Renewable Energy 164 What Are the Advantages and Disadvantages of Using Hydropower Concept 164 We can use water flowing over dams tidal flows and ocean waves to generate electricity but environmental concerns and limited availability of suitable sites may limit the use of these energy re ID: 726536
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Slide1
Chapter 16
Energy Efficiency and
Renewable EnergySlide2
16-4 What Are the Advantages and Disadvantages of Using Hydropower
Concept 16-4
We can use water flowing over dams, tidal flows, and ocean waves to generate electricity, but environmental concerns and limited availability of suitable sites may limit the use of these energy resources. Slide3
We Can Produce Electricity from Falling and Flowing Water
Hydropower
Uses kinetic energy of moving water
Indirect form of solar energy
World
’
s leading renewable energy source used to produce electricity
Advantages and disadvantages
Micro-hydropower generatorsSlide4
Tradeoffs: Dams and Reservoirs
Fig. 13-13, p. 328Slide5
Fig. 13-13b, p. 328
Powerlines
Reservoir
Dam
Intake
Powerhouse
TurbineSlide6
Trade-Offs: Large-Scale Hydropower, Advantages and Disadvantages
Fig. 16-22, p. 415Slide7
Tides and Waves Can Be Used to Produce Electricity
Produce electricity from flowing water
Ocean tides and waves
So far, power systems are limited
Disadvantages
Few suitable sites
High costs
Equipment damaged by storms and corrosionSlide8
16-5 What Are the Advantages and Disadvantages of Using Wind Power?
Concept 16-5
When we include the environmental costs of using energy resources in the market prices of energy, wind power is the least expensive and least polluting way to produce electricity. Slide9
Using Wind to Produce Electricity Is an Important Step toward Sustainability (1)
Wind: indirect form of solar energy
Captured by turbines
Converted into electrical energy
Second fastest-growing source of energy
What is the global potential for wind energy?
Wind farms: on land and offshoreSlide10
World Electricity from Wind Energy
Figure 12, Supplement 9Slide11
Solutions: Wind Turbine and Wind Farms on Land and Offshore
Fig. 16-23, p. 417Slide12
Fig. 16-23a, p. 417
Gearbox
Electrical generator
Power cable
Wind turbineSlide13
Fig. 16-23b, p. 417
Wind farmSlide14
Fig. 16-23c, p. 417
Wind farm (offshore)Slide15
Wind Turbine
Fig. 16-24, p. 417Slide16
Using Wind to Produce Electricity Is an Important Step toward Sustainability (2)
Countries with the highest total installed wind power capacity
Germany
United States
Spain
India
Denmark
Installation is increasing in several other countriesSlide17
Using Wind to Produce Electricity Is an Important Step toward Sustainability (3)
Advantages of wind energy
Drawbacks
Windy areas may be sparsely populated – need to develop grid system to transfer electricity
Winds die down; need back-up energy
Storage of wind energy
Kills migratory birds
“
Not in my backyard
”Slide18
Trade-Offs: Wind Power
Fig. 16-25, p. 418Slide19
Case Study: The Astounding Potential of Wind Power in the United States
“
Saudi Arabia of wind power
”
North Dakota
South Dakota
KansasTexas
How much electricity is possible with wind farms in those states?
Could create up to 500,000 jobsSlide20
United States Wind Power Potential
Figure 24, Supplement 8Slide21
16-6 Advantages and Disadvantages of Using Biomass as an Energy Source
Concept 16-6A
Solid biomass is a renewable resource for much of the world
’
s population, but burning it faster than it is replenished produces a net gain in atmospheric greenhouse gases, and creating biomass plantations can degrade soil biodiversity.
Concept 16-6B
We can use liquid biofuels derived from biomass in place of gasoline and diesel fuels, but creating biofuel plantations can degrade soil and biodiversity and increase food prices and greenhouse gas emissions.
Slide22
We Can Get Energy by Burning Solid Biomass
Biomass
Plant materials and animal waste we can burn or turn into biofuels
Production of solid mass fuel
Plant fast-growing trees
Biomass plantations
Collect crop residues and animal manure
Advantages and disadvantagesSlide23
Trade-Offs: Solid Biomass
Fig. 16-26, p. 420Slide24
We Can Convert Plants and Plant Wastes to Liquid Biofuels (1)
Liquid biofuels
Biodiesel
Ethanol
Biggest producers of biofuel
The United States
BrazilThe European Union
ChinaSlide25
We Can Convert Plants and Plant Wastes to Liquid Biofuels (2)
Major advantages over gasoline and diesel fuel produced from oil
Biofuel crops can be grown almost anywhere
No net increase in CO
2
emissions if managed properly
Available nowSlide26
We Can Convert Plants and Plant Wastes to Liquid Biofuels (3)
Studies warn of problems:
Decrease biodiversity
Increase soil degrading, erosion, and nutrient leaching
Push farmers off their land
Raise food prices
Reduce water supplies, especially for corn and soySlide27
Case Study: Is Biodiesel the Answer?
Biodiesel production from vegetable oil from various sources
95% produced by the European Union
Subsidies promote rapid growth in United States
Advantages and disadvantagesSlide28
Trade-Offs: Biodiesel
Fig. 16-27, p. 421Slide29
Case Study: Is Ethanol the Answer? (1)
Ethanol from plants and plant wastes
Brazil produces ethanol from sugarcane
Environmental consequences
United States: ethanol from corn
Low net energy yield
Reduce the need for oil imports?
