Transcript Southern Company Biomass to Electricity Research Jeremiah Haswell Southern Company Research & Environmental Affairs LSU Alternative Energy 2009 April 23rd, 2009

Southern Company
Biomass to Electricity Research
Jeremiah Haswell
Southern Company Research & Environmental Affairs
LSU Alternative Energy 2009
April 23rd, 2009
Outline
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Southern Company Introduction
Renewable Portfolio Standards
Renewable Options in the Southeast
Biomass Co-Firing Research
Plant Mitchell
Questions
Southern Company
• Premier super-regional energy company
in the Southeast U.S. and a leading U.S.
producer of electricity
• Reputation for
– excellent customer satisfaction
– high reliability
– retail electric prices that are
15% below national average
• Consistently highly ranked on
Fortune magazine’s list of
“America’s Most Admired Companies”
• 4.2 million customers, representing 12 million people
• 120,000 square miles of service territory
• 40,000+ MW of generating capacity
Southern Company “Owned”
Rowan County Energy Complex CC
CT
H Estatoah Dam
Nacoochee Dam H
H Weiss Dam PA Murray
H Burton Dam
Tugalo Dam H
H Terrora Dam
Rocky Mountain H
Tallulah Dam H
S Plant Gadsden
H Smith Dam
H Yonah Dam
Plant Gorgas S
S Plant Hammond
Neely Henry Dam H
Plant Bowen S
CT Plant Dahlberg
S Plant Miller
Morgan Falls Dam H
H Barnett Shoals Dam
H Logan Martin Dam
Bankhead Dam H
S Plant McDonough
Plant Gaston S
S Plant Yates
Holt Dam H
PA Calhoun
H Wallace Dam
S
Lay Dam H
H Harris Dam CC Plant Wansley H Lloyd Shoals Dam
CT
Holt Dam H
Plant Wilson
Mitchell Dam H
Sinclair Dam H
Plant Scherer S
Plant Greene County S
Jordan Dam
CT
H
Bouldin Dam H
H Martin Dam
H Langdale Dam
H Yates Dam
H
North Highlands
Dam
H Flint River Dam
CC Washington County
S Plant Mitchell
N Plant Farley
Plant Barry S
Plant Watson S
OPCO
CC
CC Plant Theodore
CT Chevron Cogen
Plant Type
N Nuclear (3,759 MW)
Plant McIntosh S
CT
CC
Plant Kraft
S
CT
N Plant Hatch
Plant McManus S
CC
Plant Daniel S
N Plant Vogtle
Thurlow Dam
Plant Sweatt S
S Plant Eaton
S Plant Branch
CT Plant Robins
H Bartletts Ferry Dam PA Mid-GA Cogen
H Goat Rock Dam
PA West Georgia
Plant Franklin CC H Oliver Dam
H
Plant Harris CC
H Riverview Dam
Plant Scholz S
S Plant Crist
CC
Plant Smith
S
APC
Stanton Generating Facility CC
S Steam (21,587 MW)
GPC
Plant Oleander CT
CC Combined Cycle (8,359 MW)
GULF
CT Combustion Turbine (3,992 MW)
MPC
SPC
H Hydro (2,815 MW)
PA Power Purchase
Agreements (2,002 MW)
Total 42, 514 MW
CT
DeSoto County Energy Complex
Renewable Drivers
• Current renewable power drivers:
– The political and societal movements toward capping CO2
emissions from power plants to curtail global warming
– State and Federal Renewable Portfolio Standards
– Cost and dependence on imported fuels
– Current Administration’s Agenda
Climate Change
700
600
500
400
1996
2001
2006
300
200
100
0
NY
Times
AJC
Wash.
Post
LA
Times
WSJ
“Global Warming” Articles in
Major U.S. Newspapers
Renewable Portfolio Standards (RPS) or
Renewable Electricity Standard (RES)
• Currently 28 of the 50 US states and the District of
Columbia have adopted a RPS.
– RPSs range from 105 MW in Iowa to 25% by 2025 in
Oregon.
• Nationally there are multiple proposed bills:
– Binghaman – 20% by 2020, Efficiency up to 5%, 5M MWh
and up.
– Markey – 25% by 2025, no EE, 1M MWh and up.
