Electrical Oil Services

Electrical Oil Services (EOS) supplies recycled and unused electrical insulating oils and associated transformer services to the electricity sector and energy‑intensive industries. Established in 1999 as a 50:50 joint venture between the electrical oils businesses of Carless Refining & Marketing and Castrol UK, the business has roots in UK post‑war efforts to reclaim scarce transformer oil and has since evolved into a specialist, stand‑alone brand of HCS Group, owned by Haltermann Carless. From its operational base in Stanlow, near Ellesmere Port in the UK, and facilities in Hamburg and Duisburg in Germany, EOS serves municipal utilities, electricity transmission and distribution operators, distribution system operators, grid operators, transformer OEMs, large power plants, steel and aluminium producers, combined heat and power plants and other high‑energy industrial users across Great Britain and continental Europe. EOS’s activities span the full lifecycle of mineral insulating oils for transformers and oil‑filled equipment. It produces and markets unused and reclaimed insulating oils, including the recycled EOS Premium grade manufactured at its processing plants in Duisburg and Stanlow, which meets IEC 60296:2020 Type B and is marketed Europe‑wide. The company operates Europe’s largest fleet of Mobile Processing Units to dry, degas, filter and refill transformer oil on site, and Mobile Regeneration Units and stationary regeneration sites to deep‑clean entire insulating systems, extending transformer service life. Complementary services include insulating oil testing and diagnostics through its own laboratories and partners, PCB and condition monitoring programmes, on‑ and off‑site oil storage, oil logistics and disposal, transformer inspection, maintenance and revision, and vacuum filling and commissioning support for new transformers. EOS’s closed‑loop model collects used transformer oil, regenerates it to as‑new quality and returns it to the circular economy, supporting resource conservation, CO₂ reduction, operational safety and cost‑efficient asset management for network and industrial customers.