by Jerome Auza
It has been quite a while that I have reported anything about my solar energy experiments. This week, with lots of summer sunshine, I was able to power up the perimeter lighting and right of way lighting of Auza.Net without having to switch to the grid.
I finally got a new 300 watts, 48 volts solar panel and have set it up to add energy production on my initial setup. The challenge was that my setup is currently only 24 volts. After some reading and experimentation, I determined that the 48V panel is okay to use in a 24 volt system. This is because the solar panel need to be of higher voltage compared to the batteries and the panel voltage would just follow the battery voltage.
So my setup now is composed of a 128W, 24V panel and a 300W, 48V panel configured to function in a 24V system. By doing this, I am actually only using about half of what the 300W panel is capable. This is because the current produced by a solar panel does not change much if the battery voltage is changed. Based on the current and voltage measurements, I am currently able to produce 240W from my two solar panels.
When my second 48V panel will arrive, I will also need to get a 48V inverter and setup the system to 48V to maximize the power production. I will then have to remove my 24V panel at that time and setup the charge controller to 48V.
In addition to the new 300W panel, I also had to change the angle of the panel installation now that the sun is directly above us at noon time. So my panels are now facing upwards and not tilted 30 degrees to the south.
I am now happy to have a projected savings of about Php300/month. In the next several months, the aim is to be 100% off the grid.