Univ. of Phoenix SCI/256

Week 3Chapter 11-14 and 17-20

Food and Energy

How is Land Distributed Globally?How is Land Distributed Globally?

Not that long ago, Not that long ago, natural areas were natural areas were considered essentially considered essentially limitless. Now, limitless. Now, emphasis is on emphasis is on preservation of natural preservation of natural areas. How much of areas. How much of that 37% is enough?that 37% is enough?

What Is To Be Done?What Is To Be Done?

1.1. Encourage reassessment of taxes on private Encourage reassessment of taxes on private agricultural land near urban centers.agricultural land near urban centers.

2.2. Require thorough public review and planning of Require thorough public review and planning of land use. Review procedures of long-standing.land use. Review procedures of long-standing.

3.3. Balance interests in management of Federal lands.Balance interests in management of Federal lands.Wise-use movementWise-use movementEnvironmental movementEnvironmental movement

Food Crops and BiodiversityFood Crops and Biodiversity

Human beings have used about five thousand species of plants as food, but only 150 or so have entered world commerce.

Fifteen crops provide most of the world's food, and three crops - wheat, rice, and maize - account for roughly 60 percent of the calories and 56 percent of the protein that humans consume directly from plants.

Food Crops and BiodiversityFood Crops and Biodiversity

Forty percent of an estimated 2,300 species of cultivated Forty percent of an estimated 2,300 species of cultivated plants belong to just four families: Graminae (grasses), plants belong to just four families: Graminae (grasses), Leguminosae (legumes), Rosaceae (apples, pear, etc.), and Leguminosae (legumes), Rosaceae (apples, pear, etc.), and Solanaceae (potatoes).Solanaceae (potatoes).

The grass family - including The grass family - including such crops as wheat, rice, such crops as wheat, rice, maize, barley, sorghum, maize, barley, sorghum, millet, oats, and rye - provides millet, oats, and rye - provides some 80 percent of calories some 80 percent of calories consumed by humans.consumed by humans.

Origins of Major Food CropsOrigins of Major Food Crops

Many of the major food crops originated in regions that Many of the major food crops originated in regions that are not particularly species rich. Crops were are not particularly species rich. Crops were domesticated in warm temperate and subtropical zones domesticated in warm temperate and subtropical zones and in tropical mountainous regions. and in tropical mountainous regions.

Wheat and barley were first grown in the steppes and Wheat and barley were first grown in the steppes and woodlands of southwestern Asia, and the origin of maize woodlands of southwestern Asia, and the origin of maize has been traced to the seasonally dry central highlands of has been traced to the seasonally dry central highlands of Mexico. The highlands of Peru contributed the tomato Mexico. The highlands of Peru contributed the tomato and potato (though the tomato was probably first and potato (though the tomato was probably first cultivated in Mexico). cultivated in Mexico).

Origins of Major Food CropsOrigins of Major Food Crops

Most important food crops appear to have originated Most important food crops appear to have originated where seasons are pronounced. In part this is due to the where seasons are pronounced. In part this is due to the tendency of plants in seasonal environments to store tendency of plants in seasonal environments to store nutrients during the growing season. Often, these nutrients during the growing season. Often, these reserves are what human eat. reserves are what human eat.

Much of the Much of the world's world's agriculture is agriculture is based on based on introduced introduced crops.crops.

Origins of Major Food CropsOrigins of Major Food Crops

In developing countries in the Americas, only 32 percent In developing countries in the Americas, only 32 percent of production is of crops of American origin.of production is of crops of American origin.

The comparable figure for African developing countries The comparable figure for African developing countries is 30 percent of crop production is native plants. is 30 percent of crop production is native plants.

Only in Asian developing countries is most production - Only in Asian developing countries is most production - 70 percent - by native species. 70 percent - by native species.

Origins of Major Food CropsOrigins of Major Food Crops

Dependence on introduced species reaches its extreme in Dependence on introduced species reaches its extreme in Australia, the Mediterranean, northern Europe, northern Australia, the Mediterranean, northern Europe, northern Asia, and the United States and Canada. In these Asia, and the United States and Canada. In these regions, more than 90 percent of production is derived regions, more than 90 percent of production is derived from introduced species. None of the world's fifteen from introduced species. None of the world's fifteen most important food crops are native to Australia or to most important food crops are native to Australia or to North America north of Mexico.North America north of Mexico.

World Food IssuesWorld Food Issues

Amounts (famine)Amounts (famine)

DistributionDistribution

PovertyPoverty

Types of food available (malnourishment Types of food available (malnourishment compared to undernourishment)compared to undernourishment)

Grain Grain ProductionProduction

Conclusion – at the Conclusion – at the moment supply moment supply keeping up with keeping up with population growth.population growth.

World World Production Production Major Food Major Food

CropsCrops

Regional Differences in Food Regional Differences in Food ProductionProduction

Regional Regional Differences in Differences in

Food Food AvailabilityAvailability

Distribution of FoodDistribution of Food

Most of the 183 countries of the world are now to some Most of the 183 countries of the world are now to some degree dependent on food imports. These imports come degree dependent on food imports. These imports come from cereal surpluses produced in only a few countries from cereal surpluses produced in only a few countries that have a relatively low population density and intensive that have a relatively low population density and intensive agriculture. agriculture.

For instance, in the period 1989-1991, the United States, For instance, in the period 1989-1991, the United States, Canada, Australia and Argentina provided about 81% of Canada, Australia and Argentina provided about 81% of net cereal export on the world marketnet cereal export on the world market

Differences in Food UsageDifferences in Food Usage

Rice, which has origins in either India or China, is the Rice, which has origins in either India or China, is the eighth most important crop in the developed world (by eighth most important crop in the developed world (by weight). weight).

However, rice is by However, rice is by a factor of two the a factor of two the leading crop in the leading crop in the developing world, developing world, and it is the most and it is the most important source of important source of calories in tropical calories in tropical developing developing countries.countries.

Cassava is a high-Cassava is a high-yield, starchy, low yield, starchy, low protein (<1%) protein (<1%) staple.staple.

Similarly to rice, cassava (manioc) - native to tropical Similarly to rice, cassava (manioc) - native to tropical America - is not grown in developed countries but is the America - is not grown in developed countries but is the fourth most important crop in the developing world (by fourth most important crop in the developing world (by weight) and provides more than half of the caloric weight) and provides more than half of the caloric requirements for over 420 million people in 26 tropical requirements for over 420 million people in 26 tropical countries. countries.

Differences in Food UsageDifferences in Food Usage

Food Resources - FiguresFood Resources - Figures

Over the past 20 years World food production has Over the past 20 years World food production has increased by 2.1% per year. increased by 2.1% per year.

There is enough food globally to give everyone 2,700 There is enough food globally to give everyone 2,700 calories per day. The minimum requirement is 2,100 calories per day. The minimum requirement is 2,100 calories per day and malnourishment is considered to calories per day and malnourishment is considered to be anything lower than 1,800 calories per day.be anything lower than 1,800 calories per day.

