Sustainable Energy Management

Transcription

1 Sustainable Energy Management Achieving Energy Independence at Wastewater Utilities Dru Whitlock, PE 1

2 Global Renewable Energy Drivers Climate Change (Global Environmental Issues) Global Economic Downturn Oil Reserve Uncertainty Population Global Increase in Standard of Living Security Aggressive Governmental Policy Change Sustainable Systems/Renewable Energy 2

3 June 2007: Goldman s 5 Renewable Energy Drivers 1. Enacting renewable portfolio standards 2. Boost enforcement of RPS 3. Enact a carbon cap-and-trade system or a carbon tax 4. A significant increase in fossil fuel prices 5. Political will 3

4 Annual Energy Outlook 2008 Price Forecasts 125 World Oil Price nominal dollars per barrel Natural Gas Wellhead Price nominal dollars per thousand cubic feet Coal Minemouth Price nominal dollars per ton Average Electricity Price nominal cents per kilowatthour

5 GHG Regulations and Initiatives Federal USEPA s Draft Proposed Mandatory Greenhouse Gas Reporting Rule American Clean Energy and Security Act of 2009 Regional Climate Initiatives State Climate Initiatives Local Climate Initiatives 5

6 Strategies for Decreasing Non-Renewable Energy Demand at WWTP Conservation Load Control Process Utilization Efficiency Process Optimization I&C HVAC VFD Equipment 45% 40% 35% 30% 25% 20% 15% 10% 5% 0% Influent pumping Headworks Primary sedimentation Aeration Secondary sedimentation Return activated sludge pumping UV disinfection Thickening Anaerobic digestion Dewatering Lighting HVAC Odor control 6

7 Increasing Renewable Energy Supply at WWTP Energy Supply Integrated Biogas Heat Pumps Hydro Biosolids to Energy Supplemental Solar Wind Emerging Algae Microbial Fuel Cells Biosolids to Energy Small Hydro 7

8 Hot Water or Steam Relief to Atmosphere Waste Gas Flare High Performance Anaerobic Digesters Biosolids Storage Compression Biogas NG Pipeline Gas Treatment Boilers Direct Drive Engine Hot Water or Steam Cogeneration* Fuel Cell Rotating Equipment Electricity *ICE, Turbine, or Microturbine Electricity Hot Water

9 CHP Summary Engine Generator Turbine Generator Micro Turbine Fuel Cell Unit Size, kw 150 to 1500 Over Appropriate Plant Size Small to Large Large Small Large Efficiency, % to Thermal Efficiency, % Overall Efficiency, % to Typical Costs Maintenance, $/kwh Installed, $/kw Source: LCAMER WERF 9

10 How can we make more biogas? The feedstock FOG wastes (~100% volatile solids) Food wastes (diverse characteristics) Advanced Anaerobic Digestion AD Pre-conditioning 10

11 Optimizing Sludge Processing Headworks Primary Treatment Secondary Treatment Plant Influent Plant Effluent Solids Handling PS to Digestion Activated Sludge WAS to Digestion Dewatering/ Disposal Extended Aeration Cannibal Ozone Homogenization Sonication Thermal Hydrolysis Focused Pulse Power Thermophilic Digestion Phased Digestion Acid/Enzymatic Hydrolysis 11

12 Solar Technologies 12

13 Solar Power Flat plate collector (PV) Concentrated Solar Power (CSP) Grid vs. off-grid Source: 13

14 Implementing Solar Advantages Concurrence with Peak Demand Low Operating Costs Low Environmental Footprint Scalability yr Panel Life Easy to Site & Permit Minimal Transmission Loss No cooling water Disadvantages High Capital Costs Intermittent Incentive & Policy Dependence 14

15 Land Requirements for PV 100kW requires ~ 15,000 square feet 1 MW requires 4-10 acres, depending on mounting options 15

16 Simple Payback Analysis Total PV System Size 100 kw Cost ~ $750,000 35% tax credit (State) $262,500 30% tax credit (Fed) $225,000 Depreciation (NPV) $190,896 Balance Cost $71,604 Annual kwh from PV system 130,876 Average Real Time Price of Electricity $0.073 / kwh Annual Savings from PV kwh $9,554 Payback Period 7.5 years 16

17 Wind Power 1 MW 100 kw 1.8 kw 17

18 Wind Power Economics Small Medium Large Capital Cost ($/kw) $4,000 to $8,000 $3,000 to $6,000 $2,000 to $2,500 Power at Site Avg. Speeds 1 kw Turbine 100 kw Turbine 2.3 MW Turbine American Recovery & Reinvestment Act provides 30% grant from U.S. Treasury for qualifying wind projects under construction during 2009 and

19 Future Outlook Renewable Energy Cost Reductions Incentives from the American Recovery and Reinvestment Act of 2009 Goldman s economic drivers for renewable energy are evolving quickly 1. Enacting renewable portfolio standards 2. Boost enforcement of RPS 3. Enact a carbon cap-and-trade system or a carbon tax 4. A significant increase in fossil fuel prices 5. Political will 19

20 Sustainable Energy Management Achieving Energy Independence at Wastewater Utilities Dru Whitlock, PE

21 U.S. electricity demand growth slowing (3-year moving average) 12% History Annual Growth Projections 10% 8% 6% 1950s 1960s 1970s 1980s 1990s % 7.3% 4.2% 3.1% 2.4% 1.2% 1.1% 4% 2% 0%

22 CO2 Emissions 3,500 million metric tons 3,000 2,500 2,000 7, ,50 0 6, ,50 0 Total Carbon Dioxide Emissions A EO Other Electricity Coal Natural Gas Petroleum 2006 AEO , ,500 1, Residential Commercial Industrial Transportation Electric Power Delivered, including losses 22