Solar Off-Grid Home Lights Project

Author : Dinesh Kumar Wickramasinghe

Hello Friends, This time I am writing about a different project. Not related to Arduino, or PIC or even Microcnotrollers.

This post is about the small off-grid Solar system I built recently. I could power-up all my home lights with this system. So I decided to share my experience with you.

When installing domestic solar systems, there are two types.

1) Grid-Tied Systems

These systems are connected to the main power grid. To install these types of systems, you need special knowledge and sometimes the supervision of qualified engineers or companies. Also these systems required expensive inverters and many more components.

2) Off-Grid Systems

These systems are not connected to the main grid. Isolated from the main grid. You do not need advance engineering knowledge. But you should first learn the basics about solar electric systems. You can do experiments with these types of systems. No need for expensive hardware.

My system has below equipment.

1) Solar Panel

This panel is a used one. I purchased from a local vendor. It's a 270W monocrystalline solar panel. When there is good sunlight, this panel provides max 35V and 7.5A current.

2) Lead Battery (12V 100AH)

This battery is also a used one I purchased from the same vendor that I purchased the panel.

3) Solar charge controller (20A PWM)

This device is important. You cannot connect the solar panel directly to the batteries. Because the battery can overcharge. So this type of device protects the battery from overcharging and over-discharging. Also there are some other features like monitoring and timers. (Please note that there are two types of solar charge controllers. Those are PWM and MPPT. MPPT controllers are expensive but more efficient than PWM)

4) 12V LED Strips

I used 12V LED strips in my house. But I had to use an extra wiring for them. I used white color speaker wires for the wiring.

In my charge controller, I configured some settings as below.

When the sunlight goes down, the controller turns on the output. Then after 11 hours it cut off the output supply. (These hours can be set in the controller)

So basically around 7.30 p.m, the controller turns on the lights and morning 6.00 a.m it automatically turns off the lights.

There are 8 LED strips running everyday with this system and I have zero electricity bill for my lights.

Please share your ideas, questions as comments. Depending on your feedback, I will write more articles about Solar energy. Have a nice day.