Energy Efficiency and Renewable Energy Resources

Solutions:We have the answers! Energy Efficiency! 43% of energy in the US is wasted unnecessarily Incandescent bulb=5% efficient Fluorescent bulb=20% efficient Auto fleet standards = CAFE Standards (Corporate Average Fuel Economy) –12.9 mpg in 1974 –27.9 mpg today –40 mpg CAFE standard would cut gas use by 50%

Efficiencies

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

Solutions:We have the answers! Renewable Energy Resources! Biomass Hydroelectric power Geothermal Solar—passive and active Wind generation Hydrogen power

Using Solar Energy to Provide Heat and Electricity  Passive solar heating  Active solar heating

Using Solar Energy to Provide High- Temperature Heat and Electricity  Solar thermal systems  Photovoltaic (PV) cells Solar Cell Trade-Offs

Producing Electricity from Moving Water  Large-scale hydropower  Small-scale hydropower  50% of West Coast electricity  7% of US electricity  20% of World’s electricity  Major environmental impacts  High construction costs

Impacts of hydropower on salmon and other riverine spp.  Pollution  Disruption of water flow  Loss of biodiversity  Invasive species

Impacts of hydropower on Species and People_______________ Dams can provide many human benefits but: Disrupts ecological services rivers provide; e.g. 119 dams on Columbia River have caused a 94% drop in wild salmon; removing hydroelectric dams will restore native spawning grounds Displaces millions of people worldwide as reservoirs flood traditional homelands No room for expansion in the US

Producing Electricity from Wind

Producing Energy from Biomass  Biofuels  Biomass plantations  Crop residues  Animal manure  Biogas  Ethanol  Methanol

The Solar-Hydrogen Revolution  Extracting hydrogen efficiently  Storing hydrogen  Fuel cells

Geothermal Energy  Geothermal reservoirs  Dry steam  Wet steam  Hot water  Molten rock  Hot dry-rock zones

Geothermal Reservoirs

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

Creating a Sustainable Energy Future Increase fuel efficiency standards for vehicle, appliances, buildings Tax and other financial incentives for energy efficiency Subsidize renewable energy use, research and development Internalize externalities for fossil fuels By 2050: –Increase renewable energy to 50% –cut coal use by 50% –phase out nuclear altogether

Solutions: A Sustainable Energy Strategy