ABB drives reduce swimming pool energy costs by £60k p.a.

By installing ABB variable speed drives on filtration pumps and air handling units at five of the City’s swimming pools, Liverpool City Council is saving £60,000 a year on energy costs.

Faced with rising energy costs and pressure to manage the Recreation budget, the council approached their ABB authorised value provider for help in cutting the energy use at its swimming pools.

Energy report recommendations

The council’s maintenance manager says: “We had an energy conservation report done on one of our pools by an independent company which had recommended ABB variable-speed drives.”

The two filtration pumps were originally run in a duty/standby configuration. Pumping rates were increased as more people entered the pool. A modified pumping scheme was proposed with the pumps operating in parallel as a way to reduce energy use.

Parallel pumping

At first the council was sceptical of the proposed scheme, so a trial was agreed to prove the viability.  Before installing the two new ABB drives, energy use of the pumps was monitored and flow rate or water pressure recorded.  Savings of 10-15% had been suggested, but logging the energy use it was  found the drives made a 35 percent saving under the same operating conditions, with a payback of around six months.

Following the installation of the drives, low occupancy switches were also installed to reduce the motor speeds further when fewer people were using the pool or when the pool is closed.  A frequency  of 45 Hz, was planned but can go as low as 30 Hz.

Since the initial installation, ABB drives have been retrofitted into four other swimming pools, for water pumps and air handling units. With a total of 20 drives over the five sites ranging from 7.5 to 18 kW, the project is saving £60,000 a year, with a payback of around two years.

999 Inverters sells ABB drives at discounted prices here