Harm food supply
Air pollution and climate change? Slide30
Case Study: Is Ethanol the Answer? (2)
Cellulosic ethanol:
alternative to corn ethanol
Switchgrass
Crop residues
Municipal wastesAdvantages and disadvantagesSlide31
World Ethanol Production
Figure 13, Supplement 9Slide32
Bagasse is Sugarcane Residue
Fig. 16-28, p. 421Slide33
Natural Capital: Rapidly Growing Switchgrass
Fig. 16-29, p. 423Slide34
Trade-Offs: Ethanol Fuel
Fig. 16-30, p. 423Slide35
Case Study: Getting Gasoline and Diesel Fuel from Algae and Bacteria (1)
Algae remove CO
2
and convert it to oil
Not compete for cropland = not affect food prices
Wastewater/sewage treatment plants
Could transfer CO2 from power plantsAlgae challenges
Need to lower costs
Open ponds vs. bioreactors
Affordable ways of extracting oil
Scaling to large productionSlide36
Case Study: Getting Gasoline and Diesel Fuel from Algae and Bacteria (2)
Bacteria: synthetic biology
Convert sugarcane juice to biodiesel
Need large regions growing sugarcane
Producing fuels from algae and bacteria can be done almost anywhereSlide37
16-7 What Are the Advantages and Disadvantages of Geothermal Energy?
Concept 16-7
Geothermal energy has great potential for supplying many areas with heat and electricity, and it has a generally low environmental impact, but sites where it can be used economically are limited. Slide38
Getting Energy from the Earth
’
s
Internal Heat (1)
Geothermal energy
:
heat stored inSoil
Underground rocks
Fluids in the earth
’
s mantle
Geothermal heat pump systemEnergy efficient and reliableEnvironmentally cleanCost effective to heat or cool a spaceSlide39
Natural Capital: A Geothermal Heat Pump System Can Heat or Cool a House
Fig. 16-31, p. 425Slide40
Getting Energy from the Earth
’
s
Internal Heat (2)
Hydrothermal reservoirs
U.S. is the world
’s largest producer
Hot, dry rock
Geothermal energy problems
High cost of tapping hydrothermal reservoirs
Dry- or wet-steam geothermal reservoirs could be depleted
Could create earthquakesSlide41
Geothermal Sites in the United States
Figure 26, Supplement 8Slide42
Geothermal Sites Worldwide
Figure 25, Supplement 8Slide43
Geothermal Power Plant in
Iceland
Snedeker has been there!!!
Fig. 16-32, p. 425Slide44
Trade Offs: Geothermal Energy
Fig. 16-33, p. 426Slide45
16-8 The Advantages and Disadvantages of Using Hydrogen as an Energy Source
Concept 16-8
Hydrogen fuel holds great promise for powering cars and generating electricity, but for it to be environmentally beneficial, we would have to produce it without the use of fossil fuels. Slide46
Will Hydrogen Save Us? (1)
Hydrogen as a fuel
Eliminate most of the air pollution problems
Reduce threats of global warming
Some challenges
Chemically locked in water and organic compounds = net negative energy yield
Expensive fuel cells are the best way to use hydrogen
CO
2
levels dependent on method of hydrogen productionSlide47
Will Hydrogen Save Us? (2)
Net negative energy yield
Production and storage of H
2
Hydrogen-powered vehicles: prototypes available
Can we produce hydrogen on demand?
Larger fuel cells – fuel-cell stacksSlide48
A Fuel Cell Separates the Hydrogen Atoms
’
Electrons from Their Protons
Fig. 16-34, p. 427Slide49
Trade-Offs: Hydrogen, Advantages and Disadvantages
Fig. 16-35, p. 428Slide50
Science Focus: The Quest to Make Hydrogen Workable
Bacteria and algae can produce hydrogen through biodegrading organic material
Use electricity from renewable energy sources to produce hydrogen
Storage options for hydrogenSlide51
16-9 How Can We Make the Transition to a More Sustainable Energy Future?
Concept 16-9
We can make the transition to a more sustainable energy future if we greatly improve energy efficiency, use a mix of renewable energy resources, and include environmental costs in the market prices of all energy resources.Slide52
Choosing Energy
Paths
How will energy policies be created?
Hard energy
path
Soft energy
path
General conclusions
Gradual shift to smaller, decentralized
micropower
systems
Transition to a diverse mix of locally available renewable energy resources Improved energy efficiencyFossil fuels will still be used in large amounts Natural gas is the best choiceSlide53
Solutions: Decentralized Power System
Fig. 16-36, p. 430Slide54
Solutions: Making the Transition to a More Sustainable Energy Future
Fig. 16-37, p. 431Slide55
Economics, Politics, Education, and Sustainable Energy Resources
Government strategies:
Keep the prices of selected energy resources artificially low to encourage their use
Keep energy prices artificially high for selected resources to discourage their use
Consumer educationSlide56
What Can you Do? Shifting to More Sustainable Energy Use
Fig. 16-38, p. 432Slide57
Three Big Ideas
We should evaluate energy resources on the basis of their potential supplies, how much net useful energy they provide, and the environmental impacts of using them.
Using a mix of renewable energy sources—especially solar, wind, flowing water, sustainable biofuels, and geothermal energy—can drastically reduce pollution, greenhouse gas emissions, and biodiversity losses.Slide58
Three Big Ideas
Making the transition to a more sustainable energy future will require sharply reducing energy waste, using a mix of environmentally friendly renewable energy resources, and including the harmful environmental costs of energy resources in their market prices.