New Renewable Energy Alternatives

New Renewable Energy Alternatives

1. Quick Information

   • “New” renewable are a group of alternative energy sources that include the sun, wind, geothermal heat, and ocean water
   • New renewable provide energy for electricity, heating, fuel for vehicles
   • New renewables provide only 1% of energy
     • Only 20% of our electricity is from renewable sources (Four-fifths of that is from hydropower)
       • Wind power is growing at 50% per year
     • Most renewable energy is more expensive than non-renewables

2. Benefits For Renewable Energy

   • Alleviating air pollution and greenhouse gas emissions
   • They are inexhaustible, unlike fossil fuels
   • They help diversify a country’s energy economy
   • They create jobs, income, and taxes, especially in rural areas
     • Green-collar jobs: design, installation, maintenance, and management of renewable energy technologies

3. Solar Energy

   • Def: Energy from the sun
     • Each square meter of Earth receives about 1 kilowatt of solar energy = 17 times the energy of a lightbulb
   • Benefits
     • PV cells and other technologies are use no fuel, are quiet and safe, contain no moving parts, require little maintenance, and do not require a turbine or generator
       • An average unit can produce energy for 20–30 years
     • They allow local, decentralized control over power
     • Developing nations can use solar cookers to replace the gathering of firewood, decreasing environmental and social stress
       • Low cost ($2–10 each) makes them available to impoverished areas
     • Green-collar jobs are being created
   • They reduce the emission of greenhouse gases and air pollution compared to fossil fuels
   • Drawbacks
     • Not all regions are sunny enough to provide enough power, given current technology
     • Solar power is an intermittent source
       • Daily and seasonal variation can limit stand-alone systems
         • They need storage (e.g., batteries) and backup power
     • Up-front costs are high
       • Fossil fuels and nuclear energy are favored over solar
         • Prices are declining and technologies are improving

4. Wind Power

   • Def: A source of renewable energy, in which kinetic energy from the passage of the wind through wind turbines is used to generate
     • Wind Turbines: A mechanical assembly that converts the wind's kinetic energy into electrical energy
       • Wind farms: A development involving a group of wind turbines
         • Turbines yaw— rotate back and forth with wind direction
   • Benefits
     • Wind produces no emissions once installed
       • Wind power can be used on many scales
     • It is more efficient than conventional power sources
     • Turbines use less water than conventional power plants
       • Advancing technology is also reducing the cost of wind farm construction
     • Farmers and ranchers can lease their land
   • Offshore Sites
     • Wind speeds are 20% greater over water than over land
     • Currently, turbines are limited to shallow water
     • Over 1800 wind turbines are operating in 65 wind farms in the waters of 10 European countries
   • Drawbacks
     • An intermittent resource; no control over when it will occur
     • Varies place to place
     • Contient-wide transmission networks need to be enhanced
     • NIMBY (Not in my backyard)
   • 15% of U.S. energy demand could be met using 16,600 mi2 of land

5. Geothermal power reduces greenhouse gas emissions

   • But it may not be sustainable if the plant withdraws water faster than it can be recharged
     • Water of many hot springs has salts and minerals that corrode equipment and pollute the air

6. Wave energy = the notion of wave is harnessed and converted from mechanical energy into electricity

   • Some designs are for offshore facilities and involve floating devices that move up and down the waves
     • Kinetic energy from the natural motion of ocean water can generate electrical power

7. Tidal energy = energy harnessed from dams that cross the outlets of tidal basins

   • Water is trapped behind gates
   • Outgoing tides turn turbines to generate electricity
   • Tidal stations release few or no pollutant emissions
   • Ocean thermal energy conversion (OTEC): uses temperature differences between the ocean’s warm surface water and cold deep water