Download Energy Carriers Electricity and Hydrogen

Energy Carriers
Electricity and Hydrogen
EPIT
C. Ned Rogers
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
the wire.
off
on
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 byproduct 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