Title: Environmental Science: Toward a Sustainable Future Richard T. Wright
1Environmental Science Toward a Sustainable
Future Richard T. Wright
Chapter 14
- Renewable Energy
- PPT by Clark E. Adams
2Renewable Energy
- Putting solar energy to work
- Indirect solar energy
- Renewable energy for transportation
- Additional renewable-energy options
- Policy for a sustainable-energy future
3Renewable-energy Use in the United States
4Examples of Renewable Energy Sources
5Putting Solar Energy to Work
6Putting Solar Energy to Work
- Principles of solar energy
- Solar heating of water
- Solar space heating
- Solar production of electricity
- The promise of solar energy
7Principles of Solar Energy
Constant Abundant Free Everlasting
8Hurdles in Using Solar Energy
- Collection
- Conversion
- Storage
- Cost-effectiveness
9Terms and Definitions Solar Heating Systems
- Active moves water or air with pumps and blowers
- Passive moves water or air with natural
convection currents or gravity
10Components of Active or Passive Solar Heating
Systems?
- Flat-plate collector
- Water pump
- Blowers
- Heat exchanger
- Improved insulation
- Earthen berms
11Solar Heating of Water Flat-plate Solar Collector
12Solar Water Heaters
13Solar Space Heating
14Solar Building Siting
15Landscaping in Solar Heating and Cooling
16Required Components?
- Flat-plate collector
- Water pump
- Blowers
- Heat exchanger
- Improved insulation
- Solar hot water
- Solar space heater
- Both
17Solar Production of Electricity
Photovoltaic Cell
18How Photovoltaic Cells Work Part 1
- Each cell consists of two thin mylar layers.
- Lower layer has atoms with single electron in
outer orbit easily lost. - Upper layer has atoms lacking one electron in
outer orbit easily accepts electrons.
19How Photovoltaic Cells Work Part 2
- Kinetic energy from sunlight dislodges electrons
from lower layer creates an electric potential
between the two layers.
20How Photovoltaic Cells Work Part 3
- The potential provides the energy for an
electrical current through the rest of the
circuit. - Electrons from lower layer flow through a device
back to upper side.
21The Market for PV Cells
22Concentrating Solar Power
- PV power plants
- Solar-trough collectors
- Power towers
- Dish-engine system
23The Solar-trough Collector
24How the Solar-trough Collector Works
- The curved reflector focuses sunlight on and
heats oil in the pipe. - Heated oil used to boil water and generate steam
for driving a conventional turbogenerator.
25Power Tower
26Solar Dish Engine System
27Disadvantages of Solar Energy Technologies
- Expense
- Only works during the day
- Requires backup energy sources, e.g., batteries
- Some climates not sunny enough
28Promise of Solar Energy (More or Less?)
- The use of solar electrical power will
- create ____ reliance on coal or nuclear power.
- lead to significantly _____ acid rain.
- produce ____ electrical power for villages in
developing countries.
29Hidden Costs of Traditional Energy Sources
- Air pollution
- Strip-mining
- Nuclear wastes
30Indirect Solar Energy
- Hydropower
- Wind power
- Biomass energy
31Hydropower Benefits or Drawbacks?
- Level of pollution generated
- Level of environmental degradation
- Amount of energy produced
32Hydropower Benefits or Drawbacks?
- Geographical distribution of energy produced
- Ecological impacts above and below dam
- Societal disruptions
33Wind Power Benefits or Drawbacks?
- Size limitations of wind turbines
- Megawatts of electricity produced
- Level of pollution generated
34Wind Power Benefits or Drawbacks?
- Level of environmental degradation
- Geographical distribution of energy produced
- Aesthetics
35Biomass Energy
- Burning firewood
- Burning wastes
- Burning biogas (methane)
36Biomass Energy Benefits or Drawbacks?
- Availability of the biomass resource
- Access to the biomass resource
- Public acceptance and utilization of biomass
energy - Past history of human harvests within a maximum
sustained yield
37Renewable Energy and Transportation
- Biofuels ethanol and biodiesel
- Hydrogen the fuel for the future
38HydrogenOxygen Fuel Cell
39Fuel Cells Benefits or Drawbacks?
- Substitute for fossil fuels
- Pollution factor
- Production technology
- Portability
- National distribution system
40Additional Renewable Energy Options
- Geothermal energy
- Tidal power
- Ocean thermal-energy conversion (OTEC)
41Geothermal Energy Benefits or Drawbacks?
- Consistent source
- Level of pollution
- Cost-effectiveness
- Technology required for extraction
- Geographical distribution of energy produced
42Geothermal Heat Pump System
43Tidal Power Benefits or Drawbacks?
- Consistent source
- Level of pollution
- Cost-effectiveness
- Technology required for extraction
- Geographical distribution of energy produced
44OTEC Benefits or Drawbacks?
- In an average day the heat absorbed by the
surface water in only one square mile is
equivalent to the burning of 7,000 barrels of oil
- Cost effectiveness to capture and distribute heat
energy - Industrial interest in the OTEC alternative
45Policy for a Sustainable Energy Future
- National energy policy
- A clean energy blueprint
46National Energy Policy (True or False)
- Mandates to increase fuel efficiency in cars
- Exploitation of public lands for fossil fuel
reserves - Subsidies to producers of solar energy technology
- Research and development on renewable energy
technologies
47A Clean Energy Blueprint
- Supply side
- Establish a Renewable Portfolio Standard
- Maintain production tax credits
- Extend net metering
- Substantially increase research-and-development
on renewable energy and efficiency
48A Clean Energy Blueprint
- Demand side
- Improve efficiency standards
- Enhance building codes
- Provide incentives for combined heat and power
facilities - Raise fuel economy (CAFÉ) standards
- Increase research and development on
high-efficiency vehicles (hybrid electric and
fuel cell vehicles).
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51End of Chapter 14