Zusammenfassung der Ressource
New Renewable Energy Alternatives
- 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
- 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
- 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
- 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
- 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
- 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
- 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