In the developing countries of the world one in five In the developing countries of the world one in five people do not have enough food to meet their daily people do not have enough food to meet their daily requirements.requirements.

Take Home MessageTake Home Message

One person dies each and every One person dies each and every second from starvation and its related second from starvation and its related diseases. Three-quarters of those are diseases. Three-quarters of those are children under the age of five. Three children under the age of five. Three children died in the time it took you children died in the time it took you to read this short paragraph.to read this short paragraph.

Global food production outstrips the population!!!!!Global food production outstrips the population!!!!!

Yet, 800 million people are malnourished!!!!!Yet, 800 million people are malnourished!!!!!

Number of Undernourished People Number of Undernourished People (1969-1997)(1969-1997)

Undernourished people (millions)Undernourished people (millions)

1969-711969-71 1979-811979-81 1990-92 1995-971995-97

Sub-Saharan AfricaSub-Saharan Africa 8989 126126 164164 180180

Near East & North AfricaNear East & North Africa 4545 2222 2626 3333

East & South-East AsiaEast & South-East Asia 504504 406406 283283 241241

South AsiaSouth Asia 267267 338338 299299 284284

Latin America & CaribbeanLatin America & Caribbean 5454 4646 5959 5353

Industrialized countriesIndustrialized countries n/an/a n/an/a 99 88

Countries in transitionCountries in transition n/an/a n/an/a 2020 2626

TOTALSTOTALS 959959 938938 860860 825825

Source: FAO (1999)Source: FAO (1999)

Distribution of MalnourishmentDistribution of Malnourishment

FarmingFarming

General Types of AgricultureGeneral Types of Agriculture

In highly developed countries the main type of agriculture In highly developed countries the main type of agriculture is is high-input agriculturehigh-input agriculture (i.e., lots of energy, fertilizers, (i.e., lots of energy, fertilizers, pesticides) which produces high yields.pesticides) which produces high yields.

In developing countries In developing countries practice practice subsistence subsistence agricultureagriculture, which does , which does not produce enough not produce enough surplus crops to sell or to surplus crops to sell or to store for later need.store for later need.

USA Grain YieldsUSA Grain Yields

Typical Agriculture in the US

Types of Subsistence AgricultureTypes of Subsistence Agriculture

Slash and burn (aka shifting agriculture)Slash and burn (aka shifting agriculture)

Nomadic herding - mainly in the areas of Nomadic herding - mainly in the areas of Northwest Asia, the Middle East, North Africa Northwest Asia, the Middle East, North Africa and the Arctic Tundra. and the Arctic Tundra.

PolyculturePolyculture

Genetic Diversity in Food CropsGenetic Diversity in Food Crops

Genetic diversity can enhance crop production. Several Genetic diversity can enhance crop production. Several varieties can be planted in the same field to minimize crop varieties can be planted in the same field to minimize crop failure, and new varieties can be bred to maximize failure, and new varieties can be bred to maximize production or adapt to adverse or changing conditionsproduction or adapt to adverse or changing conditions

As important as genetic diversity is to increasing yields, it As important as genetic diversity is to increasing yields, it is at least as important in maintaining existing productivity is at least as important in maintaining existing productivity because of factors like coevolution.because of factors like coevolution. Over 400 species of Over 400 species of pests now resist one or more pesticides, and the proportion pests now resist one or more pesticides, and the proportion of U.S. crops lost to insects has approximately doubled - to of U.S. crops lost to insects has approximately doubled - to 13 percent - since the 1940s, even though pesticide use has 13 percent - since the 1940s, even though pesticide use has increased. increased.

History of Plant BreedingHistory of Plant Breeding

An Assyrian relief carving from 870 B.C. showing artificial pollination of date palms.

For several thousand years, For several thousand years, farmers have been altering farmers have been altering the genetic makeup of the the genetic makeup of the crops they grow. Human crops they grow. Human selection for features such as selection for features such as faster growth, larger seeds or faster growth, larger seeds or sweeter fruits has sweeter fruits has dramatically changed dramatically changed domesticated plant species domesticated plant species compared to their wild compared to their wild relatives. relatives.

Genetically Modified (GM) CropsGenetically Modified (GM) CropsMost new genetic engineering techniques initially Most new genetic engineering techniques initially involve single-gene modifications of species, and in involve single-gene modifications of species, and in many cases such modifications are less useful than the many cases such modifications are less useful than the multiple-gene changes that result from traditional multiple-gene changes that result from traditional breeding programs.breeding programs.

MaizeMaize Maize genetically Maize genetically modified to produce modified to produce 

Bt proteinBt protein

Bt protein kills Bt protein kills the the 

corn borer insectcorn borer insect

Biodiversity of Biodiversity of FoodFood

Risks of High-Yielding Crop VarietiesRisks of High-Yielding Crop Varieties

Whereas traditional mixed farming systems produce Whereas traditional mixed farming systems produce modest but reliable yields, planting a single modern crop modest but reliable yields, planting a single modern crop variety over a large area can result in high yields but the variety over a large area can result in high yields but the crop may be extremely vulnerable to pests, disease and crop may be extremely vulnerable to pests, disease and severe weather. The results may be substantial loss of severe weather. The results may be substantial loss of yield (e.g., the 1970 loss of more than 15% of corn crop yield (e.g., the 1970 loss of more than 15% of corn crop to a fungus). to a fungus).

Single crop agriculture has a history of producing Single crop agriculture has a history of producing famines when an organism of opportunity destroys that famines when an organism of opportunity destroys that crop.crop.

Loss of Crop DiversityLoss of Crop Diversity

Problems with Genetic UniformityProblems with Genetic Uniformity

Genetic diversity provides the variation within Genetic diversity provides the variation within species that allows populations to adapt to changes species that allows populations to adapt to changes in climate and other local environmental conditions.in climate and other local environmental conditions.

Without a constant infusion of new hardy genes Without a constant infusion of new hardy genes into our crop species, pests and diseases could into our crop species, pests and diseases could quickly get out of hand. Already more than 400 quickly get out of hand. Already more than 400 species of crop pests have developed resistance to species of crop pests have developed resistance to one or more of the pesticides used to control them.one or more of the pesticides used to control them.

National Plant Germplasm System (NPGS)National Plant Germplasm System (NPGS)

NPGS is a cooperative effort by public (State and NPGS is a cooperative effort by public (State and Federal) and private organizations to preserve the Federal) and private organizations to preserve the genetic diversity of plants.genetic diversity of plants.

The NPGS acquires, preserves and distributes crop The NPGS acquires, preserves and distributes crop germplasm.germplasm.

There is also a National Animal Germplasm Program There is also a National Animal Germplasm Program under development.under development.

Approximately 99% of the world food supply is derived from Approximately 99% of the world food supply is derived from terrestrial ecosystems with the percentage from aquatic terrestrial ecosystems with the percentage from aquatic systems shrinking. systems shrinking.

