This document discusses a next generation swine waste-to-energy project in North Carolina. It summarizes that NC is a top pork producing state that has adopted renewable energy standards requiring utilities to source 12.5% of energy from renewable sources by 2021. A case study is presented on the Loyd Ray Farms project that converts waste from 9,000 pigs into electricity using anaerobic digestion. The project generates renewable energy credits and carbon offsets while improving waste management and air/water quality on the farm. Initial results found the project generated 344 renewable energy credits and 2,500 carbon offsets, meeting or exceeding environmental performance standards for nutrients, odors, and pathogens. Ongoing challenges include issues with the gas conditioning system and
Next-gen renewable energy turns NC swine waste into electricity
1. Next Generation Technology
Swine Waste-to-Energy Project
Renewable Energy Generation and
GHG Emission Reductions via
Innovative Waste Management
Presented To:
From Waste to Worth:
“Spreading” Science & Solutions
April 4, 2013
Presented By:
William G. “Gus” Simmons, Jr., P.E.
Cavanaugh & Associates, P.A.
1
2. Why is NC Looking at Alternative
Energy / Fuels from Ag Waste???
• NC Ranks 2nd in the US in pigs produced, with
15% of the US pig crop (IA)
• NC Ranks 2nd in the US in turkeys
produced, with 13% of the US turkey crop
(MN)
• NC Ranks 4th in the US in broilers
produced, with 9% of the US broiler crop (GA)
• NC Ranks 10th in the US in residential
electricity consumption, per capita
2
3. So, Why Agricultural WTE in NC???
• With the passage of Senate Bill 3 (2007), North Carolina
became the first state in the Southeast to adopt a Renewable
Energy and Energy Efficiency Portfolio Standard (REPS).
• SB3 requires:
– investor-owned utilities in North Carolina to provide up to 12.5% of
their energy through renewable energy resources or energy efficiency
measures.
– Rural electric cooperatives and municipal electric suppliers are subject
to a 10% REPS requirement.
• Agree or Disagree – a linkage was made between the
potential for the development of renewable energy (biogas /
biomass) and all the pig farms in North Carolina
3
4. NC IOU* Renewable Obligation**
4
* Investor Owned Utility
** Under Senate Bill 3
Year Total REPS Solar Swine
Waste
Poultry
Waste
2010 0.02%
2012 3% 0.07% 0.07% 170k MWh
2013 700k MWh
2014 900k MWh
2015 6% 0.14% 0.14%
2018 10% 0.20% 0.20%
2021 12.5%
Out of State REC Cap = 25% of Requirement
To meet obligations of SB3, Duke Energy would need ~123,000 MWh of Swine
Waste Fueled Electricity Needed by 2018 (pre-merger values)
5. North Carolina Swine Energy Potential
Data provided by Duke University Carbon Offsets Initiative 5
Asheville
Triad Raleigh/RTP
Charlotte Wilmington
6. The North Carolina Potential -
What Can We Expect from Swine
Waste to Energy Systems?
