Transcript Energy Carriers - mygatewaytotechnologyclass

Energy Carriers
Electricity and Hydrogen
Energy Carriers
Energy carriers move energy in a usable
form from one place to another.
Electricity  Most well-known energy carrier
Hydrogen  Not yet widely used, but has
great potential for the future
Where Does Electricity
Come From?
• Magnets
– Electromagnetism is
magnetism created by a
current of electricity
– A magnetic field can move
electrons
• Batteries
– Produce moving electrons
through a chemical reaction
Electricity from Turbines
• Power plants use huge turbine
generators to make electricity
• Fuels to spin turbines include
– Wind
– Burning coal, oil,
or natural gas to
make steam
– Split uranium atoms
can heat water into
steam
– Power of rushing water from a dam
Electricity from Batteries
• A battery has a + terminal and a – terminal.
• Electrons collect on the negative terminal.
• Connect a load, like a light or motor, with
wires to the battery.
• A chemical reaction
in the battery forces
the electrons to flow
from the battery into
off
on
the wire.
Is Electricity Exhaustible or
Inexhaustible?
• Neither; electricity is a secondary source
of energy.
• Electricity is produced by burning coal, oil,
or natural gas – all exhaustible resources.
• Electricity is also produced with hydro,
wind, and solar power – all inexhaustible
resources.
Transporting Electricity
Power plant
generates
electricity
Transformer Transmission
steps up voltage
line carries
for transmission
electricity
long
distances.
Transformer
on pole steps
down voltage
before
Distribution
line
Neighborhood
entering
carries electricity
transformer
to househouse
steps down
voltage
Transporting Electricity
The Future of Electricity
• Electricity cannot easily be stored. It must
be generated and delivered at the precise
moment it is needed.
• Electricity travels down whatever paths are
made available, but cannot be directed to
a certain location.
• Electricity can be made from inexhaustible
and renewable energy sources.
• Engineering researchers are searching for
ways to efficiently store electricity and
deliver it when and where it is needed.
Another Option –
Hydrogen
• Hydrogen is the most abundant gas in the
universe, but it does not exist naturally on Earth.
• How is hydrogen made?
– Steam reforming separates hydrogen atoms from
carbon atoms in methane (CH4)
• Advantage – least expensive
• Disadvantage – methane is a fossil fuel, so greenhouse
gases are emitted
– Electrolysis splits hydrogen from water
• Advantage – no emissions
• Disadvantage – very expensive
Hydrogen
Uses of Hydrogen
– Industry  refining metals and processing food
– NASA  energy fuel
• Hydrogen batteries power electrical systems; the
only by-product is pure water, which the crew drinks
– Fuel Cells
•
•
•
•
Emergency power for hospitals
Longer power for laptops and cell phones
Military
Vehicles
Why Hydrogen?
• Hydrogen is everywhere. It is the most abundant
element in the universe.
• Hydrogen can be made from renewable resources.
• Hydrogen fuel cells produce no emissions.
• Hydrogen is efficient, emits little pollution, and can
be used for transportation, heating, and power
generation.
Future of Hydrogen
• Great potential as an
environmentally clean
energy fuel
• Great potential to reduce
our reliance on imported
energy sources
BUT . . .
• Facilities to make, store,
and move hydrogen must be
built
• Fuel cells must become
more affordable
• Consumers need
technology and education
to safely use hydrogen
Image Resources
Microsoft, Inc. (2009). Clip art. Retrieved April 10, 2009, from
http://office.microsoft.com/en-us/clipart/default.aspx
National Energy Education Development Project (NEED). (2009).
Retrieved April 10, 2009, from
http://www.need.org/needpdf/NEED_ChangeTheWorld_2008.pdf
Minnesota Power. (2009). Retrieved April 10, 2009, from
http://www.mnpower.com/about_electricity/