Strategic Energy Factory Partner Study

In 2008, Sweco Netherlands led the research to develop the Energy Factory concept as part of the ‘Energy Factory of Waterschap Aa en Maas’ Consortia. The concept was in response to the Dutch Government’s challenge to Water Boards to utilise more sustainable assets and to deliver 30% improvements in energy efficiency and 40% energy self-generation by 2020. The concept utilises the energy potential within the wastewater influent to develop treatment plants into energy positive sites.

Key Facts

Client: United Utilities
Contract Value: £270,000


Site surveys
Concept studies
Economic Analysis
Carbon footprint assessments
Innovative Technology Assessment


In 2012, the Energy Factory concept was rebranded as ReGenerator® Factory concept to include:

  • Energy Factories
  • Nutrient Factories
  • Water Recovery Factories

In the UK, the ReGenerator concept is an approach championed by Sweco to provide more choice for our clients by assessing wastewater treatment works from an operational cost perspective and applying this assessment to create an optimum TOTEX solution.

Project Description

United Utilities (UU) were seeking additional choices for solving a tighter Ammonia consent standard at Davyhulme WwTW. Sweco provided a ReGenerator solution for the site that utilised different European treatment technologies that were outside UU’s current Asset Standards. The project demonstrated the potential of the ReGenerator approach and Sweco were subsequently appointed as UU’s Strategic Energy Factory Partner.

We were commissioned to assess 28 of UU’s major wastewater treatment works. The objective was to assess the maximum potential operational savings via the introduction of new treatment technologies. The study included site surveys at 5 sites: Crewe, Leigh, Blackburn, Bolton and Birkenhead which corresponded to 5 different generic types of wastewater treatment works found in UU’s estate. The site surveys were used to create our ReGenerator solutions which were then repeated for the remaining 23 sites. The assessments which included energy consumption reduction, energy production and surplus thermal energy re-usage enabled Sweco to build a 15 year economic model to analyse the potential benefits for the sites.


Our solutions included enhancements to primary settlement using the Adsorption and Bioxidation (A/B Stage) treatment process together with DEMON® for side stream liquors treatment, energy self-sufficiency by DEMON® (EssDe) in the Activated Sludge plant, Thermal Hydrolysis Plant (Eliquo’s Lysotherm® treatment process) and additional CHP capacity.

The assessments showed UU that they could half the consumption and double the production of electricity across their wastewater treatment estate. The majority of the sites could also generate surplus thermal energy which, by supplying low grade heat to third parties, could become an additional revenue stream.

UU have utilised the ReGenerator solutions for a number of schemes, which is in line with their target to achieve ‘energy neutrality across their wastewater works by 2020’.