This paper describes a 1 to 3.5 kWe hermetic scroll expander generator modified from a standard hermetic compressor, an organic Rankine cycle test facility built to test expanders up to 10 kWe and a set of experimental results using HFC 134a in the dry vapor domain. Peak overall isentropic efficiencies in the range of 63 to 65% for speeds of rotation varying between 2400 and 3600 rpm are reported. Performance is fairly constant in the range of pressure ratios considered (2.4<PR<4.0).