1. Chap 16 Energy Efficiency and Renewable Energy

2. Iceland’s Vision of Renewable Energy
3/4 of island is covered by volcanoes, glaciers, & hot springs
20 active volcanoes
¾ of its energy from geothermal & hydroelectric
Imports oil for cars, factories & fishing boats
Proposing using water- to power vehicles in future- hydrogen power
Only bi-product is water vapor no CO2
st commercial hydrogen refueling station

3. 16-1 Energy Efficiency
Improving energy efficiency could save up to 43% of energy we use
Energy conservation- strategy to decrease energy use by reducing unnecessary waste of energy
Improve energy efficiency is best way- how much we can get from each unit of energy
41% of energy loss is unavoidable because of Law of Thermodynamics
43% of U.S energy loss due to inefficient lighting, heating, cars, power plants

4. Energy Efficiency
Canada & developing countries less efficient than U.S, Japan & Germany 2-3 times more efficient
Advantages of reducing energy waste:
Quick and clean
Usually the cheapest to provide more energy
Reduce pollution and degradation
Slow global warming
Increase economic and national security

5. SOLUTIONS Reducing Energy Waste Prolongs fossil fuel supplies
Reduces oil imports and improves energy security
Very high net energy yield
Low cost
Reduces pollution and environmental degradation
Figure 16.3
Advantages of reducing unnecessary energy waste and thereby improving energy efficiency. Global improvements in energy efficiency could save the world an average of about $1.9 million per minute! Question: Which two of these advantages do you think are the most important? Why?
Buys time to phase in renewable energy
Creates local jobs
Fig. 16-3, p. 401

6. Net Energy Efficiency
Net energy efficiency- determined by combining the efficiencies of all steps in energy conversion for a system
cumulative net efficiency=multiplying the percentage of energy available from source by the energy efficiency for that step. So 100 × 0.95 = 95%; 95 × 0.57 = 54%;.

7. 16-2 Cut Energy Waste Cutting Industry’s Energy Waste
Cogeneration or combined heat and power (CHP)- 2 useful forms of energy produced (steam & electricity) – electricity powers plant & steam heats it
Replace energy-wasting electric motors
Recycling materials
Switch from low-efficiency incandescent lighting to higher-efficiency fluorescent and LED lighting
Update- outdated & wasteful electrical grids
Utility companies promote efficient use of energy

8. Transportation Energy Waste
U.S fuel efficiency rose due to - Corporate average fuel standards (CAFE) standards
Since 1985, Fuel economy standards lower U.S. vs. many other countries
mileage standards not update & SUVs & trucks efficiency not high
2008 U.S law sets fuel efficiency to 35 mpg by 2020
Fuel-efficient cars on market less than 1% of car sales
Hidden prices in the gasoline- not paid at pump- pollution control & monitoring, road construction, military protection of oil
Should there be tax breaks for buying fuel-efficient cars, or feebate?

10. Energy Efficient Vehicles
Superefficient and ultralight cars- lighter materials
Gasoline-electric hybrid car- Prius (what to do with battery & smelter for Nickel-Cadmium battery damaging)
Plug-in hybrid electric vehicle- issues with battery life
Energy-efficient diesel car-bodiesel (lower CO2 emissions)
Electric vehicle with a fuel cell- use hydrogen gas (cost is factor)

11. Energy Efficient Buildings
20% of energy savings if utilize Passive Solar Heating in Construction, 75% savings for airtight & well insulated
Green architecture- use natural lighting, passive solar heating, geothermal heat pumps, solar hot water heaters, recycled building materials, etc.
Living or green roofs-covered w/ soil & vegetation (used for decades in Europe)
Straw bale houses- wall insides are straw plastered over with adobe-

13. LEED
U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED)
Two buildings that were designed with energy in mind
Georgia Power Company in Atlanta, GA (U.S.)
Ministry of Science and Technology Building in Beijing, China

14. More Efficient Existing Buildings
Insulate and plug leaks
Use energy-efficient windows
Stop other heating and cooling losses-
Heat houses more efficiently-geothermal or natural gas
Heat water more efficiently-solar heating & tankless water heater
Use energy-efficient appliances-
Use energy-efficient lighting