The availability of arable land at world level is less than 0.27 The availability of arable land at world level is less than 0.27 ha per capita, lower than it has ever been in history, and much ha per capita, lower than it has ever been in history, and much less than the average of 0.7 ha per capita in the United States. less than the average of 0.7 ha per capita in the United States. Note that 0.5 ha per capita has been suggested as the Note that 0.5 ha per capita has been suggested as the minimum requirement for a diverse diet of animal and plant minimum requirement for a diverse diet of animal and plant food productsfood products

Sources of FoodSources of Food

FisheriesFisheries

Basic problem Basic problem with ocean with ocean fisheries is the fisheries is the issue of the issue of the tragedy of the tragedy of the commons. No commons. No single nation single nation may legislate or may legislate or enforce policies.enforce policies.

The World’s Fisheries

Fish Farms (Aquaculture)Fish Farms (Aquaculture)

Are fresh water and marine water facilities.Are fresh water and marine water facilities.

Approximately 1/3 of the shrimp consumed globally are Approximately 1/3 of the shrimp consumed globally are from aquaculture sources.from aquaculture sources.

More than 50% of salmon More than 50% of salmon consumed is raised on fish consumed is raised on fish farms.farms.

Fish Farms (Aquaculture)Fish Farms (Aquaculture)

Farmed fish are frequently fed Farmed fish are frequently fed on meal made from wild-caught on meal made from wild-caught fish. In 2000, Goldburg co-fish. In 2000, Goldburg co-authored a paper revealing that authored a paper revealing that 1.9 kilograms of wild fish were 1.9 kilograms of wild fish were on average required to produce on average required to produce every 1 kg of fish farmed in every 1 kg of fish farmed in

1997.1997.

Farming and the Environment Plowing is

unnatural…

Good news on Erosion

Deforestation – how a tree grows

Forests as a Resource

• Never cut is called a old-growth forest

• Cut and regrown = second-growth forest

• Sustainability comes from cutting slower than the forest regrows.

Where are the forests now?

Fossil Fuels I Fossil Fuels I Chapt 17-20Chapt 17-20

Energy Basics

• Types of energy – potential and kinetic

What is efficient?

Should the Should the Gasoline Tax Gasoline Tax Be Raised?Be Raised?

Pros?Pros?

Cons?Cons?

Country Price PerLiterIn U.S. $

Price PerU.S. GallonIn U.S. $

Canada             

$0.489 $1.858

France             

$1.110 $4.191

Germany             

$1.179 $4.460

Italy             

$1.135 $4.294

Country Price PerLiterIn U.S. $

Price PerU.S. GallonIn U.S. $

Japan             

$0.885 $3.348

Spain

                         

$0.880 $3.329

United Kingdom

            

$1.286 $4.865

United States

            

$0.384 $1.453

Selected World Gasoline PricesSelected World Gasoline PricesAverage, January, 2003Average, January, 2003

2006 and 2010

Date Belgium France Germany Italy Netherlands U.K. U.S.3/20/2006 5.62 5.69 5.86 5.81 6.44 5.99 2.70

Date Belgium France Germany Italy Netherlands U.K. U.S.5/1/2010 7.38 6.89 7.19 6.97 7.91 7.00 2.68

Breakdown on Breakdown on Gasoline CostsGasoline Costs

USA Regional Differences USA Regional Differences Gasoline Prices 2002Gasoline Prices 2002

Regional Differences 2004

                                   

                                                             

What are Fossil Fuels?What are Fossil Fuels?

All fossil fuels are forms of All fossil fuels are forms of stored solar energystored solar energy that are created from incomplete biological that are created from incomplete biological decomposition.decomposition.

Fossil Fossil non-renewablenon-renewable fuels include: fuels include:CoalCoalOilOilNatural gasNatural gas

Sources of Energy Used by HumansSources of Energy Used by Humans

Fossil Fuels Predominant Energy SourceFossil Fuels Predominant Energy Source

Fossil fuels Fossil fuels ~ 85%~ 85%Nuclear Nuclear ~ 6% ~ 6% Hydroelectric Hydroelectric ~ 4%~ 4%Biomass fuelsBiomass fuels < 5% < 5% AlternativesAlternatives ~1% ~1%

20% of the World’s Population 20% of the World’s Population Consumes 68% of the World’s Energy.Consumes 68% of the World’s Energy.

What is the difference between US/Canada and Switzerland/Japan/Denmark in energy use?

Where Energy Goes in the U.S.A.Where Energy Goes in the U.S.A.

IndustryIndustry ~ 42%~ 42%Making metals; chemical industry (plastics, Making metals; chemical industry (plastics, fertilizers)fertilizers)

Residential/commercial ~ 33%Residential/commercial ~ 33% Heating, air conditioning, lighting, and hot Heating, air conditioning, lighting, and hot waterwater

Transportation ~ 25% Transportation ~ 25% Passenger travel, hauling by semi (Passenger travel, hauling by semi (Trains, Trains, barges, ships and pipelines use 12% of fuel, barges, ships and pipelines use 12% of fuel, yet haul 75% of freight.yet haul 75% of freight.

Where Energy Goes in the U.S.A.Where Energy Goes in the U.S.A.

OilOil and Gas wa and Gas was Formed by Partial s Formed by Partial Decomposition of Aquatic OrganismsDecomposition of Aquatic Organisms

OILOILLocationLocation - usually in porous and coarse-grained - usually in porous and coarse-grained stone such as stone such as sandstone and limestone.sandstone and limestone.

Requires a Requires a traptrap - rock, like shale, that impedes the - rock, like shale, that impedes the hydrocarbons in anticlines (arch-shaped folds). hydrocarbons in anticlines (arch-shaped folds).

Who’s fault is it?

OilOilExtraction:Extraction:

Primary RecoveryPrimary Recovery (~25%)(~25%) - oil is under - oil is under pressure, so pumping pressure, so pumping oil is a way to control oil is a way to control the extraction of oil.the extraction of oil.

Secondary RecoverySecondary Recovery (>50%)(>50%) - injecting - injecting steam, water, or steam, water, or chemicals (carbon chemicals (carbon dioxide, nitrogen) dioxide, nitrogen)

World Gas and World Gas and Crude Oil Crude Oil ReservesReserves

Crude OilCrude OilNatural GasNatural Gas

Known Oil ReservesKnown Oil Reserves

60% of proven recoverable oil reserves in 60% of proven recoverable oil reserves in the the Mid-EastMid-East. .

ProvenProven reserves of oil = 1 trillion barrels reserves of oil = 1 trillion barrels

At 22 billion barrels a year (present rate), At 22 billion barrels a year (present rate), this isthis is 45 years worth of oil.45 years worth of oil.

Uses of OilUses of Oil

Environmental Effects of Oil and Gas UseEnvironmental Effects of Oil and Gas Use

Carbon Dioxide ReleaseCarbon Dioxide Release

Water ContaminationWater ContaminationPollution of marine waters from leaks or Pollution of marine waters from leaks or spills.spills.

Wastewater used in secondary recovery.Wastewater used in secondary recovery.

