco-friendly and highly efficient. More and more households have turned to the new technology. The sector's growth rates are enormous. One company taking advantage is Lower Saxony-based Stiebel Eltron.Just in Germany,over 60 thousand heat pumps were sold last year - up a third on the 2007. Heat pumps function even at temperatures of -20 degrees celsius. Our reporter Sascha Quaiser visited the heating specialists at Stiebel Eltron,which reports sales exceeding €400 million annually - more than half abroad. The company employs 3,000 people worldwide. Last year because it couldn't meet demand for heat pumps,so it opened a new production facility in May. Now Stiebel Eltron can produce 60,000 units annually. The jobs are saved.