• About 1.1 M MWh electricity annually
• About 6.3 M tons GHGs reduced annually
• Potential for major nutrient management
strides and pathogen reductions
• Improved animal health, reduced
mortalities, greater farm productivity
• Creation of new acres of cash cropland
Data provided by Duke University Carbon Offsets Initiative
6
8. Case Study:
Digester Systems for
Animal Waste Solids –
Loyd Ray Farms Project
GHG Emission
Reductions and
Renewable Energy
Generation via
Innovative Waste
Management
8
9. Step 1: Establish the Target
Project Goals: (2006)
• Make it “Market Feasible” – farm owners perspective
• Energy Generation + Water Quality Improvement + Air
Emissions Improvement
• Make it flexible - different farm sizes & types
• Process based, not technology based
• Innovative waste management : Achieve
environmental performance standards as described by
NC legislation
– Substantial elimination of odor, ammonia, total
nitrogen, and pathogens
9
17. Gas Conditioning
System &
Microturbine
Microturbine Specifications:
•65 kilowatt Generative Capacity
•First Scheduled Service @ 8,000 Hrs
•Only one moving part @ >90,000 RPM
•Air bearings – no lubricant or coolant required
17
18. Expected Outcomes:
5,000± Carbon Offsets per Year, registered with Climate Action
Reserve
Duke University & Google: Retire to meet carbon neutrality
goal, retire for immediate internal demand, and/or sell when
strong market signal arises
500± Renewable Energy Credits per Year
Utility: Motivated by NC Renewable Energy and Energy
Efficiency Portfolio Standard Swine Waste Set Aside
Electricity Generation
Farm: Energy to offset increased demand from innovative
system and offset baseline electricity demand (projected to
offset up to half of farm’s existing electricity demand)
Compliance with Environmental Performance Standards for New
& Expanded Swine Farms
(ammonia, nutrients, pathogens, odors, metals and zero discharge
of waste to surface and groundwater); Ensures compliance with
offset standard to meet all air and water quality standards by
controlling nutrient loads 18
22. Scorecard
22
Parameter Goal Actual Success Gauge
RECs
learned that we have more potential
500 344 69%
Carbon Offsets
deductions due to venting, metering
5,000 Tons 2,500 Tons 50%
Environmental Performance
- Surface Water Protection
Substantial Elimination Accomplished
by Permit
Passed
Environmental Performance
- Ground Water Protection
Substantial Elimination Accomplished
by Permit
Passed
Environmental Performance
- Odor Emissions
>7:1 D/T 2:1 D/T Passed
Environmental Performance
- Ammonia Emissions
WWTP =
Farm =
106 kg/wk
476 kg/wk
23 kg/wk
341 kg/wk
460% (Passed)
140% (Passed)
Environmental Performance
- Vector Reduction
<7,000 mpn/100mL <5,000
mpn/100mL
140%
(Passed)
23. Costs and Benefits
Costs
• Capital: $1.7M
• O&M: $80,000/year
Funding sources
• NCACSP LCP
• CCPI/EQIP
• Sale of RECs to Utility
• Sale of Carbon Offsets
(voluntary market)
• Note: No capital or operating
costs passed on to farm owner!
Farm owner receives excess
electricity!!!
Benefits
• Cash flow for farm owner
• Improved animal health
• Other ecosystem services (N, P
control)
• Variability in nitrogen output for
fertilizer
• Reduced sludge management
cost
• Improved air quality on-site
• Reduction of odors off site
• More choice in cropping plan
• Sustaining NC Agriculture
• Reduced GHG Emissions
23
24. A couple of firsts…
• First Swine Waste-to-energy project in the
State of North Carolina to place RECs on the
North Carolina Utilities Commission REC
Tracking System
• First Transfer of RECs from a NC Swine Farm to
Duke Energy
• First ‘Innovative Swine Waste Treatment
System’ permitted that utilizes digester
• First Expansion Permit Since 1997???
24
25. Ongoing Research & Analysis:
• Digester Performance – DU is conducting continuous
research of digester biogas composition, loading rates, and
carbon destruction efficiency (monthly)
• Environmental System Performance – Water
quality analysis by DU and Private Labs (monthly / quarterly)
• Emissions – DU performing flux analysis of ammonia and
odor emissions (twice annually)
• Animal Productivity – Mortality rates, feed conversion
rates, days to market, etc.
• Economic Performance – DU / DE / Cavanaugh
25
26. Challenges & Lessons Learned:
• Gas Skid Challenges – Gas skid has suffered from
multiple outages, which prevents REC generation. Numerous
issues with gas skid controls system and condensate removal.
• Abundance of Gas – Very conservative on gas
production expectations – have not been able to utilize all gas
produced.
• Electrical Load Balancing – Environmental system
operating at full capacity requires more electricity (demand)
than MT produces. Adjusted operational schedule to resolve.
• CAR Protocol Requirements – Adding additional gas
flow meters, thermocouples on flare, etc.
26