Abstract: To examine the effects of regeneration on the performance and economics of a dual-heat-source organic Rankine cycle (ORC), mathematical models of non-regenerative and regenerative ORC systems were developed. The thermodynamic, exergy, and economic performance of R1233zd(E), R245ca, and R245fa was compared under varying heat-source temperatures and flow rates. The results show that regeneration mainly changes the heat-load distribution. Under varying high-temperature heat-source temperatures, regeneration reduces the external heat load of the preheater by 63–176 kW. Regeneration also changes the exergy-efficiency response. As the high-temperature heat-source temperature increases from 195 °C to 230 °C, the exergy efficiency of the non-regenerative R1233zd(E) system decreases from 47.12% to 44.93%, whereas that of the regenerative system increases. When the low-temperature heat-source temperature increases, the decline in exergy efficiency is smaller for the regenerative system. At the endpoints listed in Table 4 and for the specified equipment investment intensities, the electricity production cost (EPC) of the regenerative system is approximately 0.14–0.19 US cents/kWh higher than that of the non-regenerative system. At an electricity price of 0.0836 USD/kWh, the minimum equipment-based simple payback period is 3.89 years.