How Much Solar Panel Do I Need? A Step-by-Step Guide

A Guