2. There are a wide range of energy resources, with different security of
supply and environmental issues:
Non-renewable Renewable Recyclable
A finite stock of resources,
which will run out
A flow of resources, which
is infinite in human terms
Can be used repeatedly, if
managed carefully
Coal, oil, gas (plus oil shale,
tar sands, lignite etc.)
Wind, solar, hydroelectric,
wave, tidal, geothermal
Biomass, nuclear (with
reprocessing of fuel)
âąSignificant environmental
impacts during extraction
(oil wells, opencast mines)
âąGreenhouse gas emissions
during use, and acidic
emissions
âąMay require large areas
(solar arrays, wind farms)
for operation.
âąNIMBY issues.
âąLimited / no greenhouse
emissions.
âąLarge land area needed
for biomass.
âąLargely unresolved
issues of storing high
level radioactive waste.
Energy classification
3. Traditional vs alternative energy options
Nuclear power stations work similar to
fossil fuel power plants, except for the
fact that the heat is produced by the
reaction of uranium inside a nuclear
reactor. The reactor uses uranium rods,
the atoms of which are split in the
process of fission, releasing a large
amount of energy.
Coal is the most abundant fossil fuel in
terms of remaining reserves, and is low
cost. Various clean coal technologies
have been developed but they are not
widely used. Coal can be used to make
gas.
Wind turbines make useful energy by
harnessing the power of the wind to
propel the blades of wind turbines.
These turbines cause the rotation of
magnets, which creates electricity. Wind
towers are usually built together on
wind farms.
Solar power involves using solar cells to
convert sunlight into electricity, using
sunlight hitting solar thermal panels to
convert sunlight to heat water or air,
using sunlight hitting a parabolic mirror
to heat water (producing steam), or
using sunlight entering windows for
passive solar heating of a building.
Geothermal energy harnesses the heat
energy present underneath the Earth.
The hot rocks heat water to produce
steam. When holes are drilled in the
region, the steam that shoots up is
purified and is used to drive turbines,
which power electric generators.
Unlike the other energy sources,
hydrogen fuel must be manufactured
with a net loss of energy. In using
hydrogen as a fuel, there are two
alternatives: (1) a fuel cell can convert
the chemicals hydrogen and oxygen into
water, and in the process, produce
electricity, or (2) hydrogen can be
burned in an internal combustion
engine.
In hydro energy, the gravitational
descent of a river is compressed from a
long run to a single location with a dam.
This creates a location where
concentrated pressure and flow can be
used to turn turbines or water wheels,
which drive an electric generator.
Ethanol fuel is a biofuel alternative to
gasoline (also biodiesel). Current
interest in ethanol lies in production
derived from crops (bio-ethanol), and
there's discussion about whether it is a
sustainable energy resource that may
offer environmental and long-term
economic advantages over fossil fuels.
Waste-to-energy in its strictest sense
refers to any waste treatment that
creates energy in the form of electricity
or heat from a waste source that would
have been disposed of in landfill. More
advanced Waste-to-energy processes
result in usable fuel commodity, such as
hydrogen or ethanol, upon completion
of process
4. Different sources of energy
âą In pairs write down all the different energy
sources you can think of?
âą How could you then classify them?
5. Different sources of energy (p3)
1. Fossil Fuels
Brief history of fossil fuels use here
2. Renewable energy
Video here on the increasing use of renewable
in the EU
3. Primary energy sources