Pollution of surface waters and groundwater Pollution of surface waters and groundwater from runoff and leaking from broken pipes from runoff and leaking from broken pipes and storage tanks.and storage tanks.

Spills Spills Gulf war = 250 million gallonsGulf war = 250 million gallons

Exxon Valdez = 11 million gallonsExxon Valdez = 11 million gallons

Environmental Effects of Oil and Gas UseEnvironmental Effects of Oil and Gas Use

Soil ContaminationSoil ContaminationFrom wells, pipelines, storage tanks, and From wells, pipelines, storage tanks, and roadsroads

Release of drilling mudRelease of drilling mud

Smoke tornado

ANWR = 200 day supply ANWR = 200 day supply of oil?of oil?

What are What are the Costs the Costs and and Benefits of Benefits of Exploring Exploring the ANWR the ANWR for Oil?for Oil?

Natural GasNatural Gas

Formation similar to oil, from partially Formation similar to oil, from partially decomposed aquatic organisms subjected to heat decomposed aquatic organisms subjected to heat and pressure.and pressure.

In contrast to oil which consists of a mixture of In contrast to oil which consists of a mixture of often hundreds of hydrocarbons, natural gas is often hundreds of hydrocarbons, natural gas is composed primarily of one hydrocarbon – composed primarily of one hydrocarbon – methane.methane.

Natural gas is more expense to transport than oil, Natural gas is more expense to transport than oil, and it is often burned off at an oil well as waste.and it is often burned off at an oil well as waste.

Advantages of Natural Gas Advantages of Natural Gas

Compared to oil products, natural gas produces about 80-90% fewer emission when used in vehicles.

Natural gas can be used for both heating and cooling systems.

Natural gas is more plentiful than oil.

Peak Oil

CoalCoal

Coal was formed by the partial decay of plants and Coal was formed by the partial decay of plants and animals. Under heat and pressure from burial by animals. Under heat and pressure from burial by later material, the partially decomposed plant later material, the partially decomposed plant material became the carbon-rich rock we call coal.material became the carbon-rich rock we call coal.

Coal may be classified as lignite, bituminous, or Coal may be classified as lignite, bituminous, or anthracite according to its hardness. Anthracite, anthracite according to its hardness. Anthracite, the hardest, was formed under the highest the hardest, was formed under the highest temperatures and produces the fewest pollutants temperatures and produces the fewest pollutants when burned.when burned.

Carboniferous forests from which coal was formed

Coal Coal CompositionComposition

Formation - 300 million years Formation - 300 million years agoago

Kinds:Kinds::AnthraciteAnthracite - hard coal, shiny, - hard coal, shiny,

blue/black coal. Highest blue/black coal. Highest heat producing capacity of heat producing capacity of the coals. Lowest volatiles.the coals. Lowest volatiles.

BituminousBituminous - called soft coal, called soft coal, but is hard, bright black but is hard, bright black coal - usually high in sulfur coal - usually high in sulfur volatiles.volatiles.

Lignite Lignite - soft, moist coal - soft, moist coal which produces little heat which produces little heat compared to other coalscompared to other coals.

How Coal is Made

Coal Coal ExtractionExtraction

Extraction - Strip minesExtraction - Strip mines

1. Bulldozers and scrapers remove the vegetation and 1. Bulldozers and scrapers remove the vegetation and topsoil from an area.topsoil from an area.

2. Soil is stockpiled for reuse.2. Soil is stockpiled for reuse.3. Overburden (rock over the coal) is removed.3. Overburden (rock over the coal) is removed.4. Coal beds are drilled and blasted and loaded.4. Coal beds are drilled and blasted and loaded.5. The cut is filled and topsoil is replaced.5. The cut is filled and topsoil is replaced.

Surface Mining Control and Reclamation ActSurface Mining Control and Reclamation Act 19771977Prior to this, land did not have to be re-established.Prior to this, land did not have to be re-established.

World coal deposits are vast (10x greater than oil), World coal deposits are vast (10x greater than oil), and reserves could last for more than 200 yearsand reserves could last for more than 200 years

Environmental Effects of Coal MiningEnvironmental Effects of Coal Mining

Carbon dioxide releaseCarbon dioxide release

Sulfur dioxide and nitrogen oxide release - leads Sulfur dioxide and nitrogen oxide release - leads to acid precipitationto acid precipitation

Mine acid drainage - acidifies streams; toxic Mine acid drainage - acidifies streams; toxic metals introduced into streamsmetals introduced into streams

Release of radioactivity and toxic metalsRelease of radioactivity and toxic metals

Environmental Effects of Coal MiningEnvironmental Effects of Coal Mining

Land disturbance Land disturbance

Other human risks:Other human risks:

Black lung diseaseBlack lung disease

Cave-insCave-ins

Coal firesCoal fires

Acid Deposition ProblemsAcid Deposition Problems

Ways to Alleviate PollutionWays to Alleviate Pollution

Chemical or physical cleaning of coal prior to Chemical or physical cleaning of coal prior to combustion.combustion.

Boiler designs that require a lower temperature of Boiler designs that require a lower temperature of combustion, reducing emissions of nitrogen oxides.combustion, reducing emissions of nitrogen oxides.

Fluidized Bed Combustion -Fluidized Bed Combustion - Injection of material rich Injection of material rich in calcium carbonate while burning. Reacts with sulfur in calcium carbonate while burning. Reacts with sulfur dioxide, producing a calcium sulfate sludge.dioxide, producing a calcium sulfate sludge.

Scrubbing/Filter/Precipitator following burningScrubbing/Filter/Precipitator following burning.

Fluidized Bed Combustion - Limestone captures sulfur and nitrogen impurities in slag, decreasing pollutants in the air.

ScrubberScrubber

ElectrostaticElectrostaticPrecipitator Precipitator

Fabric FilterFabric Filter

Reserves at Reserves at Present Rate of Present Rate of Consumption:Consumption:

Oil: 45 yearsOil: 45 years

Coal: 200 yearsCoal: 200 years

But will energy But will energy consumption level out?consumption level out?

Fossil Fuels IIFossil Fuels II

Oil, Coal,

Natural Gas are all solar energy and…

SynfuelsSynfuels

Gas or liquid fuels from hydrocarbons Gas or liquid fuels from hydrocarbons locked locked in rock.in rock.

Oil ShaleOil ShaleTar SandsTar SandsMethane HydrateMethane Hydrate

Tar SandTar Sand

Molecules of Molecules of natural gas trapped natural gas trapped inside crystals of inside crystals of ice.ice. Gas stores Gas stores compactly inside compactly inside ice, and estimates ice, and estimates of gas hydrate of gas hydrate beneath permafrost beneath permafrost alone ranges from alone ranges from 5,000 to 12 million 5,000 to 12 million trillion cubic feet trillion cubic feet (tcf). (tcf).

