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 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 ElectricityPower plant generates electricity

Transformer steps up voltage for transmission

Transmission line carries electricity long distances.

Neighborhood transformer steps down voltage

Distribution line carries electricity to house

Transformer on pole steps down voltage before entering house

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/