Commercial solar panels are becoming increasingly popular in recent times mainly because of increasing awareness on how to live a sustainable lifestyle, its advantages and disadvantages.
Sustainable and eco-friendly lifestyle will encourage individuals, industries, and government agencies, to reduce the amount green house gases generated by the use of fossil fuels, keep the environment free from pollution, protect wildlife, save cost on energy bills and use renewable energy sources.
One of such sources of renewable energy is the solar energy. Tapping energy from the sun has been a long age desire of humans starting as early as the 16th century.
It was not until 1884 that Charles Fritts was able to build a solar panel system that was mounted on New York city roof tops.
The combination works by converting light coming from the sun into electricity by means of the photovoltaic effect. The converted electricity can be stored in a battery, converted into alternating current by means of an inverter; suitable for domestic purposes.
The advantages using solar power for home use are numerous to mention.
- They are renewable energy source,
- They have low maintenance cost,
- They are affordable if you can take care of the one-time high cost,
- They will offset your electricity bills,
- Direct sunlight is not necessary,
- It is an evolving technology with s much development to be hopeful for,
- It will reduce your carbon foot print.
We will learn how to build a solar panel system from scratch to finish using solar cells and other affordable materials. You will know if you have what it take to build your own solar panel as well as the cost of building a solar panel system.
To build your own solar panel, you’ll need to:
- assemble the solar cell pieces,
- connect the cells,
- build a panel box,
- wire the panels,
- seal the box, and then finally mount your completed solar panel.
- 1 How does the solar panel work
- 2 Types of solar panels
- 3 Is it possible to build a solar panel system?
- 4 Materials needed to build a solar panel
- 5 Step by step guide on how to build a solar panel
- 5.1 1. Prepare your working table and tools.
- 5.2 2. Measure, Outline and Cut the Backing board
- 5.3 3. Measure and Cut the tab wire
- 5.4 4. Connect the individual cells in series to get the desired voltage.
- 5.5 5. Link the connected cells with the bus wire
- 5.6 6. Measure the output voltage
- 5.7 7. Build the casing for the panels
- 5.8 8. Connect the terminals of the solar panel
- 5.9 9. Seal off any Leakages
- 5.10 10. Mount your solar panel
- 6 Conclusion
How does the solar panel work
When the sun hits the surface of solar panels, it induces a chemical and physical reaction within the solar cells by means of photons, which knocks off free electrons from the atoms (components that make up the photovoltaic cell), thereby generating a flow of electricity.
Photons are light particles. The process of separating electrons from their atoms creates solar electricity. This electricity is direct current (DC) electricity which is converted into alternating current (AC) using power inverters, making it suitable for use in our appliances.
Solar panels actually comprise many, smaller units called photovoltaic cells which are linked together to make up the panel.
Each photovoltaic cell is made up of two slices of semi-conducting material, usually silicon, which is same material used in most electronic appliances.
Mode of Operation of Photovoltaic Cells
In order to work, photovoltaic cells are made to establish an electric field which occurs when opposite charges are separated.
To get this field, manufacturers add impurities like phosphorus and boron to silicon by a process called doping. This gives each side of the silicon slice a positive or negative electrical charge.
Specifically, they seed phosphorous into the top layer of silicon, which adds extra electrons with a negative charge to that layer, while the bottom layer gets a dose of boron, which results in fewer electrons, or a positive charge.
This builds up to an electric field at the junction between the silicon layers. Then, when a photon of sunlight knocks an electron free, the electric field will push that electron out of the silicon junction.
Other components of the photovoltaic cell converts these “knocked off” electrons into usable power. There is also a metal conductive plates on the sides of the cell that collects the electrons and transfer them to wires. At that point, the electrons can flow like any other source of electricity (Direct Current Electricity)
The solar cell or photovoltaic cells are then connected piece by piece to form a solar array, that is called the solar panel.
Types of solar panels
Solar panels can be of different types which are dependent on how they’re made, appearance, performance, costs, and the installation method.
Three solar panel types exists;
Monocrystalline or single-crystalline solar panels are made using the Czochralski method. They are created from a single continuous crystal structure.
In this method, the silicon crystal ‘seed’ is placed in a vat of molten silicon. The seed is then slowly drawn up with the molten silicon forming a solid crystal structure around the seed, called an ‘ingot’.
The ingot of solid crystal silicon that is formed is then finely sliced into what is known as a silicon wafer. This is then made into a cell.
The Czochralski process results in large cylindrical ingots. Four sides are cut out of the ingots to make silicon wafers. A significant amount of the original silicon ends up as waste.
Monocrystalline solar panels have an efficiency rate of between 15 to 20%. They are the most efficient types of solar panels because their crystal framework is even. Physically, they appear as grid-like structures.
This is a newer technology than the monocrystalline solar panel types.
