A World Overview of the Organic Rankine Cycle Market

The Organic Rankine Cycle (ORC) technology is a reliable way to convert heat into electricity, either for renewable energy applications (biomass, geothermal, solar), or industrial energy efficiency. ORC systems range from micro-scale (a few kW) for domestic cogeneration to large multi-megawatt geothermal power plants. After a slow initial start, the technology has experienced a much stronger development since the 1970s, mainly because of economic incentives and surging energy prices. However, the large range of applications, manufacturers, and countries make it hard to track the evolution of the technology over the world. Information about more than 700 projects has been collected, cross-validating 27 manufacturers' data with publications and testimonies, allowing to build the first reliable and exhaustive database of ORC plants. As a result, this work analyses the evolution of the ORC market over the years, with today 2.7 GW of cumulated installed capacity. After introducing the ORC technology with a focus on its history, working principle and main applications, the current state and the new trends of the ORC market are presented with a detailed analysis of each application. The evolution of each market is discussed considering the present installed capacity, historical data and macro-economic trends. Finally, future perspectives and growth potential of the ORC market are evaluated, with a special focus on Waste Heat Recovery applications

Thermo-Electric Energy Storage involving CO 2 transcritical cycles and ground heat storage

International audienceMulti-megawatt Thermo-Electric Energy Storage based on thermodynamic cycles is a promising alternative to PSH (Pumped-Storage Hydroelectricity) and CAES (Compressed Air Energy Storage) systems. The size and cost of the heat storage are the main drawbacks of this technology but using the ground as a heat reservoir could be an interesting and cheap solution. In that context, the aim of this work is (i) to assess the performance of a geothermal electricity storage concept based on CO2 transcritical cycles and ground heat exchanger, and (ii) to carry out the preliminary design of the whole system. This later includes a heat pump transcritical cycle as the charging process and a transcritical Rankine cycle of 1–10 MWel as the discharging process.A steady-state thermodynamic model is performed and several options, including heat regeneration, two-phase turbine and multi-stage design, are investigated. In addition, a one-dimensional model of the ground exchanger is performed and coupled to the thermodynamic model to optimize the number of wells for the ground heat storage.The results show a strong dependency between the charging and discharging processes and indicate how the use of heat regeneration in both processes could be advantageous. The results also measure the difference in performance between the basic and the advanced designs