Biogas Cogeneration of Heat & PowerEnergy Reduction at the McAlpine Creek Wastewater Management Facility

Biogas Cogeneration of Heat & PowerEnergy Reduction at the McAlpine Creek Wastewater Management Facility www.tinyurl.com/combinedheatandpower Jon Lapsley, PE CDM Smith Will Rice CLT Water November 14, 2016 Raleigh, NC

Outline Charlotte Water and McAlpine Creek WWMF Background Implementation History Biogas Study Findings and Recommendations Summary of Improvements Current Status and Lessons Learned Questions

Charlotte Water and McAlpine Creek WWMF

Background Charlotte and Mecklenburg County Over 775,000 Customers 5 Treatment Facilities

McAlpine Creek WWMF Largest Facility at 64 mgd Receives Primary Sludge and WAS from Sugar Creek WWTP Also has capability to receive flow from Sugar/ Irwin

Energy In Wastewater WERF- ENER1C12 A GUIDE TO NET-ZERO ENERGY SOLUTIONS FOR WATER RESOURCE RECOVERY FACILITIES)

McAlpine Creek WWMF You ever thought of taking that methane and making power? The General Public 2+ flares, 24/7/365

Implementation History

Implementation History North Carolina Solar Center Biogas Study CDM Smith Biogas Utilization report The Intern Started The Intern Study (i.e. lots of phone calls to ORCs/ Chiefs) (Fall) Attempted DBOF/ESCO: Limited Interest Considered Alternatives and Cost Paybacks (Winter) RFP CLT Water Purchased Cogeneration Engine (Summer) NCDEQ CWSRF Loan Funding Approved Final Design and Bidding Construction Begins

2009/2010 Biogas Study and Findings

CLT Water Commissioned Several Studies North Carolina Solar Center Evaluated Multiple Methods Internal Combustion Engine most efficient and least life cycle cost 9-14 year Payback

CLT Water Commissioned Several Studies Biogas Utilization Study Updated Anaerobic Digester Gas Projections Future Co-digestion considerations Preliminary Siting and Layouts

Anaerobic Digester Gas Projections >2 MW

Anaerobic Digester Gas Analysis (2010-2014) Average Carbon Dioxide: 32.1% Average Methane: 64.3% Average Nitrogen: 1.2% Average Oxygen: 0.3% Average Total Siloxanes: 0.606 ppmv Average Hydrogen Sulfide: 8.5 ppmv Average HHV: 637 BTU/cubic foot Average LHV: 573 BTU/cubic foot (GOOD) (VERY LOW)

2011-2013 The Intern and the ESCOs

The Intern(al) Study on CHP and RFP Lots of Phone Calls How well and how often do your engines run? How did you procure yours? Who does your maintenance? Who built it? What were your lessons learned? Conclusion: CLTW didn t want financial or operational risk Attempted to do Design/ Build/ Operate/ Finance/Own Failed: ESCOs didn t want to Own/ Finance

2013/2014 The Planets Align: State Revolving Fund and A Cancelled Order

Winter 2013 RFP CLT Water Purchased Cogeneration Engine Order for 4x GE Jenbacher J320 Containerized Engines Cancelled Nixon Energy contacted CLTW RFP was released for 1 MW CHP Engines GE was lowest responsive bidder, engine was purchased at significant discount

Engine Arrival 64,000 lbs Telescoping Trailer Multiple Ports 2 trucks

2014 CWSRF Funding First Application was not accepted Second Time Application was accepted Borrowing $3.2 million at 0% Green Project Reducing Power Use by 20% OR Generating Power

Summary of Improvements

Main Project Components Anaerobic Digester Gas Piping System Gas Conditioning System Cogeneration Engine Hot water system Electrical improvements with Duke Energy

Anaerobic Digester Gas Piping Getting from A to B Above ground vs. buried piping Connection downstream of existing H2S Scrubbers

Gas Conditioning System Downstream of existing Hydrogen Sulfide scrubbers Packaged Treatment System Gas compression and drying Siloxane scrubbing system/activated carbon filters

Cogeneration Engine CLT Water Purchased Cogeneration Engine Jenbacher 1,059 kw/hr, 2,430 MBTU/hr Engine Table Cooler Engine Exhaust Decoupling Heat Exchanger Engine Container Exhaust Gas Recovery Electrical Transformer

Hot Water System Balance heating needs vs. biogas use (now 3 biogas avenues) Biogas fired boiler system for digester hot water heating Combined Heat and Power Engine Flare System Connect at existing HW to HW Heat Exchanger

Hot Water System Heat Recovery from engine block/jacket and exhaust gas Closed loop system with recirculation pump Balancing valves and recirculation pumps on VFDs

Electrical Improvements Driven by Power Purchase Agreement (PPA) 1 MW Restriction by Duke Energy Sell All PPA Major Components 480 V to 24 kv step up transformer Underground system to existing 24 kv system New poles and metering by Duke Energy

Current Status and Lessons Learned

Current Status Construction is underway Startup Scheduled for Early 2017

Construction Photographs

Combating fears: Enough gas, cost prohibitive, does not impact permit compliance Engine acquisition: In the bid vs. pre-purchase Power cost vs. payback: delivery method Gas conditioning: Upfront capital vs. O&M costs Site visits critical: Operations and Management Funding sources: Energy reduction is big Power Purchase Agreements: Negotiating varies Operations: Consider 3 rd party O&M Contracts Container 3 rd Party Listing US vs. International Standards

www.tinyurl.com/combinedheatandpower www.tinyurl.com/combinedheatandpower Questions? Will Rice: wrice@charlottenc.gov Jon Lapsley: lapsleyjs@cdmsmith.com www.tinyurl.com/combinedheatandpower