To build a polycrystalline solar panel, a silicon crystal ‘seed’ is placed in a vat of molten silicon just like the monocrystalline structures.
However, rather than draw the silicon crystal seed up, the vat of silicon is simply allowed to cool.This method allows the formation of distinctive edges and grains in the solar cell.
A major physical difference between a polycrystalline and a monocrystalline solar panel is that polycrystalline are rectangular with no rounded edges. Due to the imperfect crystal structure of their cell, they have a grainy bluish coating appearance.
The polycrystalline panels are less efficient than the monocrystalline panels but more efficient than other types of panels. They have an efficiency rate of between 13 and 16%.
Polycrystalline are now very close to Monocrystalline cells in terms of efficiency.
Polycrystalline cells, with continued quality improvements, have helped push the standard 60-cell polycrystalline panels from 240W to 300W over the last five years.
3) Thin-film Solar Panels
Recently, researchers have produced ultrathin, flexible solar cells that are only 1.3 microns thick — about 1/100th the width of a human hair and 20 times lighter than a sheet of office paper.
In fact, the cells are so light that they can sit on top of a soap bubble, and yet they produce energy with about as much efficiency as glass-based solar cells, scientists reported in a study published in 2016 in the journal Organic Electronics.
Lighter, more flexible solar cells such as these could be integrated into architecture, aerospace technology, or even wearable electronics.
Thin film panels are made out of a different type of silicon, known as amorphous silicon (a-Si) and sometimes other materials with semiconductor properties known as CIGS (copper indium gallium selenide solar cells).
A thin film panel can be identified as having a solid black appearance without the normal cell outlines you see on the face of a crystalline panel.
They are made by depositing a photovoltaic substance onto a solid surface like glass. The photovoltaic substance that is used varies and multiple combinations of substances have been successfully used commercially.
Examples of the most common photovoltaic substances used include:
- Amorphous silicon
- Cadmium Telluride (CdTe)
- Copper indium gallium selenide (CGIS)
- Dye-sensitized solar cell (DSC)
Is it possible to build a solar panel system?
The simple answer to this is an absolute YES!
However, there are pitfalls to look out for when you want to build a solar panel instead of buying already manufactured panels.
Studies show that even when working with an experts’ directions, many homemade solar panels fail after months due to moisture entering the panels, high temperature arcing, or total panel failure.
But if you are a techie and willing to put in the time, you can build a solar panel for yourself and be fascinated as you learn about this technology. You’ll also develop the necessary skills you’ll need if you plan to continue to build a whole solar panel system.
The key things to consider if you choose to build a solar panel includes;
- If you build a solar panel wrongly, you can cause a fire due to intense heat build up on hot, sunny days.
- Some websites like eBay often sell factory low-grade, rejected, or damaged solar cells, which is a recipe for disaster.
- Homemade panels are not eligible for incentives or rebates
If you want to build a solar panel, it is not so difficult since it is basically soldering and measurement of the framework itself. The difficult part is sourcing the best materials such as solar glass and solar backing sheet material.
These are not usually available to the public and building a solar panels using the wrong equipment can be extremely risky and dangerous. Now, let get to know what materials we will be needing for building our solar panel.
Materials needed to build a solar panel
The basic materials needed to build a solar panel include the following:
- Silicon solar cells
- Metal frame (typically aluminum)
- Glass sheet for casing
- Standard 12V Wire
- Bus wire and Tab wire
The basic tools that you will need when you want to build a solar panel are
- Soldering iron,
- Soldering lead,
- Solder paste or flux (for removing the grease off the wires),
- Silicone sealant.
- Wooden board and protective glasses,
- A multimeter to measure voltage and amperage.
- A pencil and a ruler.
NB: The most important material used to build a solar panel is the solar cell. Pay keen attention to the solar cells as they are really fragile and can be broken very easily, so you need to handle them with special care.
As there are different types of solar cell to buy, the best option for quality and durability are either made in the United States, China, or Japan.
In terms of type, the best option is polycrystalline solar cells since they are cheap and fairly efficient nowadays.. The number of cells you should buy depends on the amount of energy you’re looking to produce.
Things to know before buying solar cells
- Solar cells can most easily be bought online through websites like Ebay, but you may be able to purchase some from your local hardware store.
- It may be necessary to clean wax off of the cells, if the manufacturer ships them in wax. To do this, dip them in hot, but not boiling, water.
- Each cell shouldn’t cost more than $1.30 per watt.
Once your materials and tools are ready, lets get straight to the step by step guide on how to build a solar panel .
Step by step guide on how to build a solar panel
To better understand the process of building a solar panel, follow these steps accordingly.
1. Prepare your working table and tools.
It is very important to make sure you have enough space to work on before you decide to build a solar panel. You can choose a space in your garage or you a your room.
