Support AB32 GHG Reductions and Save Cost As Well?

Wayne SpittalAWWA CA/NV Section

Spring 2008, Hollywood CA

The Issue

• Global warming has now been firmly bought to the attention of the general public Internationally

• Water Utilities are particularly exposed, they are high energy users; raw water supplies are affected while simultaneously is customer water demand

• “The more than 60,000 water systems and 15,000 wastewater systems in the United States are among the country’s largest energy consumers, using about 75 billion kWh/yr nationally —That’s 3 percent of annual U.S. electricity consumption."

Electric Power Research Institute, Energy Audit Manual for Water/Wastewater Facilities, (Palo Alto: 1999), Executive Summary

California Energy Overview

• Population : 34 million• 2004 Total Electricity Use:

◦ 271,000 GWh– 19% Used for Water– or 51 million MWh

• 2004 Peak Demand:◦ 56,400 MW

• Annual growth:◦ MWh Consumption – 1.4%

◦ MW Peak – 1.65%

Ref: CEC Martha Krebs PhD, Feb 2007

Total Electricity Use Per Capita

• Californians use almost 50% less electricity than the US average

Global Warming Solutions Act of 2006 (AB 32)

• Establishes first-in-the-world regulatory and market based program to achieve real, quantifiable, cost effective GHG reductions

• Creates a state wide GHG emission limit to reduce emissions to 1990 levels by 2020 (i.e., the target specified in Executive Order S-3-05)

• Designates Air Resources Board as state agency charged with monitoring and regulating sources of GHG emissions

Source: “California Climate Policy Landscape,” Shankar B. Prasad, Deputy Secretary for Science & Environmental Justice, California Environmental Protection Agency, September 2006.

California Climate Change Targets

• By 2020, California will need to remove ~ 180 million tons of CO2 per year

Typical Power Use in Water Distribution

Up to 95% of energy consumption is used for pumping

Pump Life-Cycle Costs Electric motors driving pumps are not necessarily efficient

Purchasing decision lead by lowest up from cost, not efficiency

Utility Energy Costs Management

• Standard energy audits generally look for low hanging fruit over the short term including:◦ Elimination of obvious system inefficiencies

◦ Negotiation of better electric tariff rates

• Over the mid to longer term, modelling techniques are then employed to:◦ Improved standard operating procedures (SOPs)

◦ Equipment upgrade programs (CIP / master plans)

• In parallel, progressive utilities are also looking at adaptive optimization to:◦ Maximize performance of assets mix currently available

◦ Automate complex decision making processes required to ensure optimum efficiency and water turnover

Optimizing Water Distribution Pumping

• Pump scheduling systems so-far have focused mainly on time-of-use kWh and peak kW charge avoidance

• However, targeting efficiency for each pump and pump station can also lead to considerable kWh reductions

• Each kWh saved also leads indirectly to CO2 and other greenhouse gas (GHG) reductions

• Reducing the kWh/MG/ft should therefore be a goal for every water utility in respect of emissions management

• Unfortunately static testing of pumps and individual pump upgrades is not enough on its own

• The dynamics of a moving system curve means real-time pump selection is required

Real-Time Pump Performance

Figure Telemetry Data overlaid on pump curve

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Variable Speed Drive Performance

100% Speed

BEP - Best Efficiency Point Curve

Initial Head Prediction

85% Speed

80% Speed - BEP

70% Speed

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100% Speed

BEP - Best Efficiency Point Curve

Initial Head Prediction

85% Speed

80% Speed - BEP

70% Speed

Variable Speed Pump Performance

A New Cost Minimization Tool

• Over the last 4 years, Derceto has implemented energy cost optimization systems with leading US water utilities

• Five key cost reduction techniques were employed◦ Electrical load shifting in time, to maximize utilisation of low

cost kWh tariff blocks (time-of-use tariffs)

◦ Peak electricity kW demand reduction

◦ Energy efficiency improvements from pumps and pumping plants.

◦ Utilization of lowest production and chemical cost sources of water.

