Introduction: The Green Cube

The Green Cube is a portable renewable power generation cube like structure which harnesses electricity from solar cell,hand crancked generator and two small windmills.

The Best thing about The Green Cube is that it is portable and you can carry it around anywhere with you.It has two detachable windmills and a solar panel which can be kept in the cube itself making it the best choice to take the cube with you on picnics and holidays.

It has a separate USB output for solar cell,hand crancked generator and the windmills respectively.The best thing about this design is that even if there is a cloudy day outside you can still charge your phone or attach your usb bluetooth speakers or glow an led lamp just by rotating a handle at the back of the cube.

But what if you are tired and dont want to waste your enegy then the two windmills comes to your rescue.Just take them out of the cube and attach them on the side of the cube

The propellers roatate even if there is a light breeze thus making them useful even if it's not a windy day

And when the sun is out you can take out the solar panel,plug it in and charge your Gadgets.That simple!!

We all know that the human race is advancing rapidly,using all its fossil fuels at an exponential rate and I personally believe that the world needs to shift towards renewable energy and we have to transition away from fossil fuels very quickly!

Green cube is just a small step in attaining this goal and I hope it inspires other people to do their part in preserving our earth.

Step 1: What You Need:

Electronics Parts:

1)For solar charger circuit:

Solar Cell(5V or Greater)

1A LI-ion battery Charging Module x 1

DC-DC USB Boosting step up converter x 1

3.7V Lithium Ion Battery(2600 mah) x3

Round Female DC Power Jack x 1

1N4001 Diode x1


2)For wind Charger Circuit:

1A LI-ion battery Charging Module x 1

DC-DC USB Boosting step up converter x 1

3.7V Lithium Ion Battery(2600 mah) x2

Round Female DC Power Jack x 2

2.5mm Male DC Power Jack x 2

Three Blade Propellers x 2

1N4001 Diode x 2

DC Motor(5V) x 2


3)Hand Cranck Circuit:

1A LI-ion battery Charging Module x 1

DC-DC USB Boosting step up converter x 1

3-phase Motor x1 + Motor Mount For Motor x 1

Plastic Gear x1

Handle for rotating the motor

1N4001 Diode x 6

3.7V Lithium Ion Battery(2600 mah)


Tools Required:

Soldering iron

Glue gun


wire cutter


soldering wire

Electrical Tape

Step 2: Making the Enclosure:

The enclosure can either be made from acrylic sheets or you can 3d print it.for people who have access to 3d printing can 3d print the box or if 3d printing is not available then they can switch over to acrylic.

I made the enclosure using acrylic sheets as it was cheaper than 3d printing and also it gave a glossy Look.:-)

Step 3: Making the Solar Charging Circuit:

  • Take an unused phone charger and cut it from both ends with a wire cutter,after cutting you will get a long insulated wire.
  • Now take one end of the wire and split it into two peices and do the same for other end also.
  • After splitting you will see two wires,one black and one red(In most of the cases you will encounter these two colours only).
  • If you see other colour wires then there is no need to panic,I will be attaching an image with this step where you can see different wire colour configuration and their respective polarities.
  • Btw it dosen't matter what colour wire you use for wiring your solar panel,but its's a good habit to always check for polarities while dealing with electronics.
  • Now,the red wire is positive and the black wire is negative,so solder the wires to the appropriate tabs on the back of the solar panel
  • use electrical tape or use hot glue to cover the solder joints.
  • Now we have to attach the other end of the wire to the male dc jack
  • A male DC jack has a Tip and a Sleeve,connect the Positive red wire to the Tip and the Negative black wire to the Sleeve of the DC male Jack.

Step 4: Wiring Up DC Female Jack to the Charge Controller:

Li-ion charge controllers are very important to use if you are dealing with charging Li-ion batteries.I am using a TP4056 1A li-ion battery charging module.There are four solder points on it, two solder points In the front part of the charge controller next to the mini usb port.At these two points we hook up the Wires coming from the DC female power jack.

The other two solder spots are for the battery.


  • Take a DC female jack and connect the positive part of the 1N4001 diode to the positive leg of the female jack
  • Take a wire and solder it to the negative of the Diode(Negative part is that which has a silver line over it)
  • Take another wire and solder it to the negative leg of the Female jack.
  • Solder the wire from the negative leg of the female jack to the negative 'IN' point(IN-) on the board.
  • In the same fashion connect the wire from the negative of the diode to the positive 'IN' point(IN+) of the board.

Step 5: Making the Li-ion Battery Pack(3P Configuration):

Choosing a battery for your project can be a little bit confusing as they come with different sizes,capacities,voltages and prices.I was lucky enough to find an old laptop battery lying around my house,so it was not much of a trouble for me to get my hands on some li-ion cells.but still i had to make a battery pack from those individual 18650 cells.Now,if you dont have any li-ion cells then you can buy them cheaply from ebay or you can buy a li-po or li-ion battery if you want to save yourself from some work.

