Energy storage can balance heat and power demand and production over different time scales with both technical and economic benefit. In many countries, the night-daylight range of energy price is not large anymore, but energy storage can improve the power network design and managing. Even grid-connected plants, if based on stochastic renewable sources, require care in energy dispatch and money may be saved if power lines can be sized for average or at least for values less than maximum. Several energy storage systems are proposed and discussed in open literature, but only two are really utilized: hydro-pumped storage for big size plants and battery energy storage for medium and small plants. Here, a different approach is considered, namely an Auxiliary Compressed Air Energy Storage (ACAES). It consists of a reciprocating compressor and an airtight reservoir, which can supply an additional amount of air to a gas turbine. Unlike the two well-known existing CAES plants, Hunthorf (Germany) and Mac Intosh (United States), turbo-compressor and turbo-expander are not decoupled in time. During the “charging” phase, the reciprocating compressor pumps air into the reservoir; during the “discharging” phase, the turbo-expander is fed by both the turbo-compressor and the reservoir in parallel. The turbo-compressor is partially relieved and power plant improves for the same fuel, or fuel can be saved for the same power. Of course, the energy utilized by the reciprocating compressor cannot be completely compensated: as for every storage device, storage efficiency is less than unity. This paper focuses on a standalone small size user served by a power unit that consists of an array of photovoltaic panels coupled with a commercial heat recovery cycle micro gas turbine. The aim is to lay down rules for a proper storage managing. The plant behavior is simulated by means of in-house, lumped parameter, quasi-steady codes. The storage period is selected one day and different scenarios are considered in terms of weather and user power pattern. The time history of several significant cases is reported and discussed in detail.


Compressed Air Energy Storage for a Small Size Standalone Plant Powered by a Solar Power Unit and a Gas Turbine

Division / Sponsor:
International Gas Turbine Institute (IGTI)

Paper Proceedings: https://asmedigitalcollection.asme.org/GT/GT2020/volume/84058

Turbo Expo - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.