Should I Turn My Water System Into a Power Plant?

Should I turn my water system into a power plant?

Scott Duren, PE - Brown and Caldwell Peter Brooks – NLine Energy PNWS-AWWA Conference, Boise, Idaho May 4, 2016 The Big Questions

• How will this impact my mission? • What are the benefits? • Where should I do this? • What am I missing?

Brown and Caldwell 2 Core mission goals cannot be compromised

• Product Quality • Customer Satisfaction • Employee and Leadership Development • Operational Optimization • Financial Viability • Infrastructure Stability • Operational Resiliency • Community Sustainability • Water Resource Adequacy • Stakeholder Understanding & Support

Brown and Caldwell 3 Avoid Impacts to Critical Attributes

Brown and Caldwell 4 Provide Benefits to Key Practice Areas

Brown and Caldwell 5 Benefits of Hydroelectric Power

Financing/ • <15 year payback Economics • Positive cash flow in year one

• Climate Change/Sustainability Environmental • Negligible footprint vs. other renewables

• 50-100 year asset life Technology • New models @ 1/3 cost of old hydro

Regulations • FERC Notice of Intent (Exemption)

Brown and Caldwell 6 Potential Sites for In-Conduit Hydro

• High Head, Low Flow • Energy Dissipaters • Pressure Reducing Valves • Minimum Avg Flow >4.5 cfs • Minimum head 100 ft • Low Head, High Flow • Canal Drops • WWTP Outfalls • Minimum Avg Flow > 30 cfs • Minimum head 10 ft

Brown and Caldwell 7 Proper Turbine Selection Optimizes Payback

Pelton Turbine Head Head (ft)

Flow (cfs) Brown and Caldwell 8 Pelton Turbines Suitable for Low Flow/High Head

Brown and Caldwell 9 Multi-Nozzle Pelton Wheels Provide High Efficiency Across a Wide Flow Range

Brown and Caldwell 10 Vertical Pelton Wheel Options

Brown and Caldwell 11 Proper Turbine Selection Optimizes Payback

Turgo Turbine

Francis Turbine

Head Head (ft) Cross-Flow Turbine

Flow (cfs) Brown and Caldwell 12 Turgo-Type Turbines Suitable for Medium Head/Medium Flow

Brown and Caldwell 13 Francis Turbines Suitable for Medium Head/Medium Flow & Pressurized Discharge

Brown and Caldwell 14 Ossberger/Crossflow Turbines Suitable for Medium Head/Medium Flow

Brown and Caldwell 15 Proper Turbine Selection Optimizes Payback

Head Head (ft) Kaplan Turbine

Flow (cfs) Brown and Caldwell 16 Kaplan Turbines Suitable for Low Head/High Flow

Brown and Caldwell 17 Preliminary Analysis Must Be Comprehensive

Feasibility Preliminary Construct & Design Maintain Assessment Analysis Commission

22.5 yrs

Payback Period Payback 4.5 yrs

Time

Brown and Caldwell 18 Distance to Interconnection Point Adds Substantial Capital Costs

Brown and Caldwell 19 Grid Availability Must be Analyzed

3,700 LF of #2 2,600 LF of #2 1.4MW Hydroelectric Aluminum Overhead Aluminum Buried Facility Located at End of Conductor Conductor Power Grid Potential for over $600,000 in additional capital costs to upgrade to existing power lines

Brown and Caldwell 20 Generator Size May Trigger Analysis and Metering Requirements

• Generators >1MW are typically synchronous • PSLF modelling can cost >$250K • Generators > 1MW require Independent System Operator Metering (CA)

Brown and Caldwell 21 Flow Projections Impact Turbine Selection and Power Revenues

Brown and Caldwell 22 Efficiency Throughout Range of Flows Maximizes Return on Investment

NID Loma Rica - Turbine Technology Summary Canyon Hydro Gilkes Gilkes 5-Nozzle Vertical 2-Jet Turgo Francis Pelton Turbine Classification Impulse Impulse Reaction Turbine Technology Pelton Turgo Francis Rated Flow (cfs) 45 54 45 Minimum Flow (cfs) 4.5 10 12 Rated Head (ft) 400 405 353 Capacity Rating (kW) 1,440 1,510 1,040 Water-to-Wire Net Efficiency 85.7% 77.2% 86.9% Annual Generation (kWh) 5,110,000 4,317,000 3,642,000 90%W ofate rFlow-to-Wir eRange Package Cost $1,575,000 $1,269,000 $1,520,000 Process future flows? Yes Yes Yes

Brown and Caldwell 23 Distribution System Control Valves Can Reduce Power Generation Revenues

3700 30 feet of head results in $1.15M of life-cycle cost

3600 Pipe invert 30 CFS - Model 3500 35 CFS - Model 40 CFS - Model 45 CFS - Model 3400 50 CFS - Model 55 CFS - Model

30 CFS - Field ElevationandHGL(ft) 3300 Hydro 35 CFS - Field 40 CFS - Field 45 CFS - Field 50 CFS - Field 3200 Intake Turnout Turnout 55 CFS - Field

3100 0 10000 20000 30000 40000 50000 60000 70000 Distance (ft)

Brown and Caldwell 24 Debris In Existing Pipelines Can Reduce Power Generation Equipment Run-time

Brown and Caldwell 25 One Month of Downtime Costs $30,000 in Lost Revenue Alone

Nozzle Sized for 1- inch Diameter Fully Open

Needle Valves Control Flow Rate at Each Nozzle

Repair Valves Require Long Lead Time

Brown and Caldwell 26 Lining Inspection and Repair Can be Cost Prohibitive

Brown and Caldwell 27 Screening Equipment Adds Capital and Maintenance Costs

Brown and Caldwell 28 Francis Turbine Load Rejection Can Create Transient Surge Event

Ramos, Hydro Review Worldwide, 2010

Brown and Caldwell 29 Surge Tanks Are Expensive and Require Maintenance

Brown and Caldwell 30 Pelton Wheel Nozzle Deflectors Eliminate “Runaway Turbine” Effect

Brown and Caldwell 31 Communications and Controls May Require Upgrades to Maintain Continuous Service • Bypass valves • Additional flow meters • Multiple turbines

Brown and Caldwell 32 Acquiring full control of property may present unforeseen challenges

FAA “No Build Zone” for Future Runway Extension

Proposed Site

Brown and Caldwell 33 Access to Generator and Turbine Runner Can Add Capital Costs

1.44 MW Generator weighs 10 tons!

Brown and Caldwell 34 TIV and Runner Housing Encased in Concrete

Brown and Caldwell 35 Turbine Runner Suspended Above Tailrace

Brown and Caldwell 36 Large Access Required to Remove Runner

Brown and Caldwell 37 Providing Crane Access to Generator Can Add Substantial Costs

Brown and Caldwell 38 Operator Safety Must be Considered

Brown and Caldwell 39 A Thorough Preliminary Design is Necessary

• Knowledge of water system design and operations is key to successfully identifying all life-cycle costs of a project • A thorough preliminary evaluation allows owners to have confidence in determining project feasibility

Brown and Caldwell 40 Questions?

Contact Scott Duren at [email protected] or (503) 820-5574 for additional information

Brown and Caldwell 41