A properly sized solar light means the system has just enough solar wattage, battery capacity, and LED fixture efficiency to operate at the project-required light levels every night for long time.
A solar street light consists of four main components:
1) PV module-converting solar energy to electrical 2) Battery- for energy storage. 3) charge controller-for charge/current flow regulation 4) light fixture-light source for illumination
let’s start our case study from load of our light fixture. Suppose we are using 50W of led light which will be operate for 10 hours a day. 50w*10h=500wh/day (means our light will consumes 500wh power per day).
To provides that much energy we will need a battery of 60Ah. The battery voltage is 12.8V
So, 60Ah*12.8V=768Wh (We take battery efficiency 70% which means we have to multiply 768 with 0.7) 768*0.7=537Wh
To charge the battery we use the solar panel. To find power of solar panel we have to divide the battery watt hours by solar irrigation hours in Pakistan which is 4-5 hours in Pakistan.
537wh/5h=107w (as solar panel efficiency always less than 100%). So here we recommend 120W solar panel.
Proper sizing is the most critical step in building a solar street light to ensure it will operate reliably over the long term.
If you want to know more about solar street lights visit; https://newon.pk/ or WhatsApp at 03439227883.