Basic DIY Solar system setup

DIY solar system is actually quite simple. It is certainly not rocket science.
It consists of 4 basic components - Solar Panel, Charge controller, battery and voltage converter or Inverter which I will describe further below.

1st is the solar panel which is made of Photovoltaic (PV) cells. They come in different sizes and wattage or power.There are 3 main types of PV cells namely Mono-crystalline, Poly-crystalline and Amorphous Silicon also called "Thin Film".

Amorphous are those found on calculators and low power devices. They are not so effective and require more area/space to produce the same amount of energy as crystalline panel.

The differences of these 3 PV panels will be discussed in another post.




2nd is the solar charge controller. This is probably the most important component in the whole setup. It's function is to regulate the voltage from the solar panel to the battery. Without the charge controller, the panel voltage (which can be as high as 18V for a 12V system), will be too high for the battery (which is between about 10.8V to 13.4V max)  and will damage it. The charge controller also has a second function of preventing the battery from over discharge which again may damage the battery. So in summary, the charge controller protect the battery from over-voltage, over-charging and over-discharging damage. There are 2 main types of charge controller, namely PWM (Pulse Width Modulation) and MPPT (Maximum Power Point Tracking) which we will discuss in another post.

3rd is the battery. The battery or battery bank is a temporary storage for excess solar energy produce by the solar panels. It is called a bank because you deposit energy during the day and withdraw the energy for use during the night. There are different types of batteries designed for different purposes. The most common type use in small solar setup is the Sealed Lead Acid (SLA)battery. For a small DIY setup, we usually work on 12V. Just in case some do not know how much is 12Volts, we connect 8 AA batteries in series and we will get 12V (8x1.5V). This voltage is consider quite safe as it is low compare to our main 230Vac.



4th is the load or the output. Depending on the usage, a DC to DC (12V to 5V) converter is sufficient for most activity like charging your mobile phone, AA/AAA rechargeable batteries, powering 12V LED lights, 12V fans, rechargeable vacuum cleaner. If you plan to go higher level like powering household appliances which normally work on 230VAC, then you will need a 12VDC to 230VAC power inverter. Most on inverter will be covered in later post.

How to connect them?
All these components work on DC and have positive (red) and negative (black) indicate.
All you need to do is the learn how to strip wires and connect them using a test pen or screen driver. The charge controller is command center and all other components such as solar panel, battery and load are connected to the charge controller with positive and negative labelled.

Connect the battery first, negative follow by positive, then the panel and the load. Some controller has a button to turn off the power to the load, so you should turn it off before connecting the load.

I also place an in-line fuse between the positive terminal of the battery and the charge controller and another in-line fuse between the positive terminal of the load and the charge controller.
The fuses should be of the same rating as the output of the charge controller. This is to prevent accidental short circuit which may cause over heating and fire.

You may need cramping tool to cramp the wire to terminal connecters but this is not a must. You can always twist the wire around the terminals and use an electrical tape to cover the wire.

So, that's it, a simple setup to begin with and explore as you gain more knowledge. For a DIY project, it's always good to start small and expand later when you acquire more knowledge and experience.
I started with 30W panel, 10A PWM charge controller, 9Ah battery and a 12V to USB converter.
At the time of writing, I have 90W panel, 30A MPPT charge controller, 69Ah batteries, 2 DC to AC inverters and other gadgets. I use it to power my 26W solar fan and 6W 1 meter LED lights, charge my handphone and rechargeable batteries and other rechargeable gadgets.

Happy solar harvesting!