15. Attic
• Hang reflective foil near
roof to reflect heat.
• Use house fan.
• Be sure attic insulation is
at least 30 centimeters
(12 inches).
Outside
Plant deciduous trees to block summer sun and let in winter sunlight.
Bathroom
• Install water-saving toilets, faucets, and shower heads.
• Repair water leaks promptly.
Other rooms
• Use compact fluorescent
lightbulbs or LEDs and avoid
using incandescent bulbs
wherever possible.
• Turn off lights, computers, TV,
and other electronic devices
when they are not in use.
• Use high efficiency windows;
use insulating window covers
and close them at night and
on sunny, hot days.
• Set thermostat as low as you
can in winter and as high as
you can in summer.
• Weather-strip and caulk doors,
windows, light fixtures, and
wall sockets.
• Keep heating and cooling
vents free of obstructions.
• Keep fireplace damper closed
when not in use.
• Use fans instead of, or along
with, air conditioning.
Kitchen
• Use microwave rather than stove or oven as much as possible.
• Run only full loads in
dishwasher and use low- or no-heat drying.
• Clean refrigerator coils
regularly.
Figure 16.9
Individuals Matter: Ways in which you can save energy where you live.
Basement or utility room
• Use front-loading clothes washer. If possible run only full loads with warm or cold water.
• Hang clothes on racks for drying.
• Run only full loads in clothes dryer and use lower heat setting.
• Set water heater at 140° if dishwasher is used and 120° or lower if no dishwasher is used.
• Use water heater thermal blanket.
• Insulate exposed hot water pipes.
• Regularly clean or replace furnace filters.
Fig. 16-9, p. 409

16. Still wasting energy Energy market price still low
Few large and lasting govt tax breaks for energy efficient homes
Rebound effect- save money due to improved efficiency = raise temp in winter lower in summer

17. 16-3 Solar Energy
Passive solar heating system- absorbs & stores energy during direct sunlight w/o pumps & fans
Active solar heating system- absorbs & stores energy from sun using fluids, air etc. that are pumped through collectors
Countries using solar energy to heat water

18. Vent allows hot air to escape in summer
Summer sun
Heavy insulation
Winter sun
Superwindow
Superwindow
Figure 16.10
Solutions: passive and active solar heating for a home.
Stone floor and wall for heat storage
PASSIVE
Fig a, p. 411

19. Heat to house (radiators or forced air duct)
Solar collector
Heat to house (radiators or forced air duct)
Pump
Heavy insulation
Super- window
Hot water tank
Heat exchanger
Figure 16.10
Solutions: passive and active solar heating for a home.
ACTIVE
Fig b, p. 411

20. TRADE-OFFS Passive or Active Solar Heating Advantages Disadvantages
Energy is free
Need access to sun 60% of time
Net energy is moderate (active) to high (passive)
Sun can be blocked by trees and other structures
Quick installation
Environmental costs not included in market price
No CO2 emissions Very low air and water pollution
Figure 16.11
Advantages and disadvantages of heating a house with passive or active solar energy (Concept 16-3). Question: Which single advantage and which single disadvantage do you think are the most important? Why?
Need heat storage system
Very low land disturbance (built into roof or windows)
High cost (active)
Active system needs maintenance and repair
Moderate cost (passive)
Active collectors unattractive
Fig , p. 412

21. We Can Cool Buildings Naturally
Technologies available
Superinsulation and high-efficiency windows
Overhangs or awnings on windows
Light-colored roof
Reflective insulating foil in an attic
Geothermal pumps
Plastic earth tubes underground 21

22. Sunlight for High Temperature Electricity Generation
Solar thermal systems
Central receiver system
Other collecting systems
Unfeasible for widespread use
High cost
Low new energy yields
Limited suitable sites
Sunny, desert sites 22

23. Solar for Cooking
Use sunlight instead of wood, oil, gas, or electricity
Cooks just as well, sometimes in same amount of time, sometimes start in morning & finish by evening (solar crockpot)

24. Solar for Electricity Photovoltaic (PV) cells (solar cells)
Convert solar energy to electric energy
Solar-cell power plants
Near Tucson, AZ (U.S.)
2007: Portugal
Key problem
High cost of producing electricity
Will the cost drop with
Mass production
New designs
Nanotechnology

25. Solar-Cell Power Plant in Arizona, U. S
Solar-Cell Power Plant in Arizona, U.S., Is the Largest Solar-Cell Power Plant 25

26. Boron- enriched silicon
Single solar cell
Boron- enriched silicon
Junction
Roof options
Phosphorus- enriched silicon
Panels of solar cells
Solar shingles
Figure 16.17
Solutions: Photovoltaic (PV) or solar cells can provide electricity for a house or other building using solar-cell roof shingles, as shown in this house in Richmond Surrey, England. Solar-cell roof systems that look like a metal roof are also available. In addition, new thin-film solar cells can be applied to windows and outside walls.
Fig a, p. 415

27. Solar Power is Expanding
Solar cells: 0.2% of the world’s electricity
2040: could solar cells produce 16%?
Nanosolar: California (U.S.)
Germany: huge investment in solar cell technology
General Electric: entered the solar cell market

