1. Environmental Science: Toward a Sustainable Future Richard T. Wright
Chapter 14
Renewable Energy
PPT by Clark E. Adams

2. Renewable Energy Putting solar energy to work Indirect solar energy
Renewable energy for transportation
Additional renewable-energy options
Policy for a sustainable-energy future

3. Renewable-energy Use in the United States

4. Examples of Renewable Energy Sources

5. Putting Solar Energy to Work

6. Principles of Solar Energy
Constant
Abundant
Free
Everlasting

7. Hurdles in Using Solar Energy
Collection
Conversion
Storage
Cost-effectiveness

8. Terms 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

9. Components of Active or Passive Solar Heating Systems?
Flat-plate collector
Water pump
Blowers
Heat exchanger
Improved insulation
Earthen berms

10. Solar Heating of Water: Flat-plate Solar Collector

11. Solar Water Heaters

12. Solar Space Heating

13. Solar Building Siting

14. Landscaping in Solar Heating and Cooling

15. Solar Production of Electricity
Photovoltaic Cell

16. How 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.

17. How Photovoltaic Cells Work: Part 2
Kinetic energy from sunlight dislodges electrons from lower layer – creates an electric potential between the two layers.

18. How 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.

19. The Market for PV Cells

20. Concentrating Solar Power
PV power plants
Solar-trough collectors
Power towers
Dish-engine system

21. The Solar-trough Collector

22. Power Tower

23. Solar Dish Engine System

24. Disadvantages of Solar Energy Technologies
Expense
Only works during the day
Requires backup energy sources, e.g., batteries
Some climates not sunny enough

25. Hidden Costs of Traditional Energy Sources
Air pollution
Strip-mining
Nuclear wastes

26. Indirect Solar Energy
Hydropower
Wind power
Biomass energy

27. Wind Power: Benefits or Drawbacks?
Size limitations of wind turbines
Megawatts of electricity produced
Level of pollution generated

28. Wind Power: Benefits or Drawbacks?
Level of environmental degradation
Geographical distribution of energy produced
Aesthetics

29. Biomass Energy Burning firewood Burning wastes
Burning biogas (methane)

30. Biomass 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

31. Renewable Energy and Transportation
Biofuels: ethanol and biodiesel
Hydrogen: the fuel for the future

32. Hydrogen–Oxygen Fuel Cell

33. Fuel Cells: Benefits or Drawbacks?
Substitute for fossil fuels
Pollution factor
Production technology
Portability
National distribution system

34. Additional Renewable Energy Options
Geothermal energy
Tidal power
Ocean thermal-energy conversion (OTEC)

35. Geothermal Energy: Benefits or Drawbacks?
Consistent source
Level of pollution
Cost-effectiveness
Technology required for extraction
Geographical distribution of energy produced

36. Geothermal Heat Pump System

37. Tidal Power: Benefits or Drawbacks?
Consistent source
Level of pollution
Cost-effectiveness
Technology required for extraction
Geographical distribution of energy produced

38. OTEC: 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

39. Policy for a Sustainable Energy Future
National energy policy
A clean energy blueprint

40. A 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

41. A 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).

44. End of Chapter 14