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STUDENT GUIDE
Renewable Energy Activity
UNIT 1
ENERGY STORAGE ACTIVITY
Copyright © All Rights Reserved to Horizon Educational Group
www.horizoncurriculum.com
STUDENT GUIDE
Energy Storage Activity
UNIT 1
Objective:Experiment with batteries and fuel cells to determine the advantages and disadvantages of each.
Background:It is easy to get energy for an object that does not have to move. The method of supplying that energy can be as large or as heavy as we like, because we do not have to take it anywhere. However, if we need power on the go, our options become much more limited.
Cars have traditionally overcome this by using an internal combustion engine, which provides power by burning gasoline. The fuel can easily be refilled, but when it is burned emits pollution in the form of exhaust. Non-polluting alternatives that have the mobility of the internal combustion engine but do not produce harmful exhaust have been developed in recent time.
Fuel cells are similar to the internal combustion engine because they also require a fuel that gets used up and can be easily refilled. Unlike the internal combustion engine, however, the only exhaust they produce is water vapor.
Just like an internal combustion engine, a fuel cell needs a place to store its fuel to be able to provide energy while moving. In the case of hydrogen fuel cells, the hydrogen gas presents a problem because of its very low density. This means that the hydrogen must somehow be pressurized or compacted, otherwise issues such as the fuel tanks being too large or the range of the vehicle being too short will occur.
One way to address that limitation is with metal hydrides, solid forms of hydrogen storage that chemically bond the hydrogen atoms to special metal alloys, allowing for large amounts of hydrogen to be stored in a small space.
Though much of the hydrogen used in fuel cells today comes from fossil fuel sources, it is possible to generate hydrogen from water as well. Using solar or wind power to provide the energy necessary to separate hydrogen from the oxygen in water makes fuel cells a completely pollution-free energy solution.
Batteries rely on chemical reactions to provide an electric current, which can then be used to drive a motor. Since they do not produce any exhaust, they are non-polluting. Unfortunately, their chemistry means that it is difficult to refill their energy reserves quickly; thus they require significant amounts of time to charge.
One way to store electrical energy directly, without the chemical reactions of a battery, is through a device called a supercapacitor. Supercapacitors rely on the movement of electrons to store their energy; unlike batteries they can be quickly charged. Similar to batteries, however, their energy can be released simply by connecting them to an electric circuit.
Batteries, supercapacitors, and fuel cells all produce electricity without emitting pollution, but which is really the “greenest” energy source? We will run experiments with each of them to find out which would be the best source of clean energy storage.
Energy Storage
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www.horizoncurriculum.com
STUDENT GUIDE
Energy Storage Activity
UNIT 1
Fuel Cell Procedure:You will need the following materials to assemble the fuel cell: red and black wires, fuel cell, battery pack, H2 and O2 cylinders, two lengths of tubing, and a syringe.
1. Insert the cylinders into the frame of the car. Fill them with 40 mL of distilled water.2. Uncap the tube on the O2 side of the fuel cell.3. Fill the syringe with distilled water. Fill the fuel cell with the water using the syringe.4. Replace the cap on the O2 tube.5. Insert the fuel cell into the frame of the car in front of the cylinders. Attach the H2 and O2 sides of the fuel
cell to the H2 and O2 cylinders with the longer tubes, which will prevent the hydrogen and oxygen gases from escaping.
6. Connect the battery pack to the fuel cell using the red and black plugs, then turn on the battery pack. You should see the fuel cell start to generate hydrogen and oxygen gas.
7. Once you see bubbles start to escape the H2 cylinder, turn off and disconnect the battery pack.8. Connect the loose red and black wires to the fan or LEDs to start generating electricity.9. Use the stopwatch to time how long the fuel cell powers the fan or LEDs. Record your results below.
Trial: Time (s):123
Supercapacitor Procedure:You will need the following materials to use the supercapacitor: red and black wires, the capacitor, potentiometer, and the hand-crank generator.
1. Connect the capacitor to the potentiometer using one set of red and black wires. 2. Connect the hand-crank generator to the potentiometer using another set of black wires.3. Turn the hand-crank clockwise to generate current and keep turning until the capacitor is full according to
the gauge on the potentiometer.4. Disconnect the potentiometer from the capacitor and connect the capacitor to the fan or LEDs. 5. Use a stopwatch to time how long the capacitor can run the fan or LEDs. Record your results below.
Trial: Time (s):123
Copyright © All Rights Reserved to Horizon Educational Group
www.horizoncurriculum.com
STUDENT GUIDE
Energy Storage Activity
UNIT 1
Salt Water Battery Procedure:You will need the following materials to assemble the salt water battery: red and black wires, the salt water battery (white bottom and blue top), syringe, and a graduated cylinder.
1. Collect salt water solution from your teacher and put it in the graduated cylinder. Make sure to get at least 25mL of the solution. Be careful; it is hot!
2. Using the syringe, transfer 15mL of the salt water solution into the bottom of the battery.3. Snap the blue top of the battery onto the white bottom.4. Attach one red wire to the two red plugs on the left and right sides of the battery at the back.5. Attach the loose red and black wires to the fan or LEDs to start generating electricity. 6. Use the stopwatch to time how long your battery powers the fan or LEDs. Record your results below.7. When you are finished with the salt water battery, rinse the top and bottom with distilled water.
Trial: Time (s):123
Hydrostik Procedure:You will need the following materials to assemble the hydrostik generator: red and black wires, mini fuel cell, silicon tubing, clamp, hydrostik, and the pressure regulator.
1. Push the silicon tubing through the clamp until the clamp is halfway along the tubing.2. Attach one end of the tube to the bolt of the pressure regulator.3. Screw in the pressure regulator to the top of the hydrostik.4. Attach the opposite end of the tube to the nozzle of the mini fuel cell.5. Place the fuel cell in the frame of the car with the nozzles facing forward.6. Use the loose red and black wires to connect the red and black plugs on the fuel cell to the other red and
black plugs on the front of the frame.7. Open the clamp and press the purge valve for two seconds on the fuel cell. This will allow hydrogen to enter
the fuel cell and cause the car to start running.8. Connect the fuel cell to the fan or LEDs to start producing electricity. 9. When the hydrostik is empty, use the Hydrofill Pro to refill it.
Copyright © All Rights Reserved to Horizon Educational Group
www.horizoncurriculum.com
STUDENT GUIDE
Energy Storage Activity
UNIT 1
Measurement Procedure:1. Choose one of the electricity generation methods you explored in the previous sections. 2. Assemble your chosen generation method as described previously.3. Connect the Horizon Renewable Energy Monitor to your circuit with another set of red and black wires. 4. Run your generator as described previously and measure the current (mA) and voltage (mV) produced.
Record your results below.5. Choose a new generation method and repeat Steps 2 through 4. 6. Lastly, try attaching the battery pack directly to the fan or LED through the Renewable Energy Monitor and
record the results below.
Trial: Generator: Current (mA) Voltage (mV)12345 Battery Pack
Analysis:1. Does the data from your measurements match with the data from the fan or LEDs? In other words, does
the generation method that lasted the longest also produce the most electric current? Explain what you observed.
2. Which of the sources you tested produced the most electricity? Why do you think it produced the most?
3. What limited how long each of your generators could run and what could increase that time?