28. TRADE-OFFS Solar Cells Advantages Disadvantages Need access to sun
Fairly high net energy yield
Low efficiency
Work on cloudy days
Need electricity storage system or backup
Quick installation
Easily expanded or moved
Environmental costs not included in market price
No CO2 emissions
High costs (but should be competitive in 5–15 years)
Low environmental impact
Figure 16.20
Advantages and disadvantages of using solar cells to produce electricity (Concept 16-3). Question: Which single advantage and which single disadvantage do you think are the most important? Why?
Last 20–40 years
High land use (solar-cell power plants) could disrupt desert areas
Low land use (if on roof or built into walls or windows)
Reduces dependence on fossil fuels
DC current must be converted to AC
Fig , p. 417

29. 16-4 Electricity from Water Cycle
Hydropower
World’s leading renewable energy source used to produce electricity
Hydroelectric power: Iceland
Micro-hydropower generators

30. Tidal Energy Produce electricity from flowing water
Ocean tides and waves
So far, power systems are limited
Norway
New York City
Disadvantages
Few suitable sites
High costs
Equipment damaged by storms and corrosion

31. 16-5 Wind Energy Wind: indirect form of solar energy
Captured by turbines
Converted into electrical energy
Second fastest-growing source of energy
Wind farms: on land and offshore
“Saudi Arabia of wind power”
North Dakota
South Dakota
Kansas
Texas
How much electricity is possible with wind farms in those states?

32. Wind Power

33. Producing Electricity with Windpower
Countries with the highest total installed wind power capacity
Germany
United States
Spain
India
Denmark
Installation is increasing in several other countries

34. TRADE-OFFS Wind Power Advantages Disadvantages
Moderate to high net energy yield
Steady winds needed
Backup systems needed when winds are low
High efficiency
Moderate capital cost
Plastic components produced from oil
Low electricity cost (and falling)
Environmental costs not included in market price
Very low environmental impact
High land use for wind farm
No CO2 emissions
Figure 16.23
Advantages and disadvantages of using wind to produce electricity (Concepts 16-5). With sufficient and consistent incentives, wind power could supply more than 10% of the world’s electricity and 10–25% of the electricity used in the United States by Question: Which single advantage and which single disadvantage do you think are the most important? Why?
Quick construction
Visual pollution
Easily expanded
Noise when located near populated areas
Can be located at sea
Land below turbines can be used to grow crops or graze livestock
Can kill birds and interfere with flights of migratory birds
Fig , p. 421

35. 16-5- Biomass as Energy Source
Biofuels
Production of solid mass fuel
Plant fast-growing trees
Biomass plantations
Collect crop residues and animal manure

36. TRADE-OFFS Solid Biomass Advantages Disadvantages
Large potential supply in some areas
Nonrenewable if harvested unsustainably
Moderate to high environmental impact
Moderate costs
Environmental costs not included in market price
No net CO2 increase if harvested, burned, and replanted sustainably
Increases CO2 emissions if harvested and burned unsustainably
Plantation can be located on semiarid land not needed for crops
Low photosynthetic efficiency
Figure 16.24
General advantages and disadvantages of burning solid biomass as a fuel (Concept 16-6A). Question: Which single advantage and which single disadvantage do you think are the most important? Why?
Soil erosion, water pollution, and loss of wildlife habitat
Plantation can help restore degraded lands
Plantations could compete with cropland
Can make use of agricultural, timber, and urban wastes
Often burned in inefficient and polluting open fires and stoves
Fig , p. 422

37. Plants & Plant Wastes to Liquid
Liquid biofuels
Biodiesel
Ethanol
Biggest producers of biofuel
Brazil
United States
The European Union
China

38. Liquid BioFuels Studies warn of problems:
Major advantages over gasoline and diesel fuel produced from oil
Biofuel crops can be grown almost anywhere
No net increase in CO2 emissions if managed properly
Available now
Studies warn of problems:
Decrease biodiversity
Increase soil degrading, erosion, and nutrient leaching
Push farmers off their land
Raise food prices

39. TRADE-OFFS Biodiesel Advantages Disadvantages Reduced CO emissions
Increased NOx emissions and more smog
Reduced CO2 emissions (78%)
Higher cost than regular diesel
High net energy yield for oil palm crops
Environmental costs not included in market price
Low net energy yield for soybean crops
Moderate net energy yield for rapeseed crops
May compete with growing food on cropland and raise food prices
Figure 16.25
General advantages and disadvantages of using biodiesel as a vehicle fuel, compared to gasoline. Question: Which single advantage and which single disadvantage do you think are the most important? Why?
Reduced hydrocarbon emissions
Loss and degradation of biodiversity from crop plantations
Better gas mileage (40%)
Can make engines hard to start in cold weather
Potentially renewable
Fig , p. 424

41. Case Study: Is Ethanol the Answer?
Ethanol converted to gasohol
Brazil: “Saudi Arabia of sugarcane”
Saved $50 billion in oil import costs since the 1970s
United States: ethanol from corn
Reduce the need for oil imports?
Slow global warming?
Reduce air pollution?
Cellulosic ethanol: alternative to corn ethanol
Sources
Switchgrass
Crop residues
Municipal wastes 41