Either way, get a table and make sure you cover it with some rug. This way, the solar cells and the glass won’t get scratches. More so, the solar cells won’t hit a hard surface and break because its a fragile material.
I usually clear the space around the solar cells and leave them in the box until I really need to use them.
I also make sure to purchase about 10% extra solar cells when you order, most of the good sellers understand this and will send that extra solar cells.
Its not bad if you make mistakes when you want to build a solar panel, allow yourself to make those mistakes as you will learn a lot from this experience and in your second solar panel, you won’t make too many mistakes as well as you will be able to build it in half of the time it took you to build the first one.
2. Measure, Outline and Cut the Backing board
Place the square solar cells onto the wooden board and draw separating lines. This is to enable you know the size of the solar cell and calculate what the final size of the panel will be when completed.
Lay out the cells in the arrangement you will use, then measure the dimensions and cut a board to that size.
You will need a thin board made out of a non-conductive material, such as glass, plastic, or wood, to attach the cells to.
Be sure to also leave a space of an inch or 2 at both ends of the board. This will make room for your connecting wires to pass while soldering.
Wood is a more common backing material to choose because it’s easier to drill through. You’ll need to drill holes in it for the cell wires to pass through.
You can also chose white acrylic sheet to build your solar panels backing board because it is weather proof, corrosion proof and durable.
You must cut your pieces of clear and white acrylic to the exact dimensions of your solar panel.
Here is how you measure and cut your backing board:
As you have measured the length and breadth of your solar cell, multiply the value of the breadth by 4 and their length by 9(since were making a solar panel with 36 solar cells in it).
This will give you the approximate width and height of your two pieces of acrylic (the front and back sides of your solar panel), but don’t cut yet.
You must also make sure your measurements include about a 1/4 inch (.25 inches) of extra space in between each solar cell. They shouldn’t be touching each other.
Also leave about 1 – 2 inches of extra space between the outer edge of the solar cells and the outer edge of the entire panel to allow space for the aluminum frame.
Lastly, make sure you leave about 2 inches of extra space at the very top of the panel to make room for certain wires that will be running there.
When you have your first piece of acrylic (the clear one) cut to size, simply cut the other piece of acrylic (the white one) to the exact same measurements – so you can build solar panels that are uniform in size and shape.
Great! The front and back sides of your solar panel are cut and ready. Depending on the size of the solar cells you’re using, these acrylic sheets should be approximately 25-35 inches wide and 30-40 inches in height.
Below is a measurement format;
|If you use solar cells that are 6 inches wide and 3 1/4 inches high, the measurements for your two pieces of acrylic would be 6″x4=24″+ 2″+2″(sides)+.25×3= .75″ (space between panels) = 28.75″ width.And 3.25″x9= 29.25″+ 2″(top)+1″(top alloy frame) + 2″(bottom) +.25×8=2″ (space between panels)=36.25″ height.|
3. Measure and Cut the tab wire
The tab wire or tabbing wire connects the panels to each other vertically. They are run down the two larger lines in the panel and connect to the back of the next cell in the array.
Measure the length of that larger line, double the length, and then cut two pieces for each cell
4. Connect the individual cells in series to get the desired voltage.
After this, The next step involves, connecting your solar cells to each other. We will be connecting all of the solar cells in each vertical column together.
So we will be connecting 4 individual columns each consisting of nine solar cells, but let’s start with doing just one.
Use a soldering iron to melt a thin coat of solder onto the back of the cell strips.
This step is not necessary if you purchase pre-soldered tabbing, which is often a better option because it cuts time in half, heats up the cells only once, and wastes less solder. However, it’s more expensive
Using a flux pen, run 2-3 lines of flux down the length of each cell strip, or group of three squares. Make sure to do this on the back of the cells. This will keep the heat of the soldering from causing oxidation
After you planned the physical arrangement of the solar cells on the board, now start soldering the wires to the solar cells and then to each other.
First, link the cells in series.
Respect this basic rule, just like if you were soldering batteries: the positive lead is to be soldered to the negative lead of the next cell.
Do this for as many cells as needed to reach a voltage of 12 or 24 volts. Do not exceed that as you would enter the area of dangerous voltages.
You just need a minimum of 12 volts to kick-start a 12V inverter for generating 110/220V AC or charge your 12V battery packs. Linking the cell in series will increase the voltage.
Put a small amount of glue at the back-center of the cells and then press them into place on the board. The tabbing wire should run in a single, straight line through each row.
Make sure the ends of the tabbing wire are coming up between the cells and are free to move, with just the two pieces sticking up between each cell.
Keep in mind that one row will have to run in the direction opposite to the one next to it, so that the tabbing wire sticks out at the end of one row and on the opposite side of the next.
You should plan to put the cells in long rows, with a fewer number of rows. For example, three rows each consisting of 12 cells placed long side to long side.
