Pump Station Optimization - The Portland Water Bureau’s Approach to Energy Management

Presentation Outline

• Framework • System Overview • Historical Power Use • Pump Station Optimization • Other Strategies

Framework

• Water & Wastewater Utilities Consume 3% of Energy in US

• 90 – 95% of Energy Consumed by Water Utilities is used by pumps –Raw Water Intake –Wells –Treatment Plants –Booster Pump Station

Total Annual Water Bureau Electricity Use for All Facilities

0

5,000,000

10,000,000

15,000,000

20,000,000

25,000,000

30,000,000

35,000,000

40,000,000

2005 2006 2007 2008 2009 2010 2011

Year

kWh

* Baseline is Average Annual Electricty Consumption from 2005 - 08.

Baseline*

2010 Water Bureau Electricty Use by Sector (kWh)

Other 4%

Pump Stations 69%

Treatment 5%

Fountains (pumping) 7%

Occupied Bldg 10%

Groundwater (pumping) 5%

Electricity Consumption

2011 Water Bureau Electricty Use by Sector (kWh)

Groundwater (pumping) 24%

Occupied Bldg 8%

Fountains (pumping) 5%

Treatment 4%

Pump Stations 55%

Other 4%

Monthly Electricity Use for Water Bureau Facilities

0

1000000

2000000

3000000

4000000

5000000

6000000

7000000

8000000

9000000

Jan-

04

Apr

-04

Jul-0

4

Oct

-04

Jan-

05

Apr

-05

Jul-0

5

Oct

-05

Jan-

06

Apr

-06

Jul-0

6

Oct

-06

Jan-

07

Apr

-07

Jul-0

7

Oct

-07

Jan-

08

Apr

-08

Jul-0

8

Oct

-08

Jan-

09

Apr

-09

Jul-0

9

Oct

-09

Jan-

10

Apr

-10

Jul-1

0

Oct

-10

Jan-

11

Apr

-11

Jul-1

1

Oct

-11

Month

Elec

tric

ity (k

Wh)

Total Water Bureau Electricity Use

Ground Water Electricity Use

Pump Stations

Challenges

• Pump and Motor Efficiency

• Weather affects demand for water

Manually Controlled

Valves

Pressure Regulator NW Seblar Terrace

Easement

Overflow 990

Overflow 1044

Penridge Tank

Greenleaf Tanks 1 & 2 Greenleaf PS

(elev. 1224 ft.)

Calvary PS (elev. 992 ft.)

Springville PS (elev. 426 ft.)

Hoyt Park PS (elev. 820 ft.)

Burnside PS (elev. 700 ft.)

Calvary Tank

From Arlington Hts Tanks

From Arlington Hts Tanks

From Whitwood

Tank

To Tualatin Valley WD

Local Distribution Grid

WCC Controlled

Valve

Overflow 1250

Overflow 1200

Overflow 1315

Check Valve

Forest Park High Tank

Willalatin Tank Pressure

Regulator

Water Distribution Schematic for Northwest Hills Facilities Figure 1

Pittock Tank

From Verde Vista P.S.

PWB Strategy • Focus 7 Largest Pump Station • PS Improvements

–Pumping Efficiency Optimization –Pump/Motor Replacement –Weatherization

• Pump Station By-Passing – Is there a way to get water to

customers without pumping?

Pumping Efficiency Optimization

Pump / Motor Replacement Efficiency Range of Pumps at Top 7 Pump Stations

30.0

35.0

40.0

45.0

50.0

55.0

60.0

65.0

70.0

75.0

WashingtonPark to PDXHeights***

Sam Jacksonto PDXHeights

WashingtonPark to

SherwoodField*

Carolina* Fulton* Hoyt** Barbur-Gibbs Sam Jacksonto Marquam

Hill

Sam Jacksonto Broadway

Drive*

Marquam Hill

% E

ffici

ency

Ran

ge

*Currently pumping favors most efficient pump(s)**Pump/Motor replacement project in progress***Efficiency may not be accurate due to flow meter error

Energy savings by favoring more efficient Pump / Pump Station

0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

7,000,000

2006 2007 2008 2009 2010 2011

Elec

trici

ty U

se/Y

ear (

kWh)

Carolina PS

Fulton PS

Hoyt Pump Replacement

• 10% efficiency gain • Project cost =

$41,500 • Electric Utility

Provider incentive covered 50% of project construction cost, through state of Oregon program (ETO).

PS Weatherization

© 2009 Water Research Foundation. ALL RIGHTS RESERVED. 17

• Poor Insulation • Air Leaks • Electric Resistant Heat = up

to 5,000kWh/month • Goal

– Prevent freezing – Reduce humidity – Comfortable work zone?

• Strategies – Reduced temperature (freeze

protection) – Programmable thermostats – Weather-stripping – Louver and vent covers – Winterize/Summerize Checklist

Results

Energy Use by Sector

• Groundwater contributed to increase in 2011

Type of Facility 2005 - 08 Baseline 2010 2011Pump Stations 14,844,882 13,240,241 12,921,575 Groundwater 6,537,153 972,971 5,653,653 Occupied Bldg 2,159,840 2,006,680 1,809,685 Fountains 1,218,799 1,285,600 1,269,767 Treatment 896,601 993,520 856,190 Other 1,147,076 737,320 824,383 Total (kWh) 26,804,350 19,236,332 23,335,253

• 1.8 Million kWh/yr saved • 830 Tons of Carbon Dioxide

Efficiency at top 7 Water Bureau Pump Stations*

0

100

200

300

400

500

600

700

800

2005 2006 2007 2008 2009 2010 2011

Year

gal/k

Wh

** Baseline is Average Efficiency from 2005 - 08.

Baseline**

* Top 7 Water Bureau Pump Stations include Washington Park, Carolina, Fulton, Sam Jackson, Barbur-Gibbs, Hoyt & Calvary

EFFICIENCY

Other Strategies

• Lighting Upgrades • Employee Outreach • Demand Shift

Demand Shift

Sam Jackson Pump Station - 2011 Peak vs. Off-Peak PumpingNote: Electricity use at Sam Jackson Pump Station represents about 6% of total PWB electricity use.

0

100,000

200,000

300,000

400,000

500,000

600,000

700,000

800,000

900,000

1,000,000

Standard Operation* Modified Operation**

kWh

Peak Pumping (Mon - Sat 6:00 am - 10:00 pm)

Off-Peak Pumping (Mon - Sat 10:00 pm - 6:00 amand All Day Sunday)

This operational change represents $5000 worth of savings during 2011.

*Standard Operation was prior to Jan 2011, when pumps were operated approximately 2/3 of the time during peak period and 1/3 of the time during off-peak period.

**Modified Operation is after Jan 2011 when pumps were operated as much as possible during the off-peak period. Pumps may be operated during the peak period if tank levels are low or for other necessary operational purposes.

Renewable Energy

Meter Shop Solar

Solar on the Slough

Vernon-Micro Hydro Generator Groundwater Treatment Bldg Solar

Questions?