For this project we are going to be needing a 3.7 v battery having a capacity of can also use 4400mah or 2200 mah battery(as per your need).

so lets get started!!

In this step we will be making an li-ion battery pack using three 18650 li-ion cells each having a voltage of 3.7v and 2200 mah capacity.

Li-ion cells can be connected in series or in parallel,but we will prefer the latter because we need current more than the cells will be connected in 3p configuration(Three cells in parallel)..

so connecting 3 cells in parallel will give 3.7v and 6600 mah as output which is more than sufficient for your project.


  • Line all the cells in such a way that the positive terminals are on one side.
  • wrap all the three cells with electrical tape

  • Then carefully apply hot glue in between each cell.this will make the battery pack hold it's shape better.

  • After this solder all the positive terminals of the three cells together(As shown in the picture)

  • Follow the above step for Negative terminal too.

Step 6: Attaching the Charge Controller to the Battery:

  • Strip the wires coming from the battery pack.
  • Keep the two wires away from one another so that they dont get short.
  • Take a long black wire and twist it with the negative wire(yellow wire in the picture) from the battery.
  • Take another piece of wire(Red in colour) and twist it with the positive(red)wire coming from the battery.
  • Insert the twisted end of the negative wires through the negative solder point(BAT-) of the lithium charge controller and solder it into place.
  • Similarly,insert the twisted end of the positive wire through the positive solder point(BAT+) of the lithium charge controller and solder it into place.
  • Make sure that you solder the wires from the top
  • Cut off any extra bits of wire from underside of the charge controller.

Step 7: Attaching the Switch and the Usb Circuit:

  • In the previous step we connected the battery to the charge controller and we had two wires coming from the charge controller(Red and Black)
  • Solder The negative wire(black wire) coming from the charge controller to the Negative solder point of the usb circuit(IN-)
  • Cut the extra bits of wire from underside of the usb circuit
  • Now,Take the Positive wire coming from the charge controller(Red in colour) and solder it to the middle pin of the toggle switch
  • Take a piece of red wire and solder one end of it to the pin adjacent to the middle pin of the toggle switch(Btw it dosent matter which pin you choose to solder the wire but it has to be one from the remaining two pins)
  • Now take the other end of the wire and solder it to the Positive solder point of the usb Circuit(IN+).
  • Place the circuit inside the Box.


Step 8: Cranck It Up!

Now it's time to build the Hand cranck generator!!

Hand cranck generators have been there for a very long time now and they work on the principle of conversion of energy from mechanical to electrical.

It may directly use mechanical power from muscles, or a generator may convert energy generated by the body into electrical power.

Human-powered equipment describes electrical appliances which can be powered by electricity generated by human muscle power as an alternative to conventional sources of electricity such as primary batteries and the power grid. Such devices contain electrical generators or an induction system to recharge their batteries. Separate crank-operated generators are now available to recharge battery-powered portable electronic devices such as cell phones. Others, such as mechanically powered flashlights, have the generator integrated within the device itself. An alternative to rechargeable batteries for electricity storage is supercapacitors, now being used in some devices such as the mechanically powered flashlight. An early example of regular use of human-powered electrical equipment is in early telephone systems; current to ring the remote bell was provided by a subscriber cranking a handle on the telephone, which turned a small magneto generator. Human-powered devices are useful as emergency equipment, when natural disaster, war, or civil disturbance make regular power supplies unavailable. They have also been seen as economical for use in poor countries, where batteries may be expensive and mains power unreliable or unavailable. They are also an environmentally preferable alternative to the use of disposable batteries, which are wasteful source of energy and may introduceheavy metals into the environment. Communications is a common application for the relatively small amount of electric power that can be generated by a human turning a generator.

Survival radio:
The World War II-era "Gibson girl" survival radio used a hand-cranked generator to provide power; this avoided the unreliable performance of dry-cell batteries that might be stored for months before they were needed, although it had the drawback that the survivor had to be fit enough to turn the crank. Survival radios were invented and deployed by both sides during the war.The SCR-578 (and the similar post-war AN/CRT-3) survival radio transmitters carried by aircraft on over-water operations were given the nickname Gibson Girl because of their "hourglass" shape, which allowed them to be held stationary between the legs while the generator handle was turned.

Pedal-powered transmitter:The Pedal Radio (or Pedal Wireless) was a radio transmitter-receiver powered by a pedal-driven generator. It was developed by Alfred Traeger in 1929 as a way of providing radio communications to remote homesteads in the Australian outback. There were no mains or generator power available at the time and batteries to provide the power required would have been too expensive.

Step 9: Choosing the Motor:

Choosing a motor is always a tiresome task whether be it for any project.

you can either use a dc motor or an stepper motor for making your hand cranck generator.

In the beginning I planned on using a stepper motor but then i switched over to an 3 phase ac motor because the stepper motor i had was kind of heavy and the 3 phase motor which I salvaged from a hand cranck generator of some sort was lighweight and more efficient.

