Transcript Large Scale Sources of Electrical Energy

Lesson 4


Around 89% of all of the energy resources
used in Canada are non-renewable.
If focusing on electricity generation alone. 59
- 69% of electricity in Canada is from
Hydroelectric, the rest is from the
combustion of gases or nuclear power plants
and only 1.3% is from renewable energies


A generator is a machine that turns
mechanical energy into electrical energy
It needs energy to turn wire coils in the
magnetic field of the permanent magnets.


Fossil fuel generating stations can use three
main types of fuel; Oil, coal and natural gas.
The gas is burned, and the chemical energy
released is used to heat water and produce
steam (1).
The high pressure steam is then used to turn
a set of fanlike wheels called turbines (2).


As the turbine wheels spin, they turn an
electromagnetic generator (3) that finally
produces electrical energy.
This electrical energy is then converted in a
transformer (4) to the correct voltage before
it is sent to people’s homes.
1.
2.
3.
4.
the fuel is burned to boil water to make
steam
the steam makes a turbine spin
the spinning turbine turns a generator
which produces electricity
the electricity goes to the transformers to
produce the correct voltage



Of the total electricity generation in Canada,
approximately 17% (107 million megawatt hours)
can be attributed to the combustion of coal and
oil.
Steam electric plants (boilers), combustion
turbines, and internal combustion engines
currently provide a generating capacity of 36,300
megawatts.
Coal-fired boilers account for 73% of this
capacity. Natural gas uses the same technique
but is much cleaner and produces 5% of Canada’s
energy, but its supply is limited.

Coal and oil-fired facilities account for the
majority of air emissions from the electric
power sector.
Emissions
-Carbon
dioxide
-Sulphur
dioxide
-Particulate
matter
Environmental issues due to
pollutants
-Toxic metals - Acid Rain
-mercury
- Smog
- Nitrous
oxides
- toxic substances
-Climate change


Of the total electricity generated in Canada,
approximately 15% (72 million megawatt hours)
is nuclear energy. Current nuclear generating
capacity is about 10,301 megawatts.
The process of nuclear generation is very similar
to that of fossil fuels. The basic difference is that
instead of chemical energy of fuel to heat water,
the energy used is from nuclear reactions.
Nuclear reactions occur when uranium atoms are
split by bombarding the atoms with neutrons.

The reaction is called nuclear fission and it
creates enormous amounts of heat which is
used to heat water that is converted into
steam which powers turbines. The turbines
then turn a generator which produces the
electricity
The use of nuclear power plants is
controversial. Below is a list of pros and cons
for the use of nuclear power.
Pros
-Low amounts of CO2
production
-Available to use now, it
does not need to be
developed
-Large amounts of power
from one plant
Cons
-Radio active waste
-Risk of accidents
-Limited supply of uranium
-takes 20 -30 years to build a
plant
-Heats up large amounts of
water


Of the total electricity generated in Canada,
approximately 60% (350 terawatt hours) is
from large-scale hydro power. Current hydro
generating capacity is approximately 65,000
megawatts.
A hydro electric power plant uses the energy
of falling water to turn a turbine. The turbine
is attached to a generator which sends the
power generated to a transformer which
converts the energy to a suitable voltage to
be send on the power lines.
Pros
-Renewable
-Low emission
Cons
- Destroys land animal habitat
- Destroys fish habitat
- Submerged vegetation emits
greenhouse gas.
- Mercury in rocks is released
into the food chain by bacteria
on the rotting vegetation.


Sources of green power are wind, solar, tidal,
geothermal, biogas-fuelled and biomass-fuelled
power sources. These sources have little or no
greenhouse gas emissions, and smog, acid-rain
or toxic pollution are zero.
While green power currently makes up only a
small percentage of Canada's electricity, Canada's
green power resource potential is enormous perhaps sufficient to account for up to half our
electricity needs, contributing to substantial
reductions of greenhouse gas and other air
pollutant emissions compared to conventional
fossil-fuelled generation. Growth of the industry
would also provide significant potential for
innovation, job creation and regional
diversification.

Wind power is created by using windmills.
The wind turns giant rotors that turn
electromagnetic generators. These generators
then send the power to transformers which
then convert the voltage to a useable amount
before it is sent into distribution. These can
now be seen popping up all over Canada.
Pros
Cons
-No
- Need wind
Pollution - Small amount of
energy produced
- Needs lots of space
- Kill birds

The sun is used to knock elections off atoms.
The electrons flow then creates a current
which must be converted into AC by an
inverter.
Pros
-No pollution
-Reliable
Cons
-Need a lot of light
-Small amount of
electricity
-Expensive

Methane produced from rotting garbage and
waste is burned. This is then used to heat
water and use the steam to turn a turbine to
create electricity.
Pros
Cons
-readily available -lots of energy lost
-Simple
-Pollution

With Geothermal, water is pumped
down into the earth where it is really
hot. The water turns into steam which
then rises to the surface and turns a
turbine which turns a generator and
creates electricity.
Pros
Cons
- No Fuel needed - Expensive
- Sustainable
- May cool down