Alstom to supply ground-braking energy recovery system for London Underground

Alstom was awarded a contract by UK Power Networks Services  to supply its innovative Harmonic and Energy Saving Optimiser (HESOP) energy recovery system for the Victoria Line of the London Underground. The contract, worth about 1 million, is for a trial of inverting substation technology that will run until 2014 at the Cloudesley Road substation. This will help make the Underground more energy efficient and will also help control tunnel temperatures..

The HESOP system works by converting and transferring any unused power, generated by the trains during braking, to accelerating trains elsewhere on the line or to the grid. The HESOP control system is highly intelligent and ensures that the energy is recovered via the most efficient route that the infrastructure will permit. It enables the recovery of more than 99% of the traction energy generated during braking, thereby reducing CO2 emissions through reduced energy consumption.

By using HESOP, the Tube could also become cooler because London Undergrounds tunnels are very small, meaning most heat transfer from the braking resistors stays in the tunnel walls and surroundings rather than being moved out of them by convection.

London Underground already makes good use of regenerative braking but, by adding HESOP to the power supply arrangements, the residual energy that is currently wasted in braking resistors can be made use of this will help prevent tunnel temperatures rising.

Terence Watson, Managing Director of Transport for Alstom in the UK & Ireland, said: This is fantastic news for us, for London Underground, for commuters and for the environment. We bring London Underground our innovative technology to the UK, with the introduction of HESOP. This is just the latest sign that we at Alstom are determined to become active across rail infrastructure in the UK through our various partnerships were already active in signalling and electrification, and we recently won the contract to fit out Crossrails tunnels.

A 3D animation of the HESOP system in action, which is already operational in Paris at the Pablo Picasso station on the T1 line, is available to view here.