Water Energy Nexus. Alexander R. Coate October 24, 2012

Transcription

1 Water Energy Nexus Alexander R. Coate October 24, 2012

2 Overview Background EBMUD and State Energy Use Energy Use and Water Supply Energy Management Strategy Summary

3 EBMUD Service Area

4 EBMUD Background EBMUD annual energy expense ~$11 million* 90% of water supply from Mokelumne River Watershed Pre-Drought Approximately 220 MGD average water production Post-Drought Approximately 180 MGD average water production *Potable water treatment and distribution only

5 EBMUD s Mokelumne Source Water Supply System No Title Example Slide Use Sparingly

6 District Energy Use & Costs Water System - Fiscal Year 2012* Energy Use MWh Cost (million $) Distribution Pumping 50,000 $ 6.7 Water Treatment 21,000 $ 2.7 Raw Water Pumping 3,000 $ 0.3 Admin & Maint. 7,000 $ 1.1 TOTALS 81,000 $10.8 * Preliminary

7 Water Supply in California 70% of state s total stream runoff north of Sacramento 80% of water demand is south of Sacramento

8 Typical Water System Energy Use in Northern & Southern California Energy Use (kwh/mg) EBMUD N. CA S. CA kwh/mg: Kilowatt-hours per million gallons EBMUD energy use for calendar year 2006 Northern and Southern California Energy Use from November 2005 CEC Final Staff Report, California s Water-Energy Relationship

9 Major Energy Components ENERGY USE - kwh/mg (percent of total) Component EBMUD Typical Typical Distribution 917 (73%) Treatment 156 No. CA Utility 1200 (83%) 100 So. CA Utility 1200 (12%) 100 Supply/ Conveyance (14%) 177 (13%) (7%) 150 (10%) (1%) 8900 (87%) TOTAL kwh/mg: Kilowatt-hours per million gallons EBMUD energy use for calendar year 2006 Northern and Southern California Energy Use from November 2005 CEC Final Staff Report, California s Water-Energy Relationship

10 EBMUD Energy Use Normal Year Supply/Conveyance Treatment Distribution TOTAL 177 kwh/mg 156 kwh/mg 917 kwh/mg 1250 kwh/mg Gravity Water Customers = ~ 400 kwh / MG Pumped Water Customers ~ 2000 kwh/ MG

11 EBMUD Dry Year Energy Use Supply/Conveyance Treatment Distribution TOTAL 1423 kwh/mg 1610 kwh/mg 917 kwh/mg 3950 kwh/mg EBMUD Dry Year Scenario: Includes Mokelumne supply, supplemental water supply, desalination, groundwater and recycled water

12 Energy Management Strategy Water Conservation Energy Management Strategy Goals Diversify Energy Supplies Minimize Energy Use and Costs Education and Information Sharing Ensure energy projects are prioritized based on best overall cost savings

13 Water Conservation Water conservation reduces energy use EBMUD water conservation On-site water surveys Waterwise self-survey kits Rebates for high-efficiency toilets and appliances Lawn conservation rebates Irrigation system rebates Customer education and information

14 Diversify Energy Supplies Project Description Revenue Savings Hydropower 40 MW Total Pardee and Camanche Power plants PV Generation (Solar) 430 Sobrante WTP 30 Adeline Maintenance Center Power Purchase Agreements 5 District Sites 775 kw Total Capacity $4.5 Million in FY12 $850,000 saving over 25-year 10% offset of utility purchases $900,000 savings over 20-year contract

15 Hydropower Two Hydropower Plants Pardee 30 MW Camanche 10 MW Average Annual Generation 185,000 MWh Average Annual Energy Use 100,000 MWh Net energy producer

16 Wastewater Cogeneration Renewable energy production doubled from 2.5 MW to 5.5 MW Power plant capacity expansion to 11 MW completed in 2012 Net electricity producer and sells excess power

17 PV Power Purchase Agreements Purchase electricity from a third party owned & operated PV system on District property No capital investment or maintenance costs Investors keep tax credits, rebates, GHG and REC Performance based: pay for power produced

18 Primary 2040 Portfolio Evaluation Included Greenhouse Gas Emissions

19 Energy Comparison of EBMUD s Supply Options Current Water Supply Options Normal Years (1) 325 Drought Years -Freeport 1,555 Drought Years Bayside Groundwater Banking Project (2) 1,550 Future Water Supply Options (4) Regional Desalination Project (3) 2,700 Water Transfers 1,700 San Joaquin Groundwater Banking/Exchange 2,650 Sacramento Basin Groundwater Banking/Exchange 2,650 Enlarge Lower Bear Reservoir 1, ,000 1,500 2,000 2,500 3,000 Energy Consumption (KWh/AF) Notes: 1. Pardee (Mokelumne) operate most of the time under gravity and require very low conveyance or treatment energy. 2. Energy estimates from WSMP 2040 Table Energy use for Bayside Phase 1 is assumed to be similar to Phase Regional Desalination includes pumping into Mokelumne aqueducts (838) and additional 315 kwh/af re-treatment (100) and distribution (215). 4. Energy estimates from WSMP 2040 Table 6-20.

20 Minimize Energy Use Project Description Savings/Year Natural Gas Microturbines 600 admin building $125,000 WTP Lighting Upgrades High efficiency lighting replacement at Lafayette, Orinda and Sobrante WTP $44,000 Hybrid Fleet Toyota hybrid fleet $35,000

21 Minimize Energy Costs Project Description Savings/Year San Ramon Valley Energy Management Optimization shift energy use from peak to part peak and off peak $370,000 Demand Response PG&E s Peak Demand Pricing Program $100,000 Natural Gas Contract Gas purchases from California s Dept of General services for microturbines $65,000 Raw Water System Optimization Maximize gravity flow on Moklumne Aqueducts and optimize operation of raw water pumping $500,000

22 Summary EBMUD is a net energy producer (44,000 MWh excess in FY12) Conveyance and distribution requires significant energy Location and quality of source greatly affects energy use Energy will be a significant factor in the future Climate change may alter existing supplies & energy use Cost of energy from fossil fuel difficult to control Water conservation and renewable energy projects reduce greenhouse gas emissions & stabilize energy use