◦ Utilization of shortest path between source and destination

Operator Panel201

Solver / EPAnet208

Operations Simulator209

PC onLAN

Application Manager218

PC on LAN

Key Energy Management Modules

Primary Database

Backup Database

Aquadapt Primary Database

(Live Server)

AquadaptBack-up Database (Historical Server)

Dashboard210

PC onLAN

Data Cleaner206

SCADA Interface203

OPC

Current day / real-time

Water Utility SCADA System

A New Energy Minimization Tool

• Of the 5 techniques employed, energy efficiency improvements produced the most unexpected outcome

• The optimizer software used searches for the lowest cost schedules that deliver the required mass balance of water within specified system constraints

• Part of the half-hourly adaption routine is to dynamically calculate energy use and cost for each feasible schedule

• Part of this calculation is to hydraulic model and compare the feasible schedules. This means overall pump wire-to-water efficiency becomes an important factor.

• Selected field results ..

The Aquadapt optimizer has achieved significant efficiency gains

This affect was seen system wide

Before and After Pump Performance

Client Electricity Supplier Source of Emissions Information

Year of emissions estimate

EBMUD Pacific Gas & Electric Company California Climate Action Registry

2005

EMWD Southern California Edison California Climate Action Registry

2005

WaterOne Board of Public Utilities (BPU) US Environmental Protection Agency’s Acid Rain Program

2005

Kansas City Power & Light Co (KCPL)

KCPL 2006 Environment Report

2006

WSSC PJM Interconnection PJM Environmental Information Services

2006

Client Electricity Supplier Source of Emissions Information

Year of emissions estimate

EBMUD Pacific Gas & Electric Company California Climate Action Registry

2005

EMWD Southern California Edison California Climate Action Registry

2005

WaterOne Board of Public Utilities (BPU) US Environmental Protection Agency’s Acid Rain Program

2005

Kansas City Power & Light Co (KCPL)

KCPL 2006 Environment Report

2006

WSSC PJM Interconnection PJM Environmental Information Services

2006

Calculating CO2 Emission Reductions

• There are many web sites with data freely available on CO2 emissions per kWh (or MWh) used in an area.

• Once the CO2 pounds (or metric tons) is determined, this is multiplied by the energy saved (MWh)

Water Utility Case Studies

   Utility System under Optimization

Storage tanks

Pressure zones

Pump stations

PumpsAuto Valves

Total Utility Population

East Bay MUD, CA – Stage 1 28 26 20 66 4 1.3M

Washington Suburban SC, MD 57 15 18 81 25 1.7M

WaterOne, KS 25 3 26 84 11 0.4M

Eastern Municipal WD, CA – Stage 1 26 13 26 62 2 0.6M

Eastern Municipal WD, CA – Stage 2 68 44 58 143 9 0.6M

Installed in some of the largest US cities, some operating since 2004

Utility Case Studies – GHG Reduction

Greenhouse gas reductions through efficiency improvements

Water UtilitySystem

Average MWh per Year

Average Efficiency Gain under Derceto

Optimizer

EPA eGRID 2004CO2 Emissions

(Tons/MWh)

Extrapolated CO2 Reduction

per Year (Metric Tons)

AnnualEnergy Cost

Savings

EBMUD 26,000 6.1% 0. 502 800 13%

EMWD Stage 1 7,000 8.4% 0. 515300

(excl. gas)10% Stg 115% Stg 2

WSSC 99,000 8.3% 0. 547 4,500 11%

WaterOne 94,000 6.0% 0. 845 4,800 20%

Conclusions

• At 3% the US water industry uses approximately $10B of electricity per year to pump water consuming 100 million MWh of electricity (EIA 2006).

• A reduction of 6% to 9% in this energy consumption through efficiency improvements would therefore lead to saving of 6 to 9 MWh per year.

• EPA national average CO2 emission is 0.6 metric tons per MWh and for California approx 0.4.

• The potential annual CO2 reduction through adaptive optimizations is therefore up to 5 million metric tons nationally and up to 2 million metric tons in California

• This is a significant step forward in achieving CARB’s objectives for its AB32 responsibilities with water utilities

• And adaptive optimization is cost effective (2-4 year payback)