Gas Hydrates (Methane Gas Hydrates (Methane Hydrates)Hydrates)

Gas Hydrates (Methane Hydrates)Gas Hydrates (Methane Hydrates)

Gas hydrate resource could exceed 60 Gas hydrate resource could exceed 60 million trillion cubic feet of gas - almost million trillion cubic feet of gas - almost 5,000 times the conventional natural gas 5,000 times the conventional natural gas resource. resource.

That number is also That number is also 730,000 times annual 730,000 times annual gas consumptiongas consumption for the globe - which for the globe - which equaled 82 tcf in 1998. equaled 82 tcf in 1998.

Gas Hydrates – Current LimitationsGas Hydrates – Current LimitationsGas hydrates are in difficult locations to drill - Gas hydrates are in difficult locations to drill - either under Arctic permafrost or below at least either under Arctic permafrost or below at least 500 meters of water. 500 meters of water.

Nobody knows how to extract hydrates safely. Nobody knows how to extract hydrates safely.

Deposits cannot be exploited economically with Deposits cannot be exploited economically with existing technology. existing technology.

Could actually accelerate global warming. Could actually accelerate global warming.

Gas Hydrates – Current LimitationsGas Hydrates – Current LimitationsGlobal warming Global warming and ocean rise and ocean rise could create could create dramatic dramatic atmospheric atmospheric changes. Positive changes. Positive feedback since feedback since CHCH44 is 10 times is 10 times

more effective that more effective that COCO2 2 in producing in producing

warming.warming.

Alternatives to Fossil EnergyAlternatives to Fossil Energy

Biomass Biomass - usually waste wood scraps.- usually waste wood scraps.

SolarSolar - total energy receive each year from the sun - total energy receive each year from the sun is ~ 35,000 times the total energy used by man.is ~ 35,000 times the total energy used by man.

Wind Wind - highly dependent on weather and locations.- highly dependent on weather and locations.

Geothermal Geothermal - minor except where hot spots.- minor except where hot spots.

Tides Tides - motion of tides used to fill reservoirs.- motion of tides used to fill reservoirs.

Hydroelectric Hydroelectric -- large initial costs, but low large initial costs, but low maintenance costs and cheap energy source.maintenance costs and cheap energy source.

BiomassBiomass

Renewable Renewable

Saves landfillSaves landfill

80% 80% currently currently from paper from paper and pulp and pulp industriesindustries

Solar Solar EnergyEnergy

Enough electric power for the entire country could be generated by covering about 9% of Nevada (a plot of land 100 miles on a side) with parabolic trough systems.

WindWindGood wind areas, Good wind areas, which cover 6% which cover 6% of the contiguous of the contiguous U.S. land area, U.S. land area, could supply more could supply more than one and a than one and a half times the half times the 1993 electricity 1993 electricity consumption of consumption of the entire United the entire United States.States.

Clusters of wind Clusters of wind turbines are called turbines are called Wind Farms.Wind Farms.

U.S. geothermal resourcesU.S. geothermal resources alone are estimated alone are estimated as able to produce a as able to produce a 750,000 year supply of 750,000 year supply of energy for the entire nationenergy for the entire nation at current rates of at current rates of consumption. consumption.

The geothermal energy potential in the The geothermal energy potential in the uppermost 6 miles of the Earth's crust uppermost 6 miles of the Earth's crust amounts to 50,000 times the energy of all oil amounts to 50,000 times the energy of all oil and gas resources in the world.and gas resources in the world.

GeothermalGeothermal

Geothermal MapGeothermal Map

Geothermal Power

HydroelectricHydroelectricTo have a viable hydropower resource, you must To have a viable hydropower resource, you must have both a large volume of water and a significant have both a large volume of water and a significant change in elevation.change in elevation.

Hydropower is the least expensive source of Hydropower is the least expensive source of electricity in the United Stateselectricity in the United States, with typical , with typical efficiencies of 85%-92% during production. efficiencies of 85%-92% during production.

For every kilowatt-hour (kWh) of electricity For every kilowatt-hour (kWh) of electricity produced by hydropower, only 0.6 cents is needed to produced by hydropower, only 0.6 cents is needed to pay for operating and maintaining the plant. pay for operating and maintaining the plant. Comparable costs are 2.2 cents/kWh at nuclear plants Comparable costs are 2.2 cents/kWh at nuclear plants and 2.1 cents/kWh at coal plants.and 2.1 cents/kWh at coal plants.

Nuclear Energy Nuclear Energy Chapter 11Chapter 11

Fossil Fuels Projections

Basic TerminologyBasic Terminology

CombustionCombustion - the breaking of carbon-carbon bonds, - the breaking of carbon-carbon bonds, causing the release of energy. causing the release of energy. Elements do not change Elements do not change form,form, it is it is just the rearrangement of electrons.just the rearrangement of electrons.

FissionFission - - the the splitting of atomssplitting of atoms of an element into two of an element into two smaller atoms.smaller atoms.

FusionFusion - - the the merges atomsmerges atoms of an element into fewer of an element into fewer larger atoms. Is the power source of the sun and stars.larger atoms. Is the power source of the sun and stars.

IsotopesIsotopes - differing forms (# neutrons) of the same - differing forms (# neutrons) of the same element.element.

RadioactiveRadioactive - isotopes which are unstable; they emit - isotopes which are unstable; they emit high levels of energy (radiation) and form new elementshigh levels of energy (radiation) and form new elements

Energy Consumption by FuelEnergy Consumption by Fuel

Fusion ReactionsFusion Reactions

Fusing one kilogram of Fusing one kilogram of hydrogen into helium hydrogen into helium releases 650 trillion releases 650 trillion Joules of energy. Joules of energy.

This is over 4 million This is over 4 million times the energy times the energy released by burning the released by burning the same amount of same amount of hydrogen. hydrogen.

Fusion ReactionsFusion Reactions

Overcoming the electric repulsion between hydrogen Overcoming the electric repulsion between hydrogen nuclei requires high random velocities nuclei requires high random velocities (T > 10,000,000 (T > 10,000,000 degrees Kelvin).degrees Kelvin). Even at these high temperatures, fusion Even at these high temperatures, fusion is inefficient; only a minuscule fraction of collisions is inefficient; only a minuscule fraction of collisions between nuclei result in fusion. To compensate for the between nuclei result in fusion. To compensate for the low efficiency of fusion, you need high densities of low efficiency of fusion, you need high densities of hydrogen.hydrogen.

These hot, dense conditions occur in the centers of stars.These hot, dense conditions occur in the centers of stars.

Fusion ReactionsFusion Reactions

If the Sun were initially madeIf the Sun were initially made entirely of hydrogen, fusing that entirely of hydrogen, fusing that hydrogen into helium would hydrogen into helium would provide enough energy to provide enough energy to power the Sun for 100 billion power the Sun for 100 billion years (a time comfortably long years (a time comfortably long compared to the Sun's current compared to the Sun's current age of approximately 5 billion age of approximately 5 billion

years).years).

Fission ReactionsFission Reactions

Conventional Nuclear FissionU-235U-235 is the isotope used by conventional nuclear reactors. is the isotope used by conventional nuclear reactors. It is found in ores in a concentration of It is found in ores in a concentration of 0.7%.0.7%.

