Electricity Week 3. Solar Panel


Did you know that in just one hour the sunlight shining down on the earth could meet the world’s energy demand for an entire year? People have used the sun as a free and easily accessible heat source for thousands of years. For example, ancient Greeks built their homes to get the most sunlight during the cold winter months. In the modern world, solar energy is used for heating water for domestic use, space heating buildings, and generating electrical energy.

Photovoltaic devices, such as solar panels, are able to directly convert solar energy into electricity without consuming any fossil fuels. This operation is based on the photovoltaic effect; an observed occurrence of an electric current being produced when light energy strikes the surface of a certain semiconductor. A semiconductor is a substance with electrical properties, classified between a good conductor and a good insulator.

Photoelectric Process
(image source: https://bcachemistry.wordpress.com/2013/11/17/an-introduction-to-solar-panels-and-solar-energy/)

A semiconductor is a tricky matter to explain to grade-schoolers. However, no one said we have to teach it in scientific terms. If we think outside of the box, we may come up with a child-friendly story about athletic electrons on a circuit track. Let’s imagine a track where instead of a start line, there is a deep trench. The electron athletes all stand on one side of the trench, but to make it even more difficult, they are stuck in glue. The electron athletes become weak from trying to escape the glue and are soon unable to move at all. If only they had enough power to rip their shoes out of that glue and then jump over the trench, they would be free to run a lap. Upon return to the trench, they would see an empty, sticky spot left by another run-away electron athlete. Luckily for them a lightning bolt from the sky occasionally strikes one of the electron athletes, giving them enough power to take off, jump over the trench, and run a lap. When electrons run, we are talking about an electric current. This is how the energy from lightning bolts (or photons) is transformed into an electric current.

A good thing for parents or teachers to do before making up a metaphor of your own would be to first explore the adult-level explanation of the phenomena. Consider checking out these great resources:

Unlike homemade batteries and electromechanical generators, the solar cells are quite difficult to make at home with your child.

However, if you have enough patience and don’t mind a trip to the hardware store, you might want to make your own photovoltaic cell from scratch. Check out this post on scitoys.com.


‘Solar Cockroach 2.0’ is another great DIY project kids would love working on. The list of supplies, tools, and instructions are available at instructables.com.

If you don’t like the idea of soldering or messing with hot glue, go ahead and check out these educational solar panel kits you can easily buy online.

ipad_black copy

Whichever DIY solar panel project you choose, it is always a great idea to supplement the exploration experience with interactive virtual models. Check out the solar panel lab in our app ‘How to Make Electricity‘. There you can discover the effects weather conditions, bird droppings, and other circumstances have on the efficiency of the solar panel.


Download the ‘How to Make Electricity‘ app from the App Store.
Download free lite version of the ‘How to Make Electricity’ app.

Mom’s Choice Awards – Mobile Apps Gold for Charlie


Charlie Jumped out of the Clock Gold MCA

Our app ‘Charlie Jumped out of the Clock‘ has become a winner of Mobile Apps Gold – Mom’s Choice Awards® (MCA). The Mom’s Choice Awards Honoring Excellence seal is widely recognized as the symbol representing the best in family-friendly media, products, and services.

Gold Award Recipient

Charlie Jumped out of the Clock‘ is a beautiful and heartwarming storybook app that teaches children all there is to know about telling time. Following Grandpa throughout his day, little readers learn to set the clock to specific times so Grandpa doesn’t miss his daily chores.

Check out great reviews Charlie has got so far.

– AppyMall

– Best Apps for Kids

– The iMums

– Best Apps for Kids

Download the ‘Charlie Jumped out of the Clock’ app.

appstoreBadge 2

Get the free light version here.

DIY Charlie Clock

Crayon Box Electricity Art PDF DownloadTeach your child to tell time with these cute DIY clock inspired by our Charlie Jumped out of the Clock app. The template pdf file includes three sets for different learning stages.
– color printer
– multi-purpose office paper (A4 size)
– cardboard paper (A4 size)
– brass fastener
– scissors
– awl
Steps for making each type of clock can be found in the template pdf.

Download the ‘Charlie Jumped out of the Clock’ app.

appstoreBadge 2

Get the free light version here.

Electricity Week 2. Generator


Nearly all of the electric power on Earth is generated at power stations by electromechanical generators.

An electric generator* is a machine that converts mechanical energy to electricity.
*Note: a generator itself does not produce electric power.

The primary components of all generators are magnets and wire coils. Every generator works on the basis of electromagnetic phenomena associated with the relationships between electricity and magnetism. An electric current produces a magnetic field, and vice versa.

1820 – Danish scientist Hans Christian Ørsted (pronounced “ersted”) discovered that electric currents create magnetic fields.
1824 – British scientist William Sturgeon invented the electromagnet.

An observation of these cause-and-effect relationships helps us to understand how electromechanical generators work. The best way to introduce children to the idea of electromagnetic phenomena is to do a series of experiments. The goal is to recreate the path of discovery scientists took while exploring electromagnetism in the first half of the 19th century.

