2009-12-11 - MälarEnergi is a large, municipally-owned energy company in the Mälardalen region of central Sweden. It is the sixth most populous municipality in Sweden, and the country's fifth largest urban area. Its principal city is Västerås.
By ABB Communications
MälarEnergi utility provides heat, electricity, water and broadband solutions plus related services for the region’s 130,000 inhabitants.
For tap water production, a new ABB control and monitoring system guards water quality, energy consumption and water losses, ensuring potential profits aren't poured down the drain. Before the upgrade, MälarEnergi's water network lost more than 30 percent of its water.
Västerås and its surroundings consume 42 million liters of water every day, year-round. This means approximately 450 liters 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 600 km-long supply network.
Payback in two to three years
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, above, is responsible for MälarEnergi's tap water production.
“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, about one third of the water we produced disappeared, which meant that we could not charge for it. Now our objective is 20 percent."
Göran Vikergård, MälarEnergi
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 $28,000 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 uses a control and monitoring system based on ABB’s versatile and dependable AC800M controller, which helps control losses and even helps improve water quality, explains Göran Vikergård, responsible for the utility's tap water production.
“Just consider leaks,” says Vikergård. “A 600-km long water-tight seal is almost impossible to achieve, so we always have to live with some leaks. But now that we have new water meters and pressure gauges throughout the whole network, we can locate leaks more quickly and act accordingly. Previously, about one third of the water we produced disappeared, which meant that we could not charge for it. Now our objective is 20 percent.”
“We can also minimize the use of chemicals when we know the exact amount that needs to be added to water to achieve the best quality," he added. "This not only saves us money, but is obviously good for the environment too.”
Vikergård says the utility's old control and monitoring system was on its last legs, vulnerable to breakdown and difficult to manage. “After careful analysis, we decided to replace the entire system. Previously, we had different software that communicated in different languages. That’s now replaced with a single software that speaks one common language."
This means MälarEnergi can now track its entire supply process, from the water works via the pumping stations and on to the treatment plant, before the water once again returns to its natural environment.