A review of the water processing system at Severn Trent has seen a 65% energy saving, with only a seven month payback on the newly installed system.

A 65% energy saving has been achieved by Severn Trent following replacement of water process pumps. Three 37 kW ac drives at the company's Wanlip Sewage Treatment Works in Leicestershire were replaced following the introduction of a a new service scheme from the ABB Drives Alliance.

The Drives Advantage scheme is aimed at the water utilities and offers bespoke programmes aimed at upgrading or replacing drives. ABB Drives Alliance undertook an energy audit of the Wanlip site to determine inefficiencies in the process and recommend changes. The three drives installed replaced 20-year old units used on process pumps to push water back into the site's system for various uses. These had been proving inefficient and unreliable.

For an initial investment of under £7000, an energy saving of £10 000 per year is being saved using the ABB IP21-rated standard drives - a saving of over £46 000 over the five-year warranty period of the drives.

A further installation of the ABB drives on two aerators at the site has given annual savings of £5800 for a payback period of 11 months.

Following this project the water utility firm has set up an Energy Saving Project Group to examine the need to upgrade existing drives and install new drives through its network of sewage treatment plants.

Source

Electrical and Mechanical Contractor