Let’s try making our own electromagnet!


Materials needed:

– large iron nail
– thin coated (insulated) copper wire
– dry cell battery
– electrical tape
– paper clips (or other magnetic items)
– wire strippers
Image source: www.youtube.com/watch?v=PwVuLK0Q-po

Image source: www.youtube.com/watch?v=PwVuLK0Q-po


1) Wrap the wire around the nail, leaving at least 10 inches of wire at the end. (Note: don’t overlap the wire when you wrap it)
2) Once the nail is wrapped, cut the wire, leaving about 8 to 10 inches on that end too.
3) Peel the insulation off both ends of the copper wire.
4) Attach one end of the wire to the positive terminal, and the other end to the negative terminal of the battery. Tape both ends to the battery terminals to keep them in place.
5) Test your electromagnet on paper clips or other magnetic items.

Discussion points:

1) The electric current running through the wire generates a magnetic field. We can observe this by the effect it has on the paper clips.
2) However, the magnetic field created by the electromagnet is temporary. It exists only as long as there is electricity running through the wire. Try disconnecting one end of the wire from the battery to see how the electromagnet loses its magnetism.

Beginning in 1830, US scientist Joseph Henry systematically improved and popularized the electromagnet.

You too can make your electromagnet more efficient by:

1) Increasing the number of wire turns
2) Using a battery that can provide a higher current
3) Choosing a bigger nail

Warning! Be careful, too much current can be dangerous because of the heat generated.


After the invention of electromagnet, English scientist Michael Faraday theorized that if it was possible to make a non-magnetic object (the iron nail in our case) magnetized by adding electricity, then it should also be possible to generate electricity using magnets.

Let’s discover this possibility for ourselves by making our own simple generator similar to the one invented by Faraday back in 1831.

Materials needed:

– coated copper (or other magnetic wire) 40-60 feet, or 15 m long
– strong bar magnet
– hollow tube (paper towel cardboard cylinder)
– voltmeter or multimeter
– tape
– wire strippers
Image credit: sciencewithkids.com

Image credit: sciencewithkids.com


1) Leaving approximately 6″ of wire slack, start wrapping the wire around the tube. Keep wrapping until about 6″ of wire remains.
2) Secure its ends using tape.
3) Peel the insulation off both ends of the wire, and attach them to a multimeter or voltmeter.
4) Set the voltmeter (or multimeter) to test for DC voltage, and make sure it’s set for the lower voltage unit.
5) Place the magnet inside the tube and move it quickly back and forth. If it helps, tape the magnet to a rod.
6) As you move the magnet, observe the voltmeter voltage readings.
7) Set the voltmeter to test for DC current and repeat the observation while moving the magnet quickly back and forth inside the tube.

Discussion points:

1) The magnet affects electrons inside the wire. Its magnetic field makes them move by pushing and pulling them. If the magnet inside the tube does not move, neither do the electrons inside the coil.
2) When you move the magnet back and forth or spin it, the magnetic field near the wire also changes. The changing magnetic field produces an electric current by making electrons in the wire move. This phenomenon is called Faraday’s law of electromagnetic induction. The majority of electric generators operate on the basis of Faraday’s law.

We can build a more efficient generator by:

1) Choosing a stronger rare-earth magnet
2) Choosing a slightly thicker gauge magnet wire
3) Finding a way to move the magnet quicker*

*If we had a powerful mechanical force moving the magnet, then that would generate more electricity. For example, we could attach the magnet to a group of gears and rotate it at a higher speed.

To generate electricity for big cities, powerful jets of steam are used to rotate shafts of gigantic generators comprised of complex arrangements of magnets and coiled wires. Where do they get the steam? The steam comes from thermal power stations. Burning various types of fuel, such as coal or gas, is used to boil a vast amount of water. At hydro power stations the force of falling water rotates generator shafts.


Crayon Box How to Make Electricity Science View

Labs 2 and 3, of the How to Make Electricity app, allow kids to build simple interactive prototypes of hydroelectric and thermal power plants. Children are offered three types of coils to choose from. The goal is to figure out the most efficient way to rotate the magnet. The magnetic field and the effect it has on electrons are visible in the science view mode. Implementing visual aids does a tremendous job helping further a child’s understanding of the nature of electromagnetic phenomena explained by Faraday’s law.

Crayon Box How to Make Electricity - Generator


Download the ‘How to Make Electricity‘ app from the App Store.
Download free lite version of the ‘How to Make Electricity’ app.

Electricity Week 1. Batteries

Crayon Box Electricity Week 1 Battery

Everyday we use various types of batteries without knowing much about how they work. Our very first ‘Electricity Week’ is dedicated to the simplest kind of battery – the voltaic cell. We start off with a scientific explanation and then move on to the experiment portion, where we describe fun and engaging projects you can do with your kids.