One thing about stepper motors and 3 phase motor is that you cannot just connect your circuit with the motor wires because the output of these types of motors is AC and we need DC for our devices or circuits to work

So in order to make it work we must add a bridge rectifier which basically is made up by using diodes(1N4007) and the output of the rectifier comes out to be DC.

Step 10: Making the Bridge Rectifier:

For Making a bridge rectifier you will be needing six 1N4007 diodes,one small perfboard and some wires.


  • Take a small perfboard(Mine was a little bit large bcz i had no small boards lying around at that time and i didn't wanted to cut it as it looks ugly after that!)
  • You can cut it to any size(Your choice,No pressure!).
  • Take two 1N4007 diodes and insert them in the perfboard as shown in the picture.
  • Now solder the negative and positive terminals together of the diodes as shown in the picture.
  • Again take two diodes and insert and solder them together just like in the previous step.
  • follow the above step again
  • Now,solder all the remaining negative terminals of the diodes together forming a negative rail.
  • Similarly solder all the remaining positive terminals of the diodes together forming a positive rail.
  • Now,take two lenghts of wire,one black and one Red.
  • Solder the black wire to the positive rail and solder the red wire to the negative rail.
  • These two wires is now our output of the motor.
  • After this solder all the 3 wires of the motor to input 1,input2 and input 3(refer picture)
  • You would have noticed that i have added some male header pins at various places on the circuit board.I only did that for testing purposes and you need not do that.

Step 11: Attaching the Charge Controller,usb Circuit and the Battery:

  • The steps involved are same as that of the solar charging circuit.
  • The minute difference is that in the solar charging circuit the input was from the solar panel while in this circuit the inputs are the two output wires coming from the bridge rectifier circuit.
  • In solar charging circuit we had the cells arranged in 3p configuration whereas in this circuit we have only one cell.
  • The rest of the circuit is same.

Step 12: Attaching the Hand Crancked Circuit:

Attach the motor inside the cube as shown in the picture

Insert the handle from the outside and the plastic gear from the inside

screw them together with the help of screws from inside.

After this the plastic gear and the handle are fitted in such a way that they get firmly attached with each other and get interlocked with the motor.

Now if we rotate the handle the motor roatate as well producing energy.

Step 13: Wind Power Generation:

Wind power is extracted from air flow using wind turbines or sails to produce electrical power. Windmills are used for their mechanical power.Wind power as an alternative to fossil fuels, is plentiful, renewable, widely distributed, clean, produces no greenhouse gas emissions during operation, and uses little land. The net effects on the environment are far less problematic than those of nonrenewable power sources.

Our next step will be wind power generation.For this we will have to construct two small windmills which can be mounted on the sides of our cube.

The design itself of these small windmills is quite interesting.

It uses channel mechanism which makes it very convenient to mount or unmount them from the cube.

Step 14: Design and 3D Print Files:

I designed all the parts used in this project using Autodesk Inventor,it was the first time i designed something on this and it's a great software to work with,best suited for designers and inventors.

All the design files and 3d print files are attached in this step.

Step 15: Attaching the Windmill:

Attaching the windmill on the cube is not a tough task

Just go through the pictures in this step and you will get an idea of it.:-)

Step 16: Making the Circuit:

Steps to make the circuit:

  • Take two female dc jacks
  • Solder the positive of the diode to the positive of the dc jack and solder a red wire to the negative of the diode,this acts as our positive wire.
  • solder a black wire to the negative of the dc jack,this will act as our negative wire.
  • Now,the propellers are designed in such a way that they spin anticlockwise when the wind blows so as a result the polarity of the motor reverses.
  • In earlier steps we assumed the tip of the dc male jack as the positive and the sleeve as the negative.
  • so one way of doing this is by soldering the positive of the motor with the sleeve of the dc male jack and soldering the negative of the motor to the tip of the jack.
  • so this way when the motor spins in anticlockwise direction the tip of the dc male jack will act as positive and the sleeve will act as negative.
  • Now,take a small perfboard and solder both the positive(red) wires coming from the two dc female jacks making a positive rail
  • similarly,solder the negative(black) wires from the two dc jacks making a negative rail.
  • Now take two lenghts of wire,one red and one black.
  • solder the red wire to the positive rail and solder the black wire to the negative rail.
  • The other end of these wire will act as our input.
  • Further,the circuit is made as shown in previous steps.

Step 17: Making the Partition and the Lid for the Box:

  • The lid or the cover for the cube can be constructed using acrylic sheet or you can use any other material but it shouldnt be fragile.
  • The purpose of partition in the cube is to make space for the solar panel and the two windmills,you can also keep a small led lamp or a small portable bluetooth usb speaker.
  • The main idea behind the partition was to make the cube portable,so that you dont have to carry the solar panel and the two windmills separately and you can keep them in the cube itself
  • I used thick foam as a support for the cardboard partition.

Step 18: Finish:

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