Renewable Portfolio Standards
www.dsireusa.org / April 2009
WA: 15% by 2020*
MT: 15% by 2015
(Xcel: 30% by 2020)
MI: 10% + 1,100 MW
ND: 10% by 2015
OR: 25% by 2025 (large utilities)
VT: (1) RE meets any increase
in retail sales by 2012;
(2) 20% RE & CHP by 2017
MN: 25% by 2025
by 2015*
5% - 10% by 2025 (smaller utilities)
SD: 10% by 2015
WI: Varies by utility;
10% by 2015 goal
☼ NV: 20% by 2015*
IA: 105 MW
UT: 20% by 2025*
CA: 20% by 2010
☼ CO: 20% by 2020 (IOUs)
10% by 2020 (co-ops & large munis)*
☼ AZ: 15% by 2025
☼ NY: 24% by 2013
☼ OH: 25% by 2025†
New RE: 10% by 2017
☼ NH: 23.8% by 2025
☼ MA: 15% by 2020
+ 1% annual increase
(Class I Renewables)
RI: 16% by 2020
CT: 23% by 2020
☼ PA: 18% by 2020†
IL: 25% by 2025
VA: 12% by 2022*
☼ MO: 15% by 2021
☼ NC: 12.5% by 2021
(IOUs)
10% by 2018 (co-ops & munis)
☼ NM: 20% by 2020 (IOUs)
ME: 30% by 2000
☼ NJ: 22.5% by 2021
☼ MD: 20% by 2022
☼ DE: 20% by 2019*
☼ DC: 20% by 2020
10% by 2020 (co-ops)
TX: 5,880 MW by 2015
HI: 20% by 2020
State renewable portfolio standard
State renewable portfolio goal
Solar water heating eligible
28 states
have an RPS
☼
*†
Minimum solar or customer-sited requirement
5 states have goals
Extra credit for solar or customer-sited renewables
Includes separate tier of non-renewable alternative resources
US Wind Resources
Source: Wind Energy Atlas of the United States (NREL)
Solar Intensity: United States
US Geothermal Resources
Source: US Department Of Energy
• An economic resource however limited based upon geology
Bioenergy
• Energy derived from Biomass
• Biomass is defined by Ralph Sims as “recent organic
matter originally derived from plants as a result of the
photosynthetic conversion process, or from animals,
and which is destined to be utilized as a store of
chemical energy to provide heat, electricity, or
transport fuels”
• Biomass is an abundant resource in the Southeast.
• 21,000 MW worldwide (8,300 MW US) - 2005
Biomass to Electricity Options
• Co-firing
– Co-Milling
– Direct Injection (DI)
• Dedicated Biomass Plants
– Biomass Repowering of an existing unit
– Brownfield or Greenfield sites
• Biomass Gasification - DI, CT, CC
• Biodiesel Co-firing in CT’s or boilers
Co-Milling Project Objectives
• Determine the costs and
benefits of co-firing whole tree
green wood chips on:
– power plant fuel handling
– combustion efficiency
– and air emissions
• Determine cost and feasibility
of harvesting trees for co-firing
fuel in an existing coal fired
boiler.
Small Wood Chips Co-milling
• Mix biomass with coal and introduce into the boiler
through coal handling system
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Little or no capital investment
Low co-firing percentages (1 to 5% by energy input)
Tested at Plant Gadsden 1 & 2 - Fall 2007, Spring 2008
Plant Greene 1& 2 County - Fall 2008
Spring 2009 – Barry 2
• Watson 4 & 5
• Gaston 3, Gorgas 6
Cutting & Chipping Trees
Talladega National Forest
Precision Husky Modified
Drum Chipper
Small Wood Chips Co-milling
Results – Mill Amps
320
0% wood
10% wood
Average Mill Amps
300
8% wood
15% wood
Linear (0% wood)
280
Linear (10% wood)
Linear (15% wood)
260
240
220
200
300
350
400
450
500
550
600
Steam Flow (Klb/hr)
• Mill Amps increased 10 – 15% with wood addition
• Mill motors require spare capacity to carry higher
amps
Boiler Efficiency Results
86
85
Boiler Efficiency (%)
• Reduced dry gas loss
offsets increased
moisture losses with
wood.