A simple battery is comprised of three parts: two electrodes made of different metals, and an electrolyte (usually a liquid) that reacts with them.

Simple battery makeup

Simple galvanic cell makeup


“The battery generates current when one electrode (the anode) dissolves more easily in the electrolyte than the other electrode (the cathode). The dissolved atoms enter the electrolyte as positive ions, leaving some excess electrons behind on the anode. When a wire is connected between the anode and the cathode, the excess electrons redistribute themselves and some of them flow through the wire to the cathode, thereby producing an electric current.”

Battery Basics, sciphile.org

Now, how can you explain this to a 5-year-old? Assuming that your child already knows the story about electrons that live inside wires, you can explain the reason why these tiny guys want to travel from one electrode to another. Due to a chemical reaction, one electrode (the anode) becomes the birthplace of new electrons. At the same time, another electrode (the cathode) becomes a highly attractive place for the electrons to reside. A wire connecting the electrodes works as a path for the electrons. When electrons pass through the wire, we call that an electric current.

The idea of electrons traveling in search of a better place can be expanded further to explain other characteristics of batteries, such as voltage, current, and capacity. However, making up a good child-friendly story takes some serious preparation. Check out this great article about batteries.


The voltage of the battery depends solely on the chemistry between the electrodes and the electrolyte. This means different materials will provide different levels of voltage. The highest voltage is achieved when: 1) the anode is strongly reactive with the electrolyte, and 2) the cathode has the weakest reactivity with the electrolyte it is immersed in.

Which materials can be used for homemade batteries? For the electrodes you can use zinc, aluminum, copper or steel. Weak acids (e.g. citric, acetic, or phosphoric) or a salt-water solution can be suitable for the electrolyte. Zinc is the best anode material. Copper and stainless steel both make good cathodes.


Sources for common electrodes



The highest voltage (about 1.2 volts) can be achieved with zinc, stainless steel and phosphoric acid.

The maximum available current is difficult to predict because it depends on various parameters, such as the size and proximity of electrodes, as well as the concentration of the electrolyte. In order to get higher currents, use larger electrodes, placed closer to each other, immersed into a more concentrated electrolyte.

Lastly, the capacity of the battery depends on its size. Larger sizes of electrodes and larger volumes and concentrations of electrolytes last longer.


DIY battery projects isn’t just fun for kids. Set a goal to make the most efficient battery in terms of: 1) highest voltage, 2) highest current, or 3) highest capacity.

Check out these common types of homemade batteries and learn how to make them.


Anode: a strip of aluminum from a soda can.
Cathode: a piece of thick copper grounding wire.
Electrolyte: Coke or any other soda.
Voltage: approximately 0.75 volts.
Max current: about 3 mA.

Coke can battery

Battery made using a strip of aluminum from a soft drink can, a piece of copper grounding wire, and a glass of Coke. Produces 0.75 volts and a maximum of about 3 mA. Credit

More about coke can batteries:


Anode: a zinc washer.
Cathode: a copper penny.
Electrolyte: Coke or any other soda.
Voltage: approximately 1.0 volts.

Three lemon batteries connected in series with an LED. Each battery uses a zinc washer for the anode and a penny for the cathode. Together, the three batteries produce a little over 2.5 volts and maximum of about 0.1 mA.

Three lemon batteries connected in series with an LED. Each battery uses a zinc washer for the anode and a penny for the cathode. Together, the three batteries produce a little over 2.5 volts and maximum of about 0.1 mA. Credit

More about lemon batteries:


Anode: a zinc washer.
Cathode: a copper penny.
Electrolyte: vinegar.
Voltage: approximately 0.5 volts.

Soak a piece of paper or cardboard in vinegar and sandwich between a penny and a zinc washer to create battery. Stacking many of these battery cells in series, one on top of the other, creates a “voltaic pile”.

Voltaic pile made from a stack of pennies, zinc washers and vinegar-soaked paper stickers. The stack is housed in a plastic coin tube of the type used by coin collectors. Twenty cells are stacked to produce 15 volts and a maximum current of about 0.2 mA.

Voltaic pile made from a stack of pennies, zinc washers and vinegar-soaked paper stickers. The stack is housed in a plastic coin tube of the type used by coin collectors. Twenty cells are stacked to produce 15 volts and a maximum current of about 0.2 mA. Credit

More about penny battery:

Some items you can connect to your battery include: LEDs, low power light bulbs, and calculators. Digital multimeters can be used to measure voltage and current.


How to Make Electricity is a virtual lab where kids can get their hands on various experiments on generating electricity.

Our app ‘How to Make Electricity’ is a virtual lab where kids can get their hands on various experiments to generate electricity. The app features a set of adapted, child-friendly, interactive physical models. If a real coke can battery can light up only a tiny LED, the voltaic cell in lab #1 of our app can make a pickle glow.


Download the ‘How to Make Electricity‘ app from the App Store.
Download free lite version of the ‘How to Make Electricity’ app.