Inside a solar panel, there are several solar cells that are connected in both series and in parallel configurations. Therefore you cannot determine the voltage of a solar panel simply by counting the number of solar cells.

If you are handling a commercial solar panel, all you need to do is read the ratings from the datasheet. It shows you different numbers that are important…

For example, the open and closed-circuit voltage, the open and closed-circuit current and the power output under standard illumination intensity are some numbers you have to know.

However knowing these details may not be sufficient as the ratings are measured under ideal conditions. Your solar panel is subject to a different condition at the place where you install them. Therefore you still have to make a simple measurement using a multimeter.

Before you stick the multimeter probes on the solar panel output, recall the formula you learned in high school:

Power (Watt) = Voltage (Volts) x Current (Amperes)

It is not that easy to measure the power output using a simple current or voltage meter. But we can make a calculation after we know the voltage and the current output. (Multiplying these 2 numbers give us the answer we want.)

Each solar cell gives a voltage output of about (slightly more than) 0.5 volts direct current. This is true no matter how large your solar cell is. The only difference is the output current.

Thus if you have a 12 by 2 series configuration, you’ll end up with a solar panel that gives out more than 12 volts. This is ideal for charging a 12 volt battery.

(Note: To charge a 12-volt battery, you need much more than just 12 volts.)

Interestingly, if you break a solar cell into two halves, each of them will give an output of 0.5 volts. The only difference is the output current is now halved. This is why you can use broken solar cells to make a solar panel and it’ll still work.

Other Notes:

Your home solar energy system is made up of several pieces of solar panels that are wired together in an array. If you want their voltage to add up, you have to connect them in series. If you want their current to add up, you must connect them in parallel. No matter how you connect them, the total power output remains constant.

Continue Reading:

1. Important Facts And Properties of A Solar (PV) Panel You Must Know About (Part 1 of 3)
2. Important Facts And Properties of A Solar (PV) Panel You Must Know About (Part 3 of 3)
3. How To Build A Solar Panel Charge Controller

Trying to build a photovoltaic panel without basic skills is akin to a man who tries to be a painter without knowing the basic techniques of handling a brush…or toddler trying to cycle without developing a sense of balance. It is bound to be difficult — at least initially.

There are 3 essential skills necessary to build your own DIY solar panels. They are (1) handling of tools, (2) soldering & (3) a practical knowledge of electrical circuits.

Knowing how to handle materials is important. Whether you build solar panels using wood or metal, you have to understand how to manipulate the materials to shape them into the design you want.

This implies you have to know how to handle simple hand (or power) tools. Then you can cut the material or bend them. You’ll also need to finish (polish) the surface and edges so the burrs and jagged edges can be removed.

Inside solar panels are row after rows of electrical connections that have to be made by soldering. Therefore you also need to learn how to use a soldering iron to bond metallic joints. Bad solder joints can cause unnecessary resistance in the electrical circuit, lowering the effectiveness of your energy production. Fortunately this is a skill that can be acquired easily – often within 15 minutes or less.

Having a good working knowledge of how electronics work can be helpful. You do not necesssarily need to design your solar panel from scratch, but you will need to know how to implement the circuit design recorded on paper. It will also be useful to know some elementary electronics formula so you can size your solar panel system. Again, this knowledge is easily acquired if you take some time to read up.

Basic formulae that are needed for building electronic circuits can be easily found on the Internet or in your local library. Moreover there are also many books on homemade solar panels in bookstores that can help you with these basics.

Equiped with the above DIY skills, you can be assured that building DIY solar panels can become a rewarding hobby.

Continue Reading:

1. Insider Solar Power Generator Review: 3 Most Common Mistakes Hobbyists Make on Their First DIY Solar Panel Project
2. Used Solar Panels – How To Use Them To Build Cheap DIY Solar Panels
3. Homemade Solar Panels