• 10% wood Co-firing
about the same
efficiency as coal
• 15% wood Co-firing
between 0.0 - 0.7 %
lower than coal
84
0 full
83
10% full
8% full
82
15% full
10% clean
81
15% clean
80
3
4
5
Economizer Out O2 (%)
6
7
Small Wood Chips Co-milling
Summary of Results from Plant Gadsden
• Small wood chips
successfully co-fired at 3 to
5% energy input
• Emissions were unchanged
(NOX and CO) or reduced
(CO2, SO2, Hg)
• Boiler efficiency unaffected
at 3%, slightly lower at 5%
co-firing
Plant Gadsden Direct Injection System
• Alabama Power Renewable Energy Rate
– 2.25 cents for 50 kwh block
– Customers sign up for X blocks for 12 months
– Two 1,000-pound bales of switchgrass generate 1,000 kilowatt-hours
of electricity - enough to power an average home for a month.
Plant Gadsden Direct Injection System
• Can co-fire up to
10% by energy.
• Research
system – limited
to 7,000 lb/hr.
Biomass Repowering
• Proven at other sites
– Plant Schiller 50 MW conversion
• Biomass plants have the advantage of being able to
be dispatched like typical fossil fuel plants
• Accepted as CO2 neutral
• More cost competitive than Greenfield sites
– $1400 – 2000 /kW vs. $4000 / kW
• Direct replacement for coal generation capacity
Plant Mitchell
http://www.youtube.com/user/GeorgiaPowerChannel
Mitchell Biomass Re-powering Study
• T-fired PC Boiler (CE), built in 1962, Single Reheat
– 165 MW gross, 156 MW net
– Full Load Coal Flow: 60 ton/hr
– 40 ft x 26 ft boiler plan area – limiting parameter
– 1875 psig, 1000oF, 1,075,000 lb/hr
– Coal Bunker Capacity:
• 1630 tons, 27 hours
– 30+ day On-site Coal Supply
– Existing emissions controls
• ESP, 1% S coal
Plant Layout
Mitchell Woodyard Concept #1 – Linear Piles
Mitchell Woodyard Concept #2 – Circular Piles
4 Truck Tippers
2 Screens and Hogs
Stacker / Reclaimer
Boiler House Retrofit Requirements
Install:
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Wood chip delivery system
Stoker grate
Air supply ductwork, including new booster fans for fuel distributors
Replace furnace bottom, pressure parts, etc.
Bottom ash collection system
Grate cooling water supply
Foundation upgrades
Install multi-clone between economizer and air heater (1 ea. path)
New retractable sootblowers for air heaters (1 each)
Controls
Mitchell Unit 3 with DSC Vibrating Hydrograte
Air Swept Spouts for Biomass Fuels
Environmental Controls
• Existing ESP is adequate
• Multiclones would be added
to remove large particulates
and re-inject them for
additional fuel burning
• Large reductions in NOx,
SOx, Hg, CO2 emissions
100% Biomass Operation
• Capacity:
– 96 MW net w/ new Stoker Grate and Suspension Firing
– Heat Rate ~ 12,500 Btu / Hr
• Approx. 1.1 million ton/yr biomass use
– Biomass delivery would be on the order of 160 trucks per day for a
5.5 day delivery schedule.
• Timeline
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August 22, 2008
December 2008
March 17, 2009
March 2010
April 2011
June 2012
Filed with GA PSC
Air permit filed with EPD
PSC Unanimous Approval, 5 -0
Final air permit expected
Retrofit construction begins
Begin operations
SE Renewable Energy Potential
• Wind has small capacity potential in the southeast
• Solar photovoltaics has very high cost and requires
large land area
• Landfill methane can be cost competitive, but has
small capacity potential
• Biomass has higher capacity potential in the
southeast. Co-firing and converting an existing plant
have lower costs than a new biomass facility.
Summary
• State and National RPS are more of a when than why.
• Biomass is the most economical option in the
Southeast
• Southern Company must develop a comprehensive
list of possible solutions which includes all forms of
renewable generation.
Questions
If we knew what we were doing, it wouldn't be called
research, would it?
- Albert Einstein