Low temperature "Carnot battery", using waste or geothermal heat and an Organic Rankine Cycle
A “Carnot battery” for electricity storage comprises a thermal storage, a cooling facility, a heat pump and a power generator. Electricity is consumed by the heat pump supplying heat into the storage. Upon demand, electricity is produced using heat. The “battery turnaround efficiency” of a Carnot battery is dictated by the efficiencies of the power cycle and the heat pump and is typically between 30-60%.
A demonstration project by Climeon, KTH (Royal Tech. Highschool Stockholm) and RISE (Research Institutes of Sweden), partly financed by the Swedish Energy Agency (2016-2017), is presented. Heat is produced using a heat pump capable of producing 85-95 degC water, utilizing industrial waste heat as heat source. Electricity is produced, time-shifted, using Climeon’s low pressure ORC. The presentation covers demonstration project results and learnings, heat pump and storage options, application fields, LCOS (levelized costs of storage) and an outlook on likely future projects.
Joachim Karthäuser is CTO of Climeon AB. Following studies of chemistry at Aachen and Göttingen University and his Ph.D. work on combustion chemistry, he joined Shell Chemicals in 1989 and worked internationally in R&D, technology and sales. After further spells at NKT in Denmark (2000-2003) and AGA/Linde Gas in Sweden (2003-2006), he started clean-tech companies (wind power, materials, CO2 cleaning). In 2011, Karthäuser co-founded Climeon AB, a company selling modular ORC power plants.