Electricity and Hydrogen Energy Carriers PLTW Gateway Unit 3 – Lesson 3.2 – Solving the Energy Crisis Energy Carriers Electricity and Hydrogen Gateway – Energy and the Environment © 2011 Project Lead The Way, Inc.

Energy Carriers PLTW Gateway Unit 3 – Lesson 3.2 – Solving the Energy Crisis 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? Energy Carriers PLTW Gateway Unit 3 – Lesson 3.2 – Solving the Energy Crisis 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 If students have already completed the Magic of Electrons™ unit, remind them of the motor and generator that they made in that unit. You might also remind students of the Electromagnet they used in the Automation and Robotics™ unit. If not, you may want to spend more time on electromagnetism – see the Magic of Electrons™ unit. Magnetism and electricity are related. Magnets can create electricity and electricity can produce magnetic fields. Every time a magnetic field changes, an electric field is created. Every time an electric field changes, a magnetic field is created. Magnetism and electricity are always linked together; you can’t have one without the other.

Electricity from Turbines Energy Carriers PLTW Gateway Unit 3 – Lesson 3.2 – Solving the Energy Crisis 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 Energy Carriers PLTW Gateway Unit 3 – Lesson 3.2 – Solving the Energy Crisis 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? Energy Carriers PLTW Gateway Unit 3 – Lesson 3.2 – Solving the Energy Crisis 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 Energy Carriers PLTW Gateway Unit 3 – Lesson 3.2 – Solving the Energy Crisis Transporting Electricity Power plant generates electricity Transformer steps up voltage for transmission Transmission line carries electricity long distances. Transformer on pole steps down voltage before entering house Distribution line carries electricity to house Neighborhood transformer steps down voltage

Transporting Electricity Energy Carriers PLTW Gateway Unit 3 – Lesson 3.2 – Solving the Energy Crisis Transporting Electricity Electricity moves through a complex transmission system. Transformers are located in substations near the electric generating plant. In much the same way that a pump builds up the pressure of water in a hose, transformers step up the electricity voltage to levels ranging from 69,000 to 765,000 volts. The voltage levels depend on the distance the electricity must travel and the amount desired. From the transformers, electricity enters the transmission system. Large lines on towers carry electricity in much the same way that long hoses carry water under great pressure. The transmission lines, which consist of heavy cables strung between tall towers, carry power to the point where it is needed. Electricity travels at nearly the speed of light, arriving at a destination at almost the same moment it is produced. Step-down transformers located in distribution substations reduce the voltage of the electricity to lower levels so it can be carried on smaller cables or distribution lines. Smaller transformers on poles or underground further reduce the voltage so that it can be used by residential customers. Homes and farms require 120 or 240 volt service. Industrial customers using large amounts of power ordinarily require higher service voltages. http://www.mnpower.com/about_electricity/

The Future of Electricity Energy Carriers PLTW Gateway Unit 3 – Lesson 3.2 – Solving the Energy Crisis 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 Energy Carriers PLTW Gateway Unit 3 – Lesson 3.2 – Solving the Energy Crisis 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 gas is lighter than air and, as a result, it rises in the atmosphere. This is why hydrogen as a gas (H2) is not found by itself on earth. It is found only in compound form with other elements. Hydrogen combined with oxygen is water (H2 O). Hydrogen combined with carbon forms different compounds such as methane (C H4), coal, and petroleum. Hydrogen is also found in all growing things—biomass. It is an abundant element in the earth's crust. Since hydrogen doesn't exist on earth as a gas, we must separate it from other elements. We can separate hydrogen atoms from water, biomass, or natural gas molecules. Hydrogen can be produced at large central facilities or at small plants for local use. Every region of the country (and the world) has some resource that can be used to make hydrogen. Its flexibility is one of its main advantages.

Hydrogen Uses of Hydrogen Energy Carriers PLTW Gateway Unit 3 – Lesson 3.2 – Solving the Energy Crisis 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? Energy Carriers PLTW Gateway Unit 3 – Lesson 3.2 – Solving the Energy Crisis 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. Because of the high cost to build fuel cells, large hydrogen power plants won't be built for a while. Today, there are an estimated 500 hydrogen-fueled vehicles in the U.S., mostly in California. Most of these vehicles are buses and automobiles powered by electric motors. They store hydrogen gas or liquid on board and convert the hydrogen into electricity for the motor using a fuel cell. Only a few of these vehicles burn the hydrogen directly (producing almost no pollution). The present cost of fuel cell vehicles greatly exceeds that of conventional vehicles in large part due to the expense of producing fuel cells.

Energy Carriers PLTW Gateway Unit 3 – Lesson 3.2 – Solving the Energy Crisis 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

Energy Carriers PLTW Gateway Unit 3 – Lesson 3.2 – Solving the Energy Crisis 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/