REGION OF DURHAM
Shifting load to save money

Moving and treating water and wastewater is a high-energy process. In Durham, roughly 70 per cent of the Region’s electricity bill is dedicated to treating and pumping water and wastewater – making it an obvious target for energy saving and load-shifting.

Durham’s solution? Go high-tech.

“Pumping is where the highest electricity use takes place,” said Christine Dejan, Energy Efficiency Project Engineer for Durham Region Works Department. “We have adopted highly-sophisticated software that optimizes our pumping schedule. Right now, we anticipate savings of 10 per cent a year when municipalities move to hourly prices in 2008.”

Through its largest lakefront water distribution system, the Region meets the water requirements of its 576,000 citizens with three major water supply plants, 10 reservoirs and elevated tanks and 12 major pumping stations. These are all controlled through a single operational centre in the Ajax Water Supply Plant – which acts as the hub of the Works Department’s Energy Optimization Project.

This project comprises four components:

• Demand Forecasting – taking historical population and weather data to predict the hourly water needs over the next 24 hours.

• Hydraulic Modeling – mimicking water production and distribution systems to determine the most efficient way to meet the water pressure and flow demand forecast. For example, the system can decide how much water to pump into reservoirs overnight to take advantage of lower electricity prices.

• Pump Scheduling – determining the most cost-effective pumping schedule in the three water supply plants by continually tracking reservoir levels, flow capacity and energy consumption monitoring systems.

• Power Monitoring – tracking and validating real-time energy use and historical patterns set by the forecasting and modelling systems, as well as analysing interval meters, peak consumption and electricity load profiles, monitoring price trends and power quality reports.

By extracting every last detail about their energy needs and then using this information to project future needs, the Region is able to closely manage how much energy it uses and focus that energy use during lower-priced times of the day.

The result is a system that rivals the world’s leading water management systems in the use of technology. The electricity savings, through energy efficiency and load shifting, will keep operating costs down and water rates low.

The Region is also able to benefit from its load-shifting capabilities by providing demand response through the IESO’s Emergency Load Reduction Program, which provides payments for reducing demand when the electricity system is under stress. According to Dejan, the project’s success depends on the commitment of plant operators.

“We work closely with operations staff – the people who are the decision makers and actually run the water and wastewater facilities. Their buy-in is important,” said Dejan. “In the water sector, their priorities are to meet drinking water regulations and ensure adequate supply. Up until recently, electricity use hasn’t been an issue. Now that we’ve been working together, electricity management is also becoming a priority.”

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