SBIR-STTR Award

The proposal objective is to develop a flywheel energy storage system capable of achieving its maximum theoretical specific energy density, while being capable of repeated high peak-power demands. The key to achieving this objective is the development of a composite hub capable of supporting an optimized high-speed composite rim. A flywheel offers significant advantages for short duration peak loads, multiple cycles, deep discharges and rapid recharges. Under these conditions, the batteries energy/weight ratio will be significantly less, possibly less than half of the 130 watt-hr/kg, where as the flywheel's energy to weight capacity would remain constant under these same conditions. Initial calculations indicate the maximum theoretical specific energy density that the proposed flywheel could obtain is approximately 110 watt-h/kg using a high modulus carbon fiber for the composite rim in conjunction with a composite hub instead of our standard commercial grade carbon fiber rim and metallic hub currently design, which is purely cost driven.

The overall objective of the proposed program is to develop the preliminary design for the highest-possible energy-density flywheel energy storage system within the given constraints. This Phase II program plan is presented assuming that the power and energy requirements of the selected system are such that limited technology development is planned. The program is focused on trade-offs, design, and analysis leading to a Preliminary Design Review (PDR). This will be presented at a level of detail sufficient to allow a merit decision based on whether to proceed to the proto-qualification stage in Phase III.

Keywords:
FLYHWEEL ENERGY STORAGE SYSTEM, COMPOSITE HUB, ENERGY DENSITY