A misunderstood concept about power quality is that its sole effects are on power utilities, whereas it can influence any industry that uses electrical motors and devices, i.e. almost all industries.
The water sector is not an exception.
According to the EPA, approximately 30%-40% of the cost of water and wastewater treatment processes comes from electricity. On the other hand, according to the Electric Power Research Institute (EPRI) report in 2002, about 4% of the nation’s electricity consumption comes from the water sector (treatment and distribution).
These data indicate that, as customers, about 40% of our municipality’s bill goes to the electricity usage in water/wastewater plants, while 4% of our electricity bill goes toward the water! Hence, the amount of energy consumption for treating and moving water and wastewater directly affects our water, sewage, and electricity bills.
The electrical power is spent on pumping, carrying, treating, and distributing water as well as for collecting, treating, and discharging wastewater, all of which performed by pumps or other equipment including at least one motor drive. This is why the water sector, along with other industries, is directly affected by power quality. It is well established that power quality plays a critical role in the lifespan and operating efficiency of pumps and motor drives, i.e. the cost of electricity.
Considering the great effect of electricity consumption on customers (via their utility bills), water/wastewater treatment owners (mostly governmental entities), and planet earth (climate change effects), testing for the power quality of equipment in water and wastewater treatment plants seem to be vital, and long overdue. Identifying power quality issues in these devices, however, is not easy because their symptoms and intensity vary widely.
Nevertheless, a proper power quality monitoring system can easily recognize and help with resolving the issues.
Article contributed by:
Farrah Moazeni, PhD
Faculty of Environmental Engineering, Penn State Harrisburg