Support AB32 GHG Reductions and Save Cost As Well? Wayne Spittal AWWA CA/NV Section Spring 2008,...
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Transcript of Support AB32 GHG Reductions and Save Cost As Well? Wayne Spittal AWWA CA/NV Section Spring 2008,...
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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0 1 2 3 4 5 6 7 8 9 10
Eff
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(ft)
Flow (MGD)
Variable Speed Drive Performance
100% Speed
BEP - Best Efficiency Point Curve
Initial Head Prediction
85% Speed
80% Speed - BEP
70% Speed
50
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0 1 2 3 4 5 6 7 8 9 10
Eff
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nc
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He
ad
(ft)
Flow (MGD)
Variable Speed Drive Performance
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)