U235 is refined, or U235 is refined, or enrichedenriched, to a concentration of , to a concentration of 3%3% for use.for use.

Pellets are put into Pellets are put into fuel rodsfuel rods (hollow tubes), and fuel rods (hollow tubes), and fuel rods are grouped into are grouped into fuel assembliesfuel assemblies..

Above a fuel assembly areAbove a fuel assembly are control rods control rods made of a special made of a special alloy which absorbs neutrons.alloy which absorbs neutrons.

Pressurized water nuclear reactorPressurized water nuclear reactor

primary water circuit - in containment structure; HOTsecondary water circuit - heated by primary; turns turbinetertiary water circuit - the heat sink, condenses water.

HOT (radioactive) water outside of the containment HOT (radioactive) water outside of the containment structure. structure.

Meltdown - when nuclear fuel is so hot it forms a molten Meltdown - when nuclear fuel is so hot it forms a molten mass and breaches the containment structuremass and breaches the containment structure.

Percent of Percent of Electricity Electricity

From Nuclear From Nuclear ReactorsReactors

Percent of Electricity From Nuclear Percent of Electricity From Nuclear ReactorsReactors

USA Nuclear Power

World Nuclear Power

European Nuclear Power

Sources of Human Exposure to RadiationSources of Human Exposure to Radiation

Health Risks of RadioactivityHealth Risks of Radioactivity

Problems Problems Associated Associated with with Nuclear Nuclear PowerPower

Safety in nuclear Safety in nuclear power plants -power plants -

Three Mile Island Three Mile Island andand

ChernobylChernobyl

Chernobyl Chernobyl April 1986April 1986

31 died immediately31 died immediately

>350 died during >350 died during clean-upclean-up

>24,000 received >24,000 received serious radiation serious radiation exposuresexposures

Red Dot = Thermal Signature of Fire

Sandboxes being replaced in Germany

The next slide contains images that may be disturbing to some

individuals.

Please look away if you may be bothered by images of genetically

mutated children and animals

Genetic Mutations Nearby

This child was adopted by a British couple and, after many surgeries, is leading a relatively normal life (update April 2006).

Three Mile IslandThree Mile Island

Three Mile IslandThree Mile Island

Three Mile Island

In the U.S.A., nuclear reactors were being phased out In the U.S.A., nuclear reactors were being phased out due to: Rapidly increasing construction costs; due to: Rapidly increasing construction costs; decreasing costs of alternative energy sources; public decreasing costs of alternative energy sources; public opposition.opposition.

The average time to The average time to construct a new plant construct a new plant was 6.3 years in the was 6.3 years in the U.S. in 1971. U.S. in 1971.

In 1991 the time was: In 1991 the time was: 14 years in the U.S.A. 14 years in the U.S.A. 7 years in Japan7 years in Japan 5 years in France 5 years in France

In the U.S. no plant ordered between In the U.S. no plant ordered between 1974 and 1978 is still under 1974 and 1978 is still under construction. There have been no new construction. There have been no new USA orders since 1978.USA orders since 1978.

Problems Associated with Nuclear PowerProblems Associated with Nuclear Power

Radioactive waste disposal - Radioactive waste disposal - Mines and mills produce Mines and mills produce radioactive wastes and pollute the environment.radioactive wastes and pollute the environment.

Problems Associated with Nuclear Problems Associated with Nuclear PowerPower

TerrorismTerrorism

Nuclear wastesNuclear wastes - long half life, so long term disposal long half life, so long term disposal must be for 10’s of thousands of years. Enrichment must be for 10’s of thousands of years. Enrichment produces radioactive wastes, and spent fuel has to be produces radioactive wastes, and spent fuel has to be disposed.disposed.

Economic Costs Economic Costs -- decommissioning nuclear power decommissioning nuclear power plants and deconstruction can cost 10X construction. plants and deconstruction can cost 10X construction. Also, Also, costs for storage (see above)

Horrible disposal practices by the Soviet Union.

High Level Waste High Level Waste Repository Planned Repository Planned on Desert Ridge on Desert Ridge near Yucca near Yucca Mountain, Nevada.Mountain, Nevada.

Benefits?Benefits?

Risks/Costs?Risks/Costs?

Renewable Sources of Energy Renewable Sources of Energy Chapter 12Chapter 12

Renewable EnergyRenewable Energy

Renewable energy is any energy sources which is not used up; Renewable energy is any energy sources which is not used up; provides alternatives to fossil fuels and nuclear energy. provides alternatives to fossil fuels and nuclear energy.

Most energy directly from the sun (exceptions = nuclear, Most energy directly from the sun (exceptions = nuclear, geothermal and tidal).geothermal and tidal).

Currently the main Currently the main constraint from using constraint from using renewable energy sources renewable energy sources isis EconomicEconomic. .

As more non-renewable As more non-renewable sources are consumed, sources are consumed, renewable sources become renewable sources become more competitive. more competitive.

Renewable Renewable Sources that Sources that are Currently are Currently Competitive Competitive with Coal, with Coal, Oil, NuclearOil, Nuclear

HydroelectricHydroelectricWindWindGeothermalGeothermalSolar Thermal?Solar Thermal?

Direct Solar Energy for Heating Direct Solar Energy for Heating Buildings and WaterBuildings and Water

Passive Solar Heating - No Moving Parts.Passive Solar Heating - No Moving Parts.

Glass Glass Greenhouse effect - transparent to light; captures heat Greenhouse effect - transparent to light; captures heat

Sun - lower in Sun - lower in the sky in the the sky in the winter.winter.

South-facing South-facing windows windows (winter vs. (winter vs. summer summer differences)differences)

Passive Solar HeatingPassive Solar Heating

Active Solar HeatingActive Solar HeatingSolar panels of black metal with insulated box. Solar panels of black metal with insulated box. Water pumped to a building or a storage tankWater pumped to a building or a storage tank

Especially Especially effective for effective for heating water heating water (8% of the (8% of the energy energy consumed in consumed in U.S. is for U.S. is for heating water).heating water).

Active Heating and Active Heating and CoolingCooling

The upper 10 The upper 10 feet of the feet of the Earth maintains Earth maintains a nearly a nearly constant constant temperature temperature between 50° between 50° and 60°F (10°–and 60°F (10°–16°C).16°C).

Heat pump - Heat pump - uses the ground uses the ground to cool the air to cool the air in summer and in summer and warm the air in warm the air in winter.winter.

Earth-sheltered structures – since the earth stays a Earth-sheltered structures – since the earth stays a relatively constant temperature, less heating in winter relatively constant temperature, less heating in winter and less cooling in summer.and less cooling in summer.

Direct Solar Energy for HeatingDirect Solar Energy for HeatingBenefit - Benefit - nonpolluting; fuel cost savings.nonpolluting; fuel cost savings.Limitation - sLimitation - start-up costs high (Cost/benefit ratio better for tart-up costs high (Cost/benefit ratio better for

long-term homeowners.)long-term homeowners.)

