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Should We Use Wood for Energy?An Introduction
Brief History: Energy in the U.S.
Source: EIA, 2007
Brief History: Energy in the U.S.
Energy Consumption by Source (1635-2000)
INSERT GRAPH
Source : EIA, 2007
Nonrenewable Energy
• Finite resources – Cannot be replenished over a short
period of time
• Fossil fuels– Fossilized remains of plants and animals
found in top layers of Earth’s crust– Coal, petroleum, and natural gas– In 2006, 86% of energy consumed in U.S.
produced with fossil fuels (U.S. EIA, 2006)
• Uranium (nuclear energy)
Renewable Energy
• Not depleted or can be replenished over a short period of time– Solar– Wind– Biomass– Hydroelectric– Geothermal
Photos courtesy of NREL
Renewable Energy: Future Trends
Source: EIA, 2008 (www.eia.doe.gov/oiaf/aeo/production.html)
Brainstorm
• What are some of the potential advantages and disadvantages to using: – nonrenewable energy sources?– renewable energy sources?
• How many strategies can we use to improve the energy situation?
Biomass
• Biological material from plants or animals that is either living or was recently living (Environmental Literacy Council, 2008)
– Food crops (sugar, corn, wheat)
– Grassy and woody plants– Agricultural and forestry
residues– Municipal and industrial solid
wastes– Landfill gas
Photo courtesy of NREL
Woody Biomass
• Plant material from trees and shrubs: roots, bark, leaves, branches, limbs, trunks, and vines
• Some sources of woody biomass – Urban waste wood
• Yard trimmings• Storm damage• Land-clearing debris
– Forestry residues• Thinning for forest health and wildfire,
disease, insect pest risk reduction• Ecosystem restoration• Branches from harvesting
– Wood grown for energy• Short rotation woody crops
Questions to Explore
• What do you know about using wood for energy?
• What do you need to know in order to make informed decisions regarding using wood for energy in your community?
• What do you think are some of the major issues associated with using wood for energy?
Potential Advantages of Using Wood for Energy
• Local and renewable resource
• Creates local jobs
• Can help keep land in forests
• Useful way to process “waste wood”
• Thinning results in healthier forests
• Can produce lower levels of sulfur, nitrogen, and heavy metals such as mercury than coal
• Carbon-neutral energy source
The Carbon Cycle
Potential Disadvantages of Using Wood for Energy
• Cannot meet all energy demands
• Challenges of transportation and storage
• Reduction of highly valued forests– Products– Landscapes– Recreation– Wildlife habitat– Watershed protection
• Concerns about air emissions
• Impacts on soil fertility, water quality
• Concerns about long-term availability
Harnessing Energy from Wood
• Break down cellulose in wood to release energy
• Uses of energy from wood– Generate electricity– Heat buildings with water, steam,
or air– Produce steam for industrial
purposes– Transportation fuels
Wood Conversion Technologies
• Direct combustion• Gasification• Anaerobic digestion• Pyrolysis• Fermentation• Alcoholysis
Photos courtesy of NREL
Wood Conversion Products
• Biogas• Bio-oils• Biodiesel• Ethanol• Wood pellets
Photos courtesy of NREL
Biogas
Bio-oils
BIO-OILS
HEAT POWER FUELS
BoilerCo-firing
Diesel engineMicro-turbineStirling engine
Biodiesel
Biodiesel
Canola
Soybean
Peanuts
Tung Oil Tree
Chinese Tallow (Popcorn Tree)
Chlorella
Switch Grass
Wood Chips and Residue
Giant Miscanthus
Ethanol
Sugarcane
Sweet Sorghum
PINE
EUCALYPTUS
WOOD RESIDUE
SMALL DIAMETER STEMS
Pellets
THINNING RESIDUE
Wood Pellets in the Southeast
EUROPE
FLORIDA
GEORGIA
Wood Pellets in Europe• Finland
– World leader in bio-energy generation (30% of total primary energy consumption)
• Sweden– World largest producer, importer, and consumer of wood
pellets– Pellet production in Sweden increases 25 to 30% every year– From 270 municipalities that have district heating systems,
250 use biomass fuels, mostly wood pellets
Case Study: Co-firing with Wood and Switchgrass
• Gadsden Steam Plant in northeastern Alabama
• Run by Alabama Power, subsidiary of Southern Company
• Uses switchgrass from a local farmer and wood from forest thinning, wood processing, and harvest residues
Case Study: Innovative Fuel Sources Generate Success
Telogia Power facility near Tallahassee, Florida
Telogia Power, LLC
• In operation since 1988• Liberty County, Florida• Currently supplies electricity to Seminole Electric• 14 MW gross electricity production• Fuel—190,000 tons/year
Wood (yard waste, forest management debris, timber harvest residues)
Paper waste (diaper tailings, unfit currency, confidential documents)
Occasionally more unusual sources such as contaminated peanut butter
Important Questions
• What factors should be considered?• How can a community address all of
these factors?
Sustainability
• Sustainable decisions are those that consider current and future impacts on three components: environment, economy, and society
Is Using Wood for Energy Sustainable?
• Brainstorm current and future impacts of using wood for energy on the environment, economy, and society
Many Factors to ConsiderEnvironmentalHabitat changeAir qualityWater qualitySoil fertilitySustainable management
EconomicLocal jobsCost of electricityCost of facilitySupply of woodCost of wood
SocialPublic healthQuality of lifePublic involvementFair decisionsValuesSense of place
Technical Conversion process Co-firing Transportation options Storage
Systems Thinking and Critical Thinking
• Systems thinking– Consider the whole picture– Think about all the parts of the system and how
they interrelate
• Critical thinking– Analysis– Synthesis– Evaluation
"We can't solve problems by using the same kind of thinking we used when we created them.“ - Albert Einstein
Should our community use wood for energy?