Remember to leave an extra inch (2.5 cm) at both ends of the board.
5. Link the connected cells with the bus wire
The bus wire connects the series-connected solar cells to each other. To do this, stick the cells to the board using a glue carefully. But before you do that, drill holes where for the connecting wires to be passed individually on the board( total of two holes).
Make connection buses along the positive and the negative lead and then connect those buses (thicker wires) in parallel (plus to plus, minus to minus) to have a parallel connection. This increases the amperage of the solar cells.
Using a soldering iron, dip the tip of it into your jar of flux, apply some solder to each of the contact points and gently press the solder down against the tabbing wire and the contact (bus wire).
This should bond the tabbing wire to the solar cell’s positive contact point.
Now do the same thing for the second tab and you will have completed joining together two solar cell rail.
You must now continue to join more solar cells to the bottom of your “stringer” (column of cells) until you have 9 solar cells joined together in total.
The tabbing wire connected to the back of one cell should connect to the front of the next cell in every case
You will need to prepare the first cell of the second row with extra tabbing wire, as you did with the first. Connect all four wires to this bus wire
6. Measure the output voltage
Now that you have the tabbing wire and bus wire correctly soldered, all you have to do is put your solar panel system under sunlight. After a while, use a multimeter to measure the voltage and short-circuit amperage.
If the system is operating properly, the ammeter should bear the solar cells’ nominal power (ex. 96W at 12V means 8 amps)
After making sure the panels are working properly, you will seal the panels.
Use a piece of plexiglass and place atop the wood board to box in the solar panels. Seal the box using a silicone sealant to seal the edges of the box.
Also seal all gaps you come across as the box needs to be as watertight as possible. When complete, carefully screw the plexiglass into the wood along the edges. Do not get too close to the edge when doing this, as it’ll cause the glass to shatter.
7. Build the casing for the panels
Put you newly created solar panel on the board to trace and measure the size you need to cut. Add about 2 cm to each side to this measurement.
You need some space at the corners of your box for the bus wiring to be easily bent around.
Cut these pieces you have measured using your saw and secure them together using deck screws and butt joints.
It’s important that the sides aren’t too tall because then they may shade the cells when the sun is coming from a sharp angle.
8. Connect the terminals of the solar panel
The solar panels needs a positive and negative terminals to work properly. To connect the panels, buy a diode that has a bigger amperage than the panel (say 9 amps) and attach it to one of the exposed bus wires and secure it with silicone.
Your lighter colored side (white stripped end) of the diode should be pointing towards the negative end of the charge control and the other end to the negative side of your solar panel. This is done to stop electricity from moving back through the solar panels.
The charge controller regulates the charge and limit the electrical current so it can be used in everyday devices. Here you need to pay attention to the connection, negative and positive must be attached correctly.
There are colored wires that come with the controller. These wires must be run from the terminal block straight to the charge controller.
The dark colored wire will need to go from the negative side of the panel to the negative side of the charge controller and vice versa. The input panels on the charge controller are also color coded to help with this.
The charge controller needs to be attached to batteries that the solar panel will then charge. You will have to buy a battery that works with the output of your panel depending on its size.
Connect this battery to the charge controller by following the instructions that the manufacturer will have included.
9. Seal off any Leakages
Use a silicone sealant to seal the edges of the box. Also seal any gaps you can find so that box is as watertight as possible. Use the manufacturer’s instructions to properly apply the sealant
You can now seal the unit by using clear silicone on the edges. Seal up any gaps in the material as it needs to be watertight if you will be exposing it to harsh weather conditions.
10. Mount your solar panel
One option would be to build and mount your panels on a cart. This would place the panel at an angle but allow you to change which direction the panel faces in order to increase the amount of sun it gets in a day.
This will, however, require you to adjust the panel 2-3 times a day
This is a popular way to mount the panels because they tend to receive the most sunlight and are out of the way.
However, the angle will need to be consistent with the sun’s path and your peak load time. This will limit you to only getting full exposure at certain times of day.
You can now power anything that runs on DC current, charge your car battery and so on.
If you succeeded doing these steps, then you can order some more solar cells until you reach the power you want for your system. Remember, the more power you want, the larger the inverter you’ll need to get.
The most important factor to consider if you want to build a solar panel system is your level of technical know-how. If you are not a techie, you may find it difficult handling the tools and making the necessary calculations needed for the perfect solar panel system.
Be aware also that this is a very delicate project and requires utmost care. Use all the precautionary safety measures and gadgets to avoid the risk of electrocution.
Building your solar panel yourself can be a self satisfying investment which promises to save you some buck of you do it right. However, do not be dismayed if you are not able to get it right at the first instance, once you have done it twice or three times you will definitely get used to it and build a better solar panel for yourself.
I will like to know if you face any major challenges while building your solar panel. Feel free to let me know in the comment section below.