Solar Generation of Electricity:Solar Generation of Electricity:

Solar Thermal Electric GeneratorsSolar Thermal Electric Generators

Solar Power TowersSolar Power Towers

Photovoltaic Solar CellsPhotovoltaic Solar Cells

Solar HydrogenSolar Hydrogen Standard process to generate electricity

Solar Thermal Electric GeneratorsSolar Thermal Electric Generators

1. Mirrors focus sunlight2. Oil-filled pipes heated3. Oil heats water to steam4. Steam turns a turbine - electricity

Solar Thermal Electric GeneratorsSolar Thermal Electric GeneratorsLimitations:Limitations: Backup needed for when solar not available. Backup needed for when solar not available. Close to cost of oil/coal, but no incentives for investors.Close to cost of oil/coal, but no incentives for investors. Large tracts of land needed.Large tracts of land needed.

Solar Energy CostsSolar Energy Costs

Troughs are the least expensive, most reliable solar Troughs are the least expensive, most reliable solar technology for near-term, utility-scale applications.technology for near-term, utility-scale applications.

High optical efficiency, low thermal losses, and high engine High optical efficiency, low thermal losses, and high engine conversion efficiencies make dish/engine systems the most conversion efficiencies make dish/engine systems the most efficient of all solar technologies.efficient of all solar technologies.

Solar Dish/EngineSolar Dish/EngineA dish/engine system is a stand-alone unit composed A dish/engine system is a stand-alone unit composed primarily of a collector, a receiver, and an engine. The primarily of a collector, a receiver, and an engine. The sun's energy is collected and concentrated by a dish-sun's energy is collected and concentrated by a dish-shaped surface onto an receiver that absorbs the energy shaped surface onto an receiver that absorbs the energy and transfers it to the engine's working fluid.and transfers it to the engine's working fluid.

Solar Dish/EngineSolar Dish/Engine

The mechanical power is converted to electrical power The mechanical power is converted to electrical power by an electric generator or alternator.by an electric generator or alternator.

The ideal concentrator shape is parabolic, created either The ideal concentrator shape is parabolic, created either by a single reflective surface or multiple reflectors, or by a single reflective surface or multiple reflectors, or facets.facets.

Solar Power TowersSolar Power Towers1.1. Mirrors focus sunlight onto receiverMirrors focus sunlight onto receiver2. 2. Receiver heats water to steamReceiver heats water to steam3. 3. Steam turns a turbine - electricitySteam turns a turbine - electricity

Limitations:Limitations: Construction costs high. Construction costs high. Large tracts of land neededLarge tracts of land needed

Solar Power TowersSolar Power Towers

With thermal storage, power towers can operate at an annual With thermal storage, power towers can operate at an annual capacity factor of 65%, which means they can potentially capacity factor of 65%, which means they can potentially operate for 65% of the year without the need for a back-up operate for 65% of the year without the need for a back-up fuel source.fuel source.

Photovoltaic Solar CellsPhotovoltaic Solar Cells

1. 1. Semiconductor absorbs lightSemiconductor absorbs light2. 2. Light liberates electronsLight liberates electrons3. 3. Flow of electricityFlow of electricity

Unique Benefits:Unique Benefits: Do not Do not need powerlines.need powerlines.

Limitation:Limitation: Not cost-effective now. Not cost-effective now. But, decreasing cost and But, decreasing cost and increasing efficiencyincreasing efficiency

Solar shinglesSolar shingles - - thin-film solar cells are much cheaper to thin-film solar cells are much cheaper to make and can be used in ‘free space’ like roofs.make and can be used in ‘free space’ like roofs.

How Much Energy Can Solar Cells Produce?How Much Energy Can Solar Cells Produce?

A typical PV or solar cell is a square that measures about A typical PV or solar cell is a square that measures about 4 inches (10 centimeters) on a side. A cell can produce 4 inches (10 centimeters) on a side. A cell can produce about 1 watt of power - more than enough to power a about 1 watt of power - more than enough to power a watch, but not enough to run a radio.watch, but not enough to run a radio.

When more power is needed, some 40 PV cells can be When more power is needed, some 40 PV cells can be connected together to form a "module." A typical module connected together to form a "module." A typical module is powerful enough to light a small light bulb. For larger is powerful enough to light a small light bulb. For larger power needs, about 10 such modules are mounted in PV power needs, about 10 such modules are mounted in PV "arrays," which can measure up to several meters on a "arrays," which can measure up to several meters on a side. side.

Photovoltaic ModulesPhotovoltaic Modules

In 1994, more than 75% of the PV modules produced In 1994, more than 75% of the PV modules produced in the United States were exported, mostly to in the United States were exported, mostly to developing countries where 2 billion people still live developing countries where 2 billion people still live without electricity.without electricity.

PV modules covering 0.3% of the land in the United PV modules covering 0.3% of the land in the United States could provide all the U.S. electricity States could provide all the U.S. electricity consumption. This amount of land equals one fourth consumption. This amount of land equals one fourth of the land occupied by roadways.of the land occupied by roadways.

Solar HydrogenSolar HydrogenUse electricity from photovoltaic cells to split HUse electricity from photovoltaic cells to split H220 into H0 into H22 and and

OO22. H. H22 is clean burning and can be stored. is clean burning and can be stored.

Limitations:Limitations: same as photovoltaic + only 8% from photovoltaic same as photovoltaic + only 8% from photovoltaic cell captured.cell captured.

Wind EnergyWind Energy

Wind turbines are available in a variety of sizes, and therefore power ratings.

The largest machine, in Hawaii, has propellers that span more than the length of a football field and stands 20 building stories high, and produces enough electricity to power 1400 homes.

A small home-sized wind machine has rotors between 8 and 25 feet in diameter and stands upwards of 30 feet and can supply the power needs of an all-electric home or small business.

Wind EnergyWind EnergyWind power uses relatively little Wind power uses relatively little waterwater in the production in the production of energy, and important consideration where water is of energy, and important consideration where water is scarce. scarce. Water ConsumptionWater Consumption

Technology gallons/kWh liters/kWh

Nuclear 0.62 2.30

Coal 0.49 1.90

Oil 0.43 1.60

Photovoltaic 0.030 0.110

Wind 0.001 0.004

Wind EnergyWind Energy

Most cost-competitive of all Most cost-competitive of all forms of “solar energy.” forms of “solar energy.”

pumping waterpumping waterirrigating fieldsirrigating fieldsgrinding graingrinding grainturn turbines to generate turn turbines to generate

electricityelectricity

Buffalo Ridge,Buffalo Ridge, Minnesota Minnesota Construction cost similar to coal-Construction cost similar to coal-fired power plant. fired power plant.

$1 million per turbine$1 million per turbine$500 million total$500 million total

Wind TurbinesWind Turbines

Benefits:Benefits:Wind energy is free. Wind energy is free. Cost is competitive.Cost is competitive.Land less than area for mining.Land less than area for mining.Land can be grazed.Land can be grazed.

