Water Treatment Plants Can Achieve Energy Neutrality

saving water
Automation World, March 24, 2016. Image credit: Quadronet_Webdesign

Typically, water and wastewater treatment processes account for 25-40 percent of a local municipality’s electricity consumption. With energy reduction in water production, water distribution, wastewater pumping and wastewater treatment, combined with increased energy production from the wastewater treatment process, water service companies can achieve energy neutrality.

By introducing AC drives into water production, for example, water service companies have been able to achieve 20-45 percent energy reduction, Warming said. With optimized pressure management, water distribution has seen 20-40 percent energy reduction, as well as 20-40 percent leakage reduction.

.@DanfossDrives is enabling water plants to produce a net surplus of energy & reduce their CO2 footprint. Click To Tweet

Leakage management can be important, with water service organizations typically facing significant water losses from leaking pipes, Warming said. In one case in Asia, he saw leakage as high as 85 percent. “So 85 percent of the water was not reaching customers because of a leak,” he added.

Installation of more pumps and drives in 112 systems in 10 different countries demonstrated a typical leakage reduction of 38 percent. Other benefits included energy consumption reduced by 20-40 percent, extended pipe lifetime of 10-20 years, and fewer network-related complaints.

In wastewater pumping, a key to achieving 5-25 percent energy reduction has been keeping pumps clean. To combat pumps clogging over time, causing efficiency to drop, Danfoss has incorporated a de-ragging function into its drive. When necessary, the drive can turn the pump’s propeller the opposite way to let the pump clean itself, Warming explained.

The drive is the key element in improving efficiencies in wastewater treatment also, regulating low-load and high-load activities to reduce energy use by 25-60 percent.

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