Energy Use Efficiency Portland Water District Case Study

Joel Anderson, Chief Operator Sebago Lake Water Treatment Facility

T&D Time of Use Schedules

Transmission & Distribution Time of Use Billing

Electrical Energy Costs

• Constellation Energy – Now based on TOU

• Peak (Weekdays, 7 AM-11 PM): $0.0565/kWh • Off Peak (Weekdays, 11 PM to 7 AM); weekends and

holidays: $0.0419/kWh – 26% power increase during Peak Periods – Forward Capacity Charges (Fixed or “Pass Through”):

Pass through charges based on your facility’s demand during the ISO-NE peak hourly demand

– Using Maine Power Options as a resource – Cost apply to every kWh consumed, not just 15

minute peak demand!

Constellation Energy Bill

Maximizing TOU Operation

Off Peak: $0.0419/kW

Peak: $0.0565/kW

No Demand

Rapid Storage Turnover 25% Cost Savings

Gorham Tank, August 8, 2010

Standish Distribution System

SolarBee

Standish Tank, August 8, 2010

Pax Mixing Unit

Upgrade of Primary Treatment • Replaced 20-year old

inefficient ozone generator • $300,000 grant received

from Efficiency Maine Trust Competitive Program

• UV Reactors programmed to minimize lamp life and power consumption

SLWTF Power Consumption Month kWh Million Gals kWh/MG

Jun-13 389,700 705.289 552.5

Jul-13 342,000 746.576 458.1

Aug-13 396,900 803.842 493.8

Total 1,128,600 2255.707 500.3

Month kWh Million Gals kWh/MG

Jun-14 271,800 766.269 354.7

Jul-14 358,200 824.019 434.7

Aug-14 233,100 764.543 304.9

Total 863,100 2354.831 366.5

kWh kWh/MG

Difference 265,500 133.8 26.7%

Pumping Water • Typically consumes 40% of a facility’s power • One RW Pump vs Two at 18 MGD: 130 kW vs 166 kW • Potential Savings: $19,000 Annually

L:ighting Efficiency Project

• Replace: low efficiency Metal Halide; 1-lamp HO strips,; compact fluorescent; 2 & 4 lamp T12 (magnetic ballasts); High Pressure Sodium

• Install: HIF Fluorescent Lowboy (high ballast factor);2 & 4 lamp F32T8, FO17, & FO25; LEDs

• Total project cost: $33,000 • Efficiency Maine Grant: $8,200 • PWD Cost: $25,800 • Project payback: 3 years • Annual savings: $7,000

Miscellaneous Items • Participation in Demand Response Programs • Heating unused buildings • Chemical costs savings

– Re-evaluating chemicals & chemical dosages – Southern Maine Water Council

• Involve operational staff by showing them the real power costs numbers

• Become of member of Maine Power Options • Set priorities: Meet customer demand, Comply

w/regulations, address water quality, THEN conserve energy cost!