added value:

The Scottish Executive and Scottish Water have committed to an initiative to identify and implement schemes that will accrue revenue savings by investing in capital expenditure.

Opportunities identified involve savings in energy usage, operational savings through improved process control and energy generation from renewable technologies. Halcrow is appointed as programme manager to identify and effectively implement schemes. A number of key process improvement ‘drivers’ have been agreed as follows:

• Pump efficiency improvements
• Process control improvements in particular Dissolved Oxygen Control
• Sludge digester efficiency improvements
• Instrumentation upgrading
• Automation and telemetry
• Microhydro strategy – opportunities and locations
• Wind power strategy – opportunities and locations
  

Seventeen projects, involving over 100 sites, have been identified. Halcrow progressed business case development, programming and planning of the schemes to ensure effective delivery and matching of the spend profile.

Halcrow responsibility includes undertaking the study and engineering works as well as managing other consultants undertaking these duties.

Innovation:

Renewables: implementation of renewable energy systems concentrating on wind, micro-hydropower and biogas combined heat and power (CHP) schemes. This includes site identification, feasibility assessments, detailed resource evaluation, design and project management.

Hydro: Two micro-hydropower developments are being managed by Halcrow, located at the outlet of a storage reservoir and at a break pressure tank. Power ratings for these installations are 275kW and 140kW. Both schemes benefit from having existing civil structures available to house equipment, therefore minimising development costs.

Biogas CHP: This has included detailed feasibility studies for two sludge digester CHP schemes at wastewater treatment works, including full consideration of the operational/process issues and cost-benefit analysis. 300kW and 100kW plants have been proposed, with the majority of the energy generated to be used for site loads.

Name of author: George Milne