LU says that in the first week of operation the system recovered enough electricity to power a large underground station such as Holborn for more than two days a week. Initial results indicate that up to 1MWh can be recaptured per day for reuse elsewhere.
In addition, the system reduces the amount of heat generated by braking in tunnels, which in turn reduces the energy requirement for tunnel cooling systems.
LU calculates that the technology could enable it to reduce energy costs by up to 5% or £6m per year.
Whole-life energy costs are now considered as part of the specification for all infrastructure upgrades on the LU network.