Environmental Science

1
Environmental Science

• Chapter 11
• Notes 3

2
Review

• Nonrenewable resources
• Renewable Resources
• Fossil Fuels
• The energy of fossil fuels is most commonly
  turned into electricity
• A fuels suitability (5 Things)
• Availability, Cost, Energy content, Safety, By
  products
• In the US the main use of energy is for creating
  electricity
• Electricity/ Electric Generator

3
Review

• Where do we get electricity?
• Power Plants create electricity and that
  electricity is carried though a distribution grid
• 1. Energy obtained from fossil fuels or
  radioactive material
• 2. The heat turns water into steam
• 3. The steam is directed at the blades of a
  turbine, causing them to spin
• 4. The turbine is connected to a generator, the
  coils of the generator are moved
  through a magnetic field, creating
  electricity, which is sent out to the
  distribution grid

4
Conserving Energy

• Use alternative energy sources
• Energy sources that are still in development
• Energy sources other than fossil fuels
• Wash clothes with cold water instead of hot water
• Use mass transportation when possible
• Developing more energy friendly vehicles
• Ex. Hybrid cars efficient gasoline engine
  electric motor
• Have added insulation in homes around windows and
  doors and in roofs

5
Alternative Energy Sources
Water (Hydroelectric) Electricity generated
from moving water

• Advantages
• No Pollution
• Electricity
• Micro- hydropower plants
• No dams, they float
• Cheaper
• No river blockage
• Usable in remote areas

• Disadvantages
• Changes Rivers
• Changes ecosystems (due to dams)
• Expensive to get up and running

6
Alternative Energy Sources
Wind Energy is the fastest growing alternative
source of energy in the world its powered by
the sun. Wind turbines convert the movement into
electricity.

• Advantages
• Creates Electricity
• Wind turbines have gotten more cost effective

• Disadvantages
• Bulky
• Noisy
• Not always windy
• Difficult to transport the energy from where its
  created to where it will be used

7
Alternative Energy Sources
Nuclear Fission Splitting of atoms (U) A nuclear
reactor (surrounded by a thick pressure vessel
and is filled with a cooling liquid)

• Disadvantages
• Radiation
• Safety (Chernobyl) unauthorized test/safety
  devices turned off/ many dead cancer
• Expensive
• Many less being built because of the cost
• Storage sites for waste (remote and geologically
  stable)
• Waste remains radioactive for 1000s of years

• Advantages
• Reliable
• Lots of energy
• Does not produce air pollution

8
Alternative Energy Sources
Nuclear Fusion combining of atoms (H) like at
the sun

• Advantages
• 1000 times more energy than fission
• Is very abundant
• Can be burned as fuel
• Is used in fuel cells
• No air pollution

• Disadvantages
• Safety
• Atomic nuclei must be heated to extremely high
  temps and nuclei must be maintained at very high
  levels and properly contained

9
Alternative Energy Sources
Solar Energy Electricity generated from the
sunalso contained in fossil fuels, drives the
wind, water cycles, etc.

• Advantages
• No Pollution
• Electricity
• Heat

• Disadvantages
• Not consistent
• Expensive

10
Alternative Energy Sources
Biomass Electricity generated from many places.
Burning trees, ethanol from fermenting corn, dung
fired power stations, fermenting manure to
produce methane, etc.

• Advantages
• Electricity
• Heat

• Disadvantages
• Habitat loss
• Soil erosion
• Air pollution

In developing countries, wood and dung are the
most common biomass fuels, they are used for
heating and cooking. In developed countries, we
use it to create alternative fuels (ethanol), or
producing methane to burn)
11
Alternative Energy Sources
Geothermal Electricity generated from areas
where deposits of water have been heated inside
the Earth. The heated water or steam is then
pumped from inner rock formations.

• Advantages
• Electricity
• Heat
• Used in homes by circulating fluid underground to
  absorb heat from the Earth
• Lots of energy

• Disadvantages
• Not much availability (ex. Old faithful)

12
Alternative Energy Sources
Clean Burning Coal Electricity generated from
coal (remains of plants that have stored energy
from photosynthesis/the sun). Has many
Impurities washed out or trapped, reducing air
pollution

• Advantages
• Electricity
• Heat
• Can reduce sulfur emissions (57 of electricity
  in the US is from burning coal)

• Disadvantages
• Still produces air pollution
• Expensive
• Not a current working solution