A new type of air-source heat pump, known as the low-temperature heat pump (LTHP), is making its second attempt at a market entry. Initial indications show that it can maintain its rated heating capacity down to temperatures as low as 0° Fahrenheit. Conventional air-source heat pumps typically operate at half or even less of their rated capacity at that temperature and have to resort to using backup resistance heat. The LTHP is also more efficient than its conventional predecessors. Despite the technology’s impressive cold-weather performance, LTHP manufacturers have several challenges to overcome. In this report, we’ve assessed the LTHP’s potential for solving numerous problems for both electric utilities and heat pump owners. (ER-06-15; December 2006; 16 pages)