What Size Solar Panel Do I Need?
When you plan to install the solar power system in your home or commercial space, you need to know what size of solar panel or how many solar panels actually you need based on your daily usage. Also, you need to install not only solar panels but also a battery and inverter. So it is very important to have some idea about what size solar panel, battery, and solar inverter you need.
So, an obvious important question frequently peeks into your mind: What size solar panel do I need? Today we’re going to answer what size of solar panel you need exactly to maintain your daily usages of home appliances in the simplest possible way.
Let’s figure out how much energy we are consuming on a daily basis. I am going to give you a certain watt-hour charge load calculation. So, we can easily find out what size of solar panel, and how many solar panels we need to install, to maintain our electricity consumption.
First of all, we need to calculate how much energy we are using daily. That means we need to calculate total watts from our home appliances and how many times we are going to use them. Then converts watts into AMPs. After that transformation, we will pick market-available solar panels and convert their Watts into AMPs.
Finally, Divide total daily consuming AMPs by total solar AMPs. The final result will be the number of solar panels we need to install.
So, dive into the solar size calculation.
Calculate how much energy we generally consume daily?
Let’s consider, we use a 200 watts fridge for 10 hours (A fridge has a 30–35% duty cycle), a 1200 watts toaster for 30 minutes, 100 watts 4 ceiling fan for 10 hours, 900 watts 2 AC for 5 hours, 10 watts 20 LED lights for 8 hours and we are going to use the on-grid system. Also, we have a 12-volt system.
Now it’s time to calculate the total watts:
1 Fridge = 200 x 8 = 1600 Watts
1 Toaster = 1200 x 0.5 = 600 Watts
4 Ceiling fan = 4 x 100 x 8 = 3200 Watts
2 AC = 2 x 900 x 5 = 9000 Watts
20 LED lights = 20 x 10 x 8 = 1600 Watts
Total = 16000 Watts Daily
Transform Watts into AMPs
We know,
AMP = Watts / Volt
= 16000 / 12
= 1333.33 AMPs Daily
Now, calculate how much watts we are getting from the solar panels.
In Victoria or New South Wales, Australia, we will easily get 12–14 hours of sunlight. Let’s consider, we will get an average of 12 hours of sunlight to power up our solar panels. Also, in the Australian market, the most common solar panel size is 300 watts.
If we get 10 hours of Sun Power, the total Watts from a single panel will be:
1 solar panel = 300 x 12
= 3600 Watts Daily.
But, remember one thing that solar panels are a maximum of 15–20% efficient. That means that if we have a 100 watts solar panel on an average sunny day, it will provide 20 watts of energy per hour maximum.
Now calculate the solar panel total watts considering efficiency:
20% of 3000 Watts = 3600 x 20%
= 720 Watts Daily
Transform Watts into AMPs
We know,
AMP = Watts / Volt
= 720 / 12
= 60 AMPs Daily
It’s time to figure out what size of solar panel I need or how many solar panels need to be installed.
Our consumption amount = 1333.33 AMPs
Getting amount from a panel = 60 AMPs
Total Solar Panels we need = Total consumption amount / Getting amount
= 1333.33 / 60
= 22.22 or 23 solar panels.
Finally,
We had figured out that we need to install 23 solar panels (300 watts) with a 5 KW system to maintain our regular energy consumption.
