Saving £100,000/year

Northumbrian Water is set to save £100,000 a year on pump running costs following a project with ABB Drives Alliance member, Quantum Controls, to install ABB low voltage AC drives on its anaerobic digester tanks.

Quantum Controls fitted two low voltage AC drives to one of the tanks. As well as giving the ability to reduce motor speeds, avoiding foaming of liquid in the tank which interfered with the volume of methane being produced, it demonstrated a cost saving through the reduction of the energy used by the motors. Quantum Controls measured the difference in power between two pumps running simultaneously, with the first pump being star-delta and the second being controlled by a low voltage AC drive.

Quantum Controls calculated overall savings of £107,000, giving a payback period of 0.27 years.

Northumbrian Water will also be able to reduce its CO2 footprint by over 700 metric tons a year, giving an extra saving of £8600 under the UK carbon tax credits scheme. This brings total savings to £115,000; return on investment is 92 days.