Storage of electricity from fluctuating renewable energy sources has become one of the predominant challenges in future energy systems. A novel system comprises the combination of a heat pump and an Organic Rankine Cycle (ORC) with a simple hot water storage tank. The heat pump upgrades low temperature heat with excess power. The upgraded heat can drive an Organic Rankine Process using the heat pump in reverse operation mode. This approach allows a comparably efficient storage of excess electricity. Waste heat sources usually do not qualify for electricity production even with ORC processes due to low temperatures. Upgrading the temperature of the waste heat by means of excess electricity makes the use of an ORC feasible in order to recover the electricity input. Thermodynamic cycle simulations with IPSEpro software outline that the process provides power-to-power efficiencies in a range of 50% for small-scale applications based on commercially available heat pump components. The isentropic efficiency of compressors/expanders plays a crucial role on the system performance. Applications of the proposed cycle in the megawatt range with more efficient turbines and dynamic compressors will therefore increase the power-to-power efficiency to above 70%.

CO₂ is the main determining factor for global climate change. For this reason, the emissions of this gas have to be reduced as much and as quickly as possible. This paper discusses the possibility to realize a CO₂-neutral heat and power supply for single and multi-family homes. There have been a lot of studies in the past, as well as several unsuccessful-attempts to commercialize such a system. However, this paper presents a new and simple 1 kW_el setup for a smart combined heat and power (CHP) plant offers solutions for the deficiencies of previously published and demonstrated systems. A commercial pellets firing system is linked with an organic Rankine cycle (ORC), which is built with mass-produced parts. In addition, inexpensive and proven-in-use hot-water storage tanks are used as an energy buffer and for storage, resulting in reduced investment costs. Furthermore, we demonstrate that it is necessary to embed such a system into a smart home environment in order to achieve an efficient and profitable setup.