Better Control Saves Water and Energy

Västerås and its surroundings consume 42 million litres of water every day, year-round. This means approximately 450 litres of water per second to purify and pump into the population’s kitchens, bathrooms and garden hoses. All waste water must be treated in plants before it is returned to the environment. All in all, MälarEnergi pumps water through a 600km supply network.

“Electricity costs are a major item of expenditure for us,” says Pernilla Widén, head of MälarEnergi’s water treatment plant. “A huge amount of pumping is needed to drive all the water through the network. For this task, now we employ a range of pump sizes together with a monitoring system and static frequency converters to ensure that the right pumps are always working with the right efficiency."

Previously, the pumps in the treatment plant were either on or off. Today, they are in action all the time, but output is controlled to match the needs of the pumping process exactly. 

This not only saves electricity, but because they are subjected to less wear, the pumps require less maintenance, which also saves on costs. MälarEnergi expects to save approximately USD28,000 per pump per year, an investment that should pay for itself in two to three years.

Widén said a major challenge was to install the new control and monitoring system on a fully operational water network. The new system means the water supply works, pumping stations and treatment plant will be able monitor each other, which has many advantages. 

MälarEnergi utility provides heat, electricity, water and broadband solutions plus related services for the region’s 130,000 inhabitants.

ABB control and monitoring technology is helping a Swedish utility reduce water losses, lower its electricity bills and improve water quality for 130,000 customers. Göran Vikergård, pictured, is responsible for MälarEnergi's tap water production.