42. TRADE-OFFS Ethanol Fuel Advantages Disadvantages High octane
Lower driving range
Low net energy yield (corn)
Some reduction in CO2 emissions (sugarcane bagasse)
Higher CO2 emissions (corn)
Much higher cost
High net energy yield (bagasse and switchgrass)
Environmental costs not included in market price
Figure 16.27
General advantages and disadvantages of using ethanol as a vehicle fuel, compared to gasoline. (Concept 16-6B). Question: Which single advantage and which single disadvantage do you think are the most important? Why?
May compete with growing food and raise food prices
Reduced CO emissions
Can be sold as E85 or pure ethanol
Higher NOx emissions and more smog
Corrosive
Potentially renewable
Can make engines hard to start in cold weather
Fig , p. 426

43. 16-7 Geothermal Energy Geothermal energy: heat stored in
Soil
Underground rocks
Fluids in the earth’s mantle
Geothermal heat pump system
Energy efficient and reliable
Environmentally clean
Cost effective to heat or cool a space

44. Geothermal Energy Hydrothermal reservoirs
Iceland
Geothermal energy: two problems
High cost of tapping large-scale hydrothermal reservoirs
Dry- or wet-steam geothermal reservoirs could be depleted
Hot, dry rock: another potential source of geothermal energy?

45. Natural Capital: A Geothermal Heat Pump System Can Heat or Cool a House45

46. TRADE-OFFS Geothermal Energy Advantages Disadvantages
Very high efficiency
Scarcity of suitable sites
Can be depleted if used too rapidly
Moderate net energy at accessible sites
Environmental costs not included in market price
Lower CO2 emissions than fossil fuels
CO2 emissions
Low cost at favorable sites
Figure 16.29
Advantages and disadvantages of using geothermal energy for space heating and for producing electricity or high-temperature heat for industrial processes (Concept 16-7). Question: Which single advantage and which single disadvantage do you think are the most important? Why?
Moderate to high local air pollution
Low land use and disturbance
Noise and odor (H2S)
High cost except at the most concentrated and accessible sources
Moderate environmental impact
Fig , p. 428

47. 16-8 Hydrogen as Energy Source
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
Fuel cells are the best way to use hydrogen
CO2 levels dependent on method of hydrogen production

48. Challenges to Hydrogen
Production and storage of H2
Hydrogen-powered vehicles: prototypes available
Can we produce hydrogen on demand?
Larger fuel cells

49. TRADE-OFFS Hydrogen Advantages Disadvantages Fuel cell
Can be produced from plentiful water
Not found as H2 in nature
Energy is needed to produce fuel
Low environmental impact
Negative net energy
Renewable if produced from renewable energy resources
CO2 emissions if produced from carbon-containing compounds
No CO2 emissions if produced from water
Environmental costs not included in market price
Good substitute for oil
Nonrenewable if generated by fossil fuels or nuclear power
Competitive price if environmental and social costs are included in cost comparisons
High costs (that may eventually come down)
Figure 16.31
Advantages and disadvantages of using hydrogen as a fuel for vehicles and for providing heat and electricity (Concept 16-8). Question: Which single advantage and which single disadvantage do you think are the most important? Why?
Will take 25 to 50 years to phase in
Easier to store than electricity
Short driving range for current fuel-cell cars
Safer than gasoline and natural gas
No fuel distribution system in place
Nontoxic
Excessive H2 leaks may deplete ozone in the atmosphere
High efficiency (45–65%) in fuel cells
Fig , p. 430

50. SOLUTIONS Making the Transition to a More Sustainable Energy Future
More Renewable Energy
Improve Energy Efficiency
Greatly increase use of renewable energy
Increase fuel-efficiency standards for vehicles, buildings, and appliances
Provide large subsidies and tax credits for use of renewable energy
Include environmental costs in prices for all energy resources
Mandate government purchases of efficient vehicles and other devices
Encourage government purchase of renewable energy devices
Greatly increase renewable energy research and development
Provide large tax credits or feebates for buying efficient cars, houses, and appliances
Reduce Pollution and Health Risk
Offer large tax credits for investments in energy efficiency
Figure 16.33
Suggestions of various energy analysts for helping us to make the transition to a more sustainable energy future (Concept 16-9). Question: Which five of these solutions do you think are the most important? Why?
Cut coal use 50% by 2020
Phase out coal subsidies
Reward utilities for reducing demand for electricity
Levy taxes on coal and oil use
Greatly increase energy efficiency research and development
Phase out nuclear power subsidies, tax breaks, and loan guarantees
Fig , p. 432

52. What Can you Do? Shifting to Sustainable Energy Use52