Environmental Problems:Environmental Problems:Dangerous to birds: avoid migration routes.Dangerous to birds: avoid migration routes.Soaring birds at some risk.Soaring birds at some risk.

Good Places to Place Them

HydropowerHydropower

Hydropower (also called hydroelectric power) facilities in Hydropower (also called hydroelectric power) facilities in the United States can generate enough power to supply 28 the United States can generate enough power to supply 28 million households with electricity, the equivalent of nearly million households with electricity, the equivalent of nearly 500 million barrels of oil. 500 million barrels of oil.

Types of hydropower:Types of hydropower:ImpoundmentImpoundmentDiversionDiversionPumped storagePumped storage

HydropowerHydropower

Over one-halfOver one-half (52 percent) of the total U.S. hydroelectric (52 percent) of the total U.S. hydroelectric capacity for electricity generation is concentrated in three capacity for electricity generation is concentrated in three States (States (Washington, California and OregonWashington, California and Oregon) with ) with approximately 27 percent in Washington, the location of the approximately 27 percent in Washington, the location of the Nation’s largest hydroelectric facility – the Grand Coulee Nation’s largest hydroelectric facility – the Grand Coulee Dam. Dam.

Limitations of hydropower:Limitations of hydropower:

Fish passage - fish laddersFish passage - fish laddersWater quality - can reduce dissolved oxygenWater quality - can reduce dissolved oxygenWater flow - maintenance of riparian habitatsWater flow - maintenance of riparian habitatsCultural and scenic preservationCultural and scenic preservation

HydropowerHydropower

Based on the water cycle. Based on the water cycle.

1. Potential energy of water 1. Potential energy of water held back by a dam held back by a dam

2. Converted to electricity: 2. Converted to electricity: water turns a turbine as water turns a turbine as it falls over a spillwayit falls over a spillway

HydropowerHydropower

Electricity from dams supplies Electricity from dams supplies 25% of world's demand. 25% of world's demand. Norway depends on Norway depends on hydropower for over 90% of its hydropower for over 90% of its electricity.electricity.

Environmental Problems:Environmental Problems:Flooding useful landsFlooding useful landsDestruction of ecosystemsDestruction of ecosystemsIncrease water-borne diseasesIncrease water-borne diseases

+ high start-up costs+ high start-up costs+ siltation+ siltation

Hydroelectric Plants

Low-head HydropowerLow-head Hydropower

High High efficiency efficiency turbinesturbines Operate run-Operate run-of-the-river of-the-river flowflow

No No impoundment impoundment reservoirs.reservoirs.

Biomass Energy - Solar Biomass Energy - Solar Energy Converted by Energy Converted by

PhotosynthesisPhotosynthesis. Cooking and Heating:Cooking and Heating:

WoodWoodCharcoalCharcoalPeatPeatAnimal DungAnimal Dung

BiomassBiomass

Today, Today, wood is still our largest biomass energy resourcewood is still our largest biomass energy resource. .

Many other sources of biomass can now be used, Many other sources of biomass can now be used, including plants, residues from agriculture or forestry, including plants, residues from agriculture or forestry, and the organic component of municipal and industrial and the organic component of municipal and industrial wastes. wastes.

Even the fumes from landfills can be used as a biomass Even the fumes from landfills can be used as a biomass energy source. energy source.

Today, we depend on biomass to provide Today, we depend on biomass to provide about 3 to 4 about 3 to 4 percent of our energy in the United Statespercent of our energy in the United States. .

BiomassBiomass

Unlike other renewable energy sources, biomass can be Unlike other renewable energy sources, biomass can be converted directly into liquid fuels (biofuels) for our converted directly into liquid fuels (biofuels) for our transportation needs (cars, trucks, buses, airplanes, and transportation needs (cars, trucks, buses, airplanes, and trains). trains).

The two most common types of The two most common types of biofuels are biofuels are ethanolethanol and and biodieselbiodiesel. .

Hydrogen from Hooch!!Hydrogen from Hooch!!

Can convert 103-proof ethanol with 95% efficiency to Can convert 103-proof ethanol with 95% efficiency to hydrogen gas. Rhodium catalyst, water, and oxygen hydrogen gas. Rhodium catalyst, water, and oxygen required. 700required. 700°C is self-sustaining.°C is self-sustaining.

Advantages – convert locally Advantages – convert locally and ethanol easy to transport; and ethanol easy to transport; small, simple equipment small, simple equipment requiredrequired

Disadvantages – generates large Disadvantages – generates large amount of carbon monoxide; amount of carbon monoxide; rhodium catalyst very rhodium catalyst very expensive; not enough EtOHexpensive; not enough EtOH

BiomassBiomass

Products we can make from fossil fuels, we can make Products we can make from fossil fuels, we can make using biomass. These bioproducts, or biobased products, using biomass. These bioproducts, or biobased products, are not only made from renewable sources, they also are not only made from renewable sources, they also often require less energy to produce than petroleum-often require less energy to produce than petroleum-based products. based products.

Researchers have discovered that the process for making Researchers have discovered that the process for making biofuels - releasing the sugars that make up starch and biofuels - releasing the sugars that make up starch and cellulose in plants - cellulose in plants - also can be used to make antifreeze, also can be used to make antifreeze, plastics, glues, artificial sweeteners, and gel for plastics, glues, artificial sweeteners, and gel for toothpaste.toothpaste.

Biomass Energy – Wood and CharcoalBiomass Energy – Wood and Charcoal• Cost: 25% of income can be spent on fuel woodCost: 25% of income can be spent on fuel wood• 2 billion people depend upon fuel wood2 billion people depend upon fuel wood• Half of the wood in the world is harvested for fuelHalf of the wood in the world is harvested for fuel

Dung Compared to MethaneDung Compared to Methane

Burning dung: No fertilizer put back on soils. (800 million tons of dung per year in India)

Burning methane: (1) provides more heat than burning dung, (2) digester sterilizes the dung, (3) provides fertilizer.

Saving!

Conservation and EfficiencyConservation and Efficiency

Fluorescent bulbs -Fluorescent bulbs - use 25% of the energy of incandescent use 25% of the energy of incandescent bulbs. (15-watt = 60-watt).bulbs. (15-watt = 60-watt).

Cost is 10 times as much, but over lifetime, save $30/bulbCost is 10 times as much, but over lifetime, save $30/bulb

Conservation and EfficiencyConservation and EfficiencyNew hybrid automobile enginesNew hybrid automobile engines - Engine recharges - Engine recharges battery when slowing down and braking. Uses gas battery when slowing down and braking. Uses gas when accelerating.when accelerating.

Toyota PriusToyota Prius gets 50 - 60 mpg. gets 50 - 60 mpg. Ford Escape SUVFord Escape SUV in 2004 that gets 45 mpg/city. in 2004 that gets 45 mpg/city.

Conservation and EfficiencyConservation and Efficiency

NegawattsNegawatts: Conservation projects = fewer new power plants: Conservation projects = fewer new power plants