Rising energy costs and the need to identify cleaner methods of energy generation have resulted in a greater focus on renewable energy systems based on solar, biomass, wind, etc. In addition, parallel efforts have focused on improving the efficiency of electric power generation. These parallel efforts include development of high efficiency fuel cell systems and the reuse of waste heat normally thrown away by industrial or commercial processes to generate additional heating, cooling or electricity using thermally driven technologies. As an example, recent advances in our Organic Rankine Cycle (ORC) technology have resulted in a system capable of generating electricity from geothermal energy sources at temperatures as low as 90 C. This system offers a low cost solution to produce electricity from a waste stream that is otherwise difficult to utilize.

On the renewable energy front, the past few years have seen the development of high efficiency photo voltaic (PV) cells and related PV system efficiency improvements. However, the high cost of these systems still remains an area of concern. A more cost effective short term solution is solar thermal based electric generation. This technology has been demonstrated on utility scale and is slowly gaining acceptance due to the cost advantage over PV cells (~$5/W for solar thermal vs ~ $8/W for PV). Further cost reduction through system simplification and increase in working fluid temperatures could result in aggressive market penetration. UTC has been working with partners to develop simpler non-tracking solar thermal collectors that may help raise the working fluid temperatures to 150 C without the need of solar tracking.

Leveraging advances in solar thermal and ORC technologies, we are investigating a system that utilizes solar and waste heat sources to provide the thermal energy needed by our ORC electric power generation system. This system is expected to operate at an efficiency of 10% with a 150 C source derived from the novel non-tracking solar collector and available waste heat. In one application, the waste-heat is expected to be provided by a fuel processing system capable of producing hydrogen (for downstream use by a fuel cell or as part of a hydrogen infrastructure initiative). Alternatively, the waste-heat could also be provided by biomass and other sources. This paper and presentation will present an overview of this system, current status, and key preliminary results related to system performance & economics. Efforts related to other zero net energy technology initiatives at UTC will also be discussed.