Regenerative braking and motion recovery: Impact and additionality

Real savings, spread thinly across millions of machines

Abatement is real but spread thinly across many machines. It is largest where duty is stop-start and the energy replaced is diesel.

Direct Scope 1 and Scope 2 abatement

A diesel RTG with energy recovery could cut about 81 t CO₂ a year. Across Felixstowe's fleet of about 100 cranes that is about 8,100 t. Gyrodrive buses saved 20% of fuel in Go-Ahead trials, and GKN claimed up to 25%. On electric systems the saving is Scope 2. The Hamburg metro Hesop returned 1,042 MWh in one year, about the use of 300 to 400 European households.³⁵⁶⁷

Water and air synergy

Less friction braking means less brake dust. Lift regeneration removes resistor heat from machine rooms, which cuts cooling load. Fuel savings on diesel buses and cranes cut local NOx and particulates in proportion. No figures were sourced for these co-benefits.⁴

Avoided lock-in

Regeneration in electric vehicles, trains and lifts carries no fossil lock-in. Flywheel and storage add-ons for diesel buses and cranes can extend diesel fleets. They are best seen as a bridge for assets with several years of life left, not as a reason to delay electrification.⁶

Sources

1. Capturing wasted energy in our cities (Hesop reversible substations) (company press release) Alstom, 2025
2. ReGen drive (product brochure, UK) (vendor claims) Otis
3. Analysis of energy usage for RTG cranes (Papaioannou et al.), Energy 125, accepted manuscript Elsevier (repository copy, Manchester Metropolitan University), 2017
4. From fast lane to bus lane (GKN Gyrodrive order by Go-Ahead) Institution of Mechanical Engineers, 2014
5. Gyrodrive hybrid technology first to make economic sense to bus operators (company claims as reported) Transport Engineer