Army Landfill Gas to Electricity Feasibility Study

Mary Matthews Hains, PEAMEC Environment and

Infrastructure

Learning Objectives

• Understand the criteria that can be applied to identify strong landfill candidates for production of methane gas for electricity

• Understand the technical and economic factors that prove the feasibility of landfill gas to electricity projects

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Purpose of Study

• Identify renewable energy potential from landfill gases at all Army installations in CONUS• 121 sites considered

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Process

• Develop evaluation criteria; score database

• Identify strongest candidates through questionnaires, modeling, and on-site records review with stakeholders

• Identify equipment specs and preliminary cost to calculate potential feasibility

• Conduct charrette of feasible options; prepare programming documents

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Evaluation Criteria

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Waste Compo-sition

Local Electric Rates

Size (Waste in

Place)Landfill

Age

Gas Collection

SystemNet Zero

Installation

Excellent

MSW reported

>10 ¢/kWh

>1.5M Tons

Active or Closed <5 yrs. ago Yes Yes

Good/ Marginal NA

>7.5 ¢/kWh

>0.75M Tons

Closed >5 and <10 yrs. ago NA NA

Poor NA<7.5

¢/kWh<0.75

M Tons

Closed >10 yrs.

ago NA NA

Most important Least important

Initial Screening

• Southern DoD Landfill Database– Desktop analysis; uses broad assumptions

• Unknown waste composition? Assume some MSW

– Supplemented with other databases• DoD Solid Waste Annual Reporting

– Shows remaining waste volume, projected closure date, and gas collection system type

• EPA’s Landfill Methane Outreach Program – Defines candidates as active or closed <5 years, with >1M

tons of waste, and no planned/operational LFG project

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• O&M + Replacement Costs Lifetime Savings Project SIR

• Fort Belvoir 0 $ 1,050,000 $ 1,021,733 $ 2,207,520 1.07

• Fort Lewis-McChord 2 $ 1,900,000 $1,509,267 $ 2,365,200 0.69

• Fort Meade 0 $ 1,050,000 $ 551,880 $ 3,090,528 1.93

• Fort Riley 1 1,050,000 315,360 883,008 0.65

• Fort Hood 0 $ 1,900,000 $10,479,960 $ 23,935,824 1.93

• Fort Roberts Preliminary modeling indicates insufficient gas quantities.

• Fort Pickett 1 1,050,000 $ 197,100 $788,400 0.63

• Fort Irwin 0 $ 11,250,000 $ 6 3,087,293 $ 145,349,424 1.96

• Sierra Army Depot Preliminary modeling indicates insufficient gas quantities.

• Fort Bliss Preliminary modeling indicates insufficient gas quantities.

• Yuma Proving Ground 2 $ 1,900,000 $ 4 ,539,980 $ 6,527,952 1.01

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Results of Initial Screening

• 32 landfills of 121 in the database were recommended for further consideration– Produced red-yellow–green measles chart

• To refine the data, questionnaires were sent to 32 locations; 28 responded

• Scored to reflect completeness of the data received, the year closed, landfill size, % MSW, type of gas management system, and electricity rates

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Scoring and Refining

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Score = (A + (B + C) x D + E) x F; where:

A = Completeness of data set (values = 0, 1, or 2)Not Submitted – 0; Partially Complete – 1; Substantially Complete – 2

B = Closure date (values = 0, 1, 2, 3, or 4)Unknown – 0; Prior to 2001 – 1; 2001-2006 – 2; 2006-2011 – 3; Active – 4

C = Landfill Size (values = 0, 1, 2, or 3)>1.5 m tons (large) – 3; >0.75 m tons (mid) – 2; <0.75 m tons (small) – 1; Unknown – 0

D = Percent Municipal Solid Waste (values = 0, 1, 2, 3, 4, or 5)None – 0; Unknown – 1; <25% - 2; 25-50% - 3; 50-75% - 4; >75% - 5

E = Gas Management System (values = 0, 1, or 2)None – 0; Passive – 1; Active – 2

F = Local electric rate (values in cents/kWh)

Net Zero through Emerging Technologies

Top 11 Candidates after Questionnaire/Scoring

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• Fort Irwin, CA

• Fort Hood, TX*

• Fort Bliss, TX*

• Yuma Proving Ground, AZ

• Fort George G Meade, MD

• Fort Riley, KS

• Fort Belvoir, VA

• Camp Roberts, CA

• Fort Lewis-McChord, WA*

• Sierra Army Depot, CA*

• Fort Pickett, VA*Net Zero Base

Scored better than Fort Pickett but discarded...

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• White Sands Missile Range, CA*• Fort Hunter Liggett, CA*• Fort Sill, OK**• Fort Jackson, SC**

* Lack of a gas collection system, low precipitation levels, and methane monitoring reports showing only a few ppm methane

** Low % MSW, low ($0.06-$0.08/kwh) electric rates

Preliminary Modeling

• Used EPA’s LandGEM software to model potential methane output

• Model estimates savings-to-investment ratio for proposed plant (>1.0 = feasible)– Using data, scoring, modeling results and

discussions with client, further investigation through records review was proposed

– Pickett, Belvoir, Meade, Hood, Yuma, Bliss, Lewis-McChord chosen

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Ex: Fort Meade: Methane Produced vs. Captured, Cells 1 and 2

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Fort Meade:Methane Production by Cell

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Fort Meade: Energy Density

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Refinements from On-site Records Review

• Some electric rates were incorrectly reported, skewing results

• Trade-offs are challenging to evaluate:– Some cultural barriers exist in defending the

“closed landfill” status– Non-attainment areas biased against

installation of new plant equipment

• If you are going to wander around landfills, you need to watch out for ticks

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Location Waste in Place

Closure Year Electric Rates

Annual Precipi-tation

% MSW Gas Collection System

Methane Present?

Fort Meade 0.51m tons Pre-2001 $0.14/kWh 41 in. 83% Passive Yes

Small Bad Good Good Good

Fort Pickett 0.51m tons Pre-2001 $0.10/kWh 43 in. 100% Passive Yes

Small Bad Good Good Good

Fort Hood 3.14m tons Active* $0.053/kWh 32 in. 95% None Yes

Large Good Bad Good Good

Fort Bliss 2.16m tons 2013 $0.08/kWh 9 in. 82% Passive Yes

Large Good OK Bad Good

JB Lewis- McChord

1.20m tons 2004 $0.038/kWh 41 in. 79% Passive Yes

Mid OK Bad Good Good

Results of Records Review, Second Screening

State why Yuma and Belvoir are gone

Design Considerations

• LFG plants have an estimated installed cost of $5000/kW

• The potential plant output from this study group ranges between 250 - 848 kW– Small compared to total base demand– $1.2M - $4.2 M capital investment

• Meade, Hood and Bliss will likely prove to have a reasonable payback period and sites with SIRs> 1.0

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