Performance characteristics

Our existing technology has been extensively tested and is fully detailed in our performance verification whitepaper. The existing flywheel technology is currently undergoing changes for new field trials and further commercial deployment. The new commercial flywheel unit offers the potential to achieve significant performance improvements over the existing flywheel including the following:

• extended DC link voltage range
• reduced volume
• higher power density
• higher energy density
• higher efficiency
• substantially lower cost

The envisioned performance characteristics of the new commercial flywheel unit are contrasted with the verified characteristics of the existing unit in the table below. The commercial flywheel unit is approximately sized for heavy duty hybrid vehicles. These performance numbers can be modulated to suit exact customer requirements.

Characteristic	Units	Existing unit	Commercial unit	% change
DC link voltage	V	600 - 750	550 - 850	N/A
Power	kW	120	120	0%
Energy	kWh	0.77	0.75	-3%
Mass	kg	150	230	53%
Volume	liters	103	70	-32%
Specific power	W/kg	800	520	-35%
Power density	W/liter	1,165	1,715	47%
Specific energy	Wh/kg	5.1	3.3	-35%
Energy density	Wh/liter	7.5	10.7	43%
Outside diameter	mm	610	400	-34%
Length	mm	460	540	17%
Average one-way efficiency	N/A	93%	97%	4%
Average round trip efficiency	N/A	86%	94%	8%

Possible arrangements for flywheel deployment

The following table shows different possible flywheel configurations for a range of applications. Note that the stated specifications are generalizations and are flexible.

Use	Arrangement	Power (kW)	Energy (Wh)	Mass (kg)	Volume (L)
Metro		1,200 (120 x 10)	7,500 (750 x 10)	2,300 (230 x 10)	700 (70 x 10)
Light rail		480 (120 x 4)	3,000 (750 x 4)	920 (230 x 4)	280 (70 x 4)
Container handling		360 (120 x 3)	2,250 (750 x 3)	690 (230 x 3)	210 (70 x 3)
Heavy duty truck or bus		120	750	230	70
Medium duty truck		120	320	130	50
Light vehicles		60	160	80	36

Our kinetic energy flywheel solutions

Our flywheel solutions are fully configurable and are available as components through to fully integrated solutions. The table below details what hardware is available in what configuration.

		Integrated systems offerings
Component	Custom component offerings	Flywheel module	Custom solution	Fully integrated solution
Flywheel rotor	X	X	X	X
Motor / generator	X
Bearing system	X
Power electronics			Optional
Control electronics			Optional
Vacuum system			Optional
Cooling system			Optional
Cabinet			Optional

Our engagement process

The following flow diagram outlines our typical engagement process. Note that various documents (e.g. PPAP, DFMEA, PFMEA) are generated with the agreement of both contracting parties. The following process is available as a download from our downloads page.