Material Insights · Understanding the Material World

Electrical loss reduction: Engineering and integration

Routine retrofits inside the switchroom, done carefully

What this tab covers Engineering and operating integration: how tightly it is coupled to the host process, how steady the waste stream is, and how hard it is to retrofit.

These measures sit inside the electrical system, so careful design matters more than process coupling. Most are routine retrofits.

Process interdependence (coupling risk)

Favourable

Capacitor banks and filters switch in steps and can be bypassed without stopping the plant, though a failed or badly tuned filter can let harmonics trip sensitive equipment. Transformer heat recovery must not block the transformer's own cooling, so the original radiators stay as backup. Regenerative drives keep a braking resistor or fall back to friction brakes if the grid cannot accept power. Active front ends remove the need for that resistor (vendor claim).61114

Load factor and intermittency

Mixed

Transformer no-load losses run around the clock. ABB's standard unit wastes about 24 MWh a year in no-load loss alone (calculated, 2.782 kW for 8,760 h). Load losses rise with the square of current, so recovered heat follows electricity demand. In the UK case study, a heat network could reuse 56 to 81% of the transformers' available heat, depending on the scenario. Regeneration happens only when drives brake, as in lifts, cranes, downhill conveyors and trains. MW-scale regenerative drives on downhill mine conveyors have been studied since at least 2002.31215

No-load loss per year, 2,500 kVA unit about 24 MWh (calculated)3 Share of transformer heat reused (case) 56-81%12

Footprint and retrofit complexity

Mixed

Capacitor banks and active filters fit into existing switchrooms during a planned shutdown. Replacing a transformer with a low-loss unit is a larger job. Regenerative drives often replace an existing drive one-for-one. Transformer heat recovery needs a heat user close by. UK Power Networks' Full Circle feasibility project (GBP 535,086, October 2023 to March 2024) looked at a Wandsworth grid substation about 200 m from a heat network energy centre. Most of the UK potential, about 58%, is in mainly urban areas.1213

Full Circle budget GBP 535,08613 Urban share of UK transformer heat potential about 58% (2.3 TWh/y)12

Sources

  1. Transforming revenue: ABB's technology cuts transformer losses (ABB Review 2/2015; vendor case) ABB, 2015
  2. ReGen drive (product brochure, UK; vendor claims) Otis
  3. Harmonics: what electrical contractors need to know, Part 2 (R. Ignall) EC&M, 2026
  4. Heat recovery opportunities from electrical substation transformers (Lagoeiro, Davies, Marques and Maidment), Energy Reports 10, 2931-2943 (open access) Elsevier, 2023
  5. Full Circle (transformer heat recovery project) UK Power Networks, Strategic Innovation Fund, 2024
  6. VLT Active Front End drive (product sheet; vendor claims) Danfoss, 2014
  7. Regenerative drives in the megawatt range for high-performance downhill belt conveyors (Rodriguez, Pontt, Becker and Weinstein), IEEE Transactions on Industry Applications 38(1) IEEE (abstract via Universidad Andres Bello repository), 2002