Energy Efficiency and Renewable Energy G. Tyler Miller’s Living in the Environment 13 th Edition Chapter 16 G. Tyler Miller’s Living in the Environment 13 th Edition Chapter 16 Dr. Richard Clements Chattanooga State Technical Community College Dr. Richard Clements Chattanooga State Technical Community College

Key Concepts  Improving energy efficiency  Types and uses of solar energy  Types and uses of flowing water  Uses of wind energy  Types and uses of biomass  Use of hydrogen as a fuel  Use of geothermal energy  Decentralized power systems

The Importance of Improving Energy Efficiency  Net useful energy Fig p. 381  Life cycle cost Least Efficient  Incandescent lights  Internal combustion engine  Nuclear power plants

Efficiencies (fig p. 382)

Ways to Improve Energy Efficiency  Insulation  Elimination of air leaks  Air to air heat exchangers  Cogeneration  Efficient electric motors  High-efficiency lighting  Increasing fuel economy

Electric and Hybrid Cars  Rechargeable battery systems  Hybrid electric-internal combustion engine  Fuel cells  Emissions  Transition technology  Fuel cells  Emissions  Transition technology Fig p. 365

Using Solar Energy to Provide Heat  Passive solar heating -free  Active solar heating – low cost

Using Solar Energy to Provide High- Temperature Heat and Electricity  Solar thermal systems  Photovoltaic (PV) cells Fig p. 398 Fig p. 400

Solar (photovoltaic cells)  Can be stored in batteries  New tech: thin panels, nanochips in exterior paint  $1 per watt, or $.08 per kwh

Producing Electricity from Moving Water  Large Scale Hydropower – river is blocked by dam, rushing water through turbines creates power  Large Scale Hydropower – river is blocked by dam, rushing water through turbines creates power  Negative: wildlife, silting, flooding, hab. destruction, water loss (increased surface area to evaporate),  Negative: wildlife, silting, flooding, hab. destruction, water loss (increased surface area to evaporate),  Tidal power plant – more predicatable, Increase turbidity, decrease salinity, affect wildlife  Tidal power plant – more predicatable, Increase turbidity, decrease salinity, affect wildlife  Wave power plant- not commercially available.  Small Scale Hydropower- waterwheel creates power, does not affect wildlife, 100 kW or less, requires specific flow

Producing Electricity from Heat Stored in Water  Ocean thermal energy conversion (OTEC)  Heat engine between area of warm water and cooler water, as it passes through, creates energy. $0.07 per kwh, not widely used yet  Ocean thermal energy conversion (OTEC)  Heat engine between area of warm water and cooler water, as it passes through, creates energy. $0.07 per kwh, not widely used yet  Saline solar ponds- due to salinity heat trapped at bottom is used for thermal energy for local buildings –rural and developing areas, Evaporated freshwater must be replaced. Low efficiency.  Saline solar ponds- due to salinity heat trapped at bottom is used for thermal energy for local buildings –rural and developing areas, Evaporated freshwater must be replaced. Low efficiency.  Freshwater solar ponds

Producing Electricity from Wind Fig p. 402 Fig p. 402

Wind AdvantagesDisadvantages

Producing Energy from Biomass  Biofuels  Biomass plantations  Crop residues  Animal manure  Biogas  Ethanol  Methanol Fig p. 404 Fig p. 404

The Solar-Hydrogen Revolution  Extracting hydrogen efficiently  Storing hydrogen  Fuel cells Fig p. 386

Geothermal Energy  Geothermal reservoirs  Dry steam  Wet steam  Hot water  Molten rock  Hot dry-rock zones Fig p. 409

Geothermal Reservoirs Fig p. 410

Entering the Age of Decentralized Micropower  Centralized power systems  Decentralized power systems  Micropower systems Fig p. 411 Fig p. 411

Solutions: A Sustainable Energy Strategy Fig p. 414