How Many Solar Panels Do I Need?

How Many Solar Panels Do I Need?

When we talk about solar power, the first thing that comes to mind is the solar PV panels, the central component of your solar power system. When determining to build a solar energy system, the first question that pops up is how many solar panels I need.

Well, it depends on five key factors:

Amount of energy you use on an average day
Peak sun hours in your city
Roof space available to install solar panels
The capability of your energy storage system
Your budget

AMOUNT OF ENERGY YOU USE ON AN AVERAGE DAY

• View your past utility bills

To determine the amount of energy your home uses in a typical month, week, or day, look on your bill for "kilowatt hours (kWh) used" or similar. Usually, this is the figure for 30 days’ usage, so just divide it by 30 to get a rough estimate of average daily energy consumption.

• Check your meter readings

Alternatively, you can take a look at your electricity meter readings. Take the most recent figure and subtract the previous one. Then divide the result by the number of days between the two readings, and there you have an average daily consumption figure. If you can, we suggest doing this several times, between multiple pairs of readings, to get a more accurate average.

• Use formulas to calculate manually

For a more thorough look at your usage, take the following steps:

Firstly, find out the wattage of each of your devices.

Most electronic devices have a label that details their wattage, typically found on the bottom or back; alternatively, you can see this information in the user manual.

If you can't find the wattage information, here are three ways to figure it out:

1) Use this formula to calculate it: watts = amps x volts

2) Use a wattage measuring tool, watt meter, or multimeter

3) Contact the manufacturer with your device's model number

4) Search your device online

Next, calculate watt-hours per day:

After figuring out the wattage of your electronic device, multiply it by the number of hours you use it in a day to get the watt-hours. For example, a 150-watt television is used for three hours per day:

Wattage of TV (watts) x hours TV is used per day= watt-hours (Wh) per day for TV

150 watts 3 hours= 450 Wh/day

At last, how many watts are in a kilowatt?

You'll notice that the electricity on your bill is measured in kilowatt-hours (kWh), not watt-hours. And one kilowatt equals 1000 watts. Take our TV that uses 450 Wh per day:

watt-hours (Wh) / 1000 = kilowatt-hours (kWh)

450 Wh/ 1000= 0.45 kWh

So, using a 150-watt television for three hours a day will consume around 0.45 kilowatt-hours of energy per day.

When calculating your overall household energy consumption, we recommend making a list of all the appliances and devices you plan on running and then using the above formula.