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Title: Third Generation Flywheels for electric storage

Technical Report ·
DOI:https://doi.org/10.2172/932894· OSTI ID:932894

Electricity is critical to our economy, but growth in demand has saturated the power grid causing instability and blackouts. The economic penalty due to lost productivity in the US exceeds $100 billion per year. Opposition to new transmission lines and power plants, environmental restrictions, and an expected $100 billion grid upgrade cost have slowed system improvements. Flywheel electricity storage could provide a more economical, environmentally benign alternative and slash economic losses if units could be scaled up in a cost effective manner to much larger power and capacity than the present maximum of a few hundred kW and a few kWh per flywheel. The goal of this project is to design, construct, and demonstrate a small-scale third generation electricity storage flywheel using a revolutionary architecture scalable to megawatt-hours per unit. First generation flywheels are built from bulk materials such as steel and provide inertia to smooth the motion of mechanical devices such as engines. They can be scaled up to tens of tons or more, but have relatively low energy storage density. Second generation flywheels use similar designs but are fabricated with composite materials such as carbon fiber and epoxy. They are capable of much higher energy storage density but cannot economically be built larger than a few kWh of storage capacity due to structural and stability limitations. LaunchPoint is developing a third generation flywheel — the "Power Ring" — with energy densities as high or higher than second generation flywheels and a totally new architecture scalable to enormous sizes. Electricity storage capacities exceeding 5 megawatt-hours per unit appear both technically feasible and economically attractive. Our design uses a new class of magnetic bearing – a radial gap “shear-force levitator” – that we discovered and patented, and a thin-walled composite hoop rotated at high speed to store kinetic energy. One immediate application is power grid frequency regulation, where Power Rings could cut costs, reduce fuel consumption, eliminate emissions, and reduce the need for new power plants. Other applications include hybrid diesel-electric locomotives, grid power quality, support for renewable energy, spinning reserve, energy management, and facility deferral. Decreased need for new generation and transmission alone could save the nation $2.5 billion per year. Improved grid reliability could cut economic losses due to poor power quality by tens of billions of dollars per year. A large export market for this technology could also develop. Power Ring technology will directly support the EERE mission, and the goals of the Distributed Energy Technologies Subprogram in particular, by helping to reduce blackouts, brownouts, electricity costs, and emissions, by relieving transmission bottlenecks, and by greatly improving grid power quality.

Research Organization:
Launch Point Technologies, Inc
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
DOE Contract Number:
FG36-05GO15163
OSTI ID:
932894
Report Number(s):
DOE/GO/15163-F; DOE Power Ring; TRN: US200821%%35
Country of Publication:
United States
Language:
English