Southern CompanyBiomass to Electricity Research

Jeremiah HaswellSouthern Company Research & Environmental Affairs

LSU Alternative Energy 2009April 23rd, 2009

Outline

• 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

CC

OPCO Plant Type

GPC

APC

GULF

MPC

SPC

H Weiss Dam

Total 42, 514 MW Total 42, 514 MW

Southern Company “Owned”Southern Company “Owned”

N

S

Combined Cycle (8,359 MW)

H

CT

PA

Nuclear (3,759 MW)

Steam (21,587 MW)

Combustion Turbine (3,992 MW)

Hydro (2,815 MW)

Power Purchase Agreements (2,002 MW)

HLay Dam

HMitchell Dam

H Martin Dam

H Yates Dam

H Thurlow Dam

HSinclair Dam

H Logan Martin Dam

HHolt Dam

HNeely Henry Dam

HHolt Dam

HJordan Dam

HBankhead Dam

HBouldin Dam

H Riverview Dam

H Smith Dam

H Harris Dam

HRocky Mountain

HMorgan Falls Dam

H Langdale Dam

H Bartletts Ferry Dam

H Goat Rock Dam

H Oliver Dam

H North Highlands Dam

H Flint River Dam

H Lloyd Shoals Dam

SPlant McManus

H Wallace Dam

H Barnett Shoals Dam

H Estatoah Dam

H Burton Dam

H Terrora Dam

H Yonah Dam

HNacoochee Dam

HTugalo Dam

HTallulah DamSPlant Gorgas

N Plant Vogtle

S Plant Miller

SPlant Greene County

S Plant Gadsden

SPlant Bowen

SPlant Gaston

SPlant Barry

SPlant Scholz

S Plant Mitchell

SPlant Wansley

S Plant YatesS Plant McDonough

SPlant Scherer

S Plant Hammond

SPlant McIntosh

SPlant Kraft

SPlant Smith

SPlant Watson

SPlant Daniel

SPlant Sweatt

S Plant Eaton

S Plant Crist

N Plant FarleyN Plant Hatch

S Plant Branch

CCStanton Generating Facility

CC Washington County

CC

CC CC Plant Theodore

CC

CCPlant HarrisCCPlant Franklin

CC

CC

CT

DeSoto County Energy Complex

CT Chevron Cogen

CT

CT

CTPlant Wilson

CT Plant Dahlberg

CT Plant RobinsCT

CTPlant Oleander

PA Murray

PA Calhoun

PA Mid-GA Cogen

PA West Georgia

CCRowan County Energy ComplexCT

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

“Global Warming” Articles in Major U.S. Newspapers

0

100

200

300

400

500

600

700

NYTimes

AJC Wash.Post

LATimes

WSJ

1996

2001

2006

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

State renewable portfolio standard

State renewable portfolio goal

www.dsireusa.org / April 2009

Solar water heating eligible *† Extra credit for solar or customer-sited renewables

Includes separate tier of non-renewable alternative resources

WA: 15% by 2020*

OR: 25% by 2025 (large utilities)

5% - 10% by 2025 (smaller utilities)

CA: 20% by 2010

☼ NV: 20% by 2015*

☼ AZ: 15% by 2025

☼ NM: 20% by 2020 (IOUs)

10% by 2020 (co-ops)

HI: 20% by 2020

☼ Minimum solar or customer-sited requirement

TX: 5,880 MW by 2015

UT: 20% by 2025*

☼ CO: 20% by 2020 (IOUs)10% by 2020 (co-ops & large

munis)*

MT: 15% by 2015

ND: 10% by 2015

SD: 10% by 2015

IA: 105 MW

MN: 25% by 2025(Xcel: 30% by 2020)

☼ MO: 15% by 2021

IL: 25% by 2025

WI: Varies by utility;

10% by 2015 goal

MI: 10% + 1,100 MW by 2015*

☼ OH: 25% by 2025†

ME: 30% by 2000New 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

☼ NY: 24% by 2013

☼ NJ: 22.5% by 2021

☼ PA: 18% by 2020†

☼ MD: 20% by 2022

☼ DE: 20% by 2019*

☼ DC: 20% by 2020

VA: 12% by 2022*

☼ NC: 12.5% by 2021 (IOUs)

10% by 2018 (co-ops & munis)

VT: (1) RE meets any increase in retail sales by

2012; (2) 20% RE & CHP by 2017

28 states have an RPS

5 states have goals

US Wind Resources

Source: Wind Energy Atlas of the United States (NREL)

Solar Intensity: United States

US Geothermal Resources

• An economic resource however limited based upon geology

Source: US Department Of Energy

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– 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

• Mill Amps increased 10 – 15% with wood addition• Mill motors require spare capacity to carry higher amps

200

220

240

260

280

300

320

300 350 400 450 500 550 600

Steam Flow (Klb/hr)

Avera

ge M

ill

Am

ps

0% wood

10% wood

8% wood

15% wood

Linear (0% wood)

Linear (10% wood)

Linear (15% wood)

Boiler Efficiency Results

• 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

80

81

82

83

84

85

86

3 4 5 6 7

Economizer Out O2 (%)

Bo

iler

Eff

icie

ncy

(%

)

0 full

10% full

8% full

15% full

10% clean

15% clean

Small Wood Chips Co-millingSummary 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 Tippers2 Screens and Hogs

Stacker / Reclaimer

Boiler House Retrofit Requirements

Install:– 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

– August 22, 2008 Filed with GA PSC– December 2008 Air permit filed with EPD– March 17, 2009 PSC Unanimous Approval, 5 -0– March 2010 Final air permit expected– April 2011 Retrofit construction begins– June 2012 Begin operations

• 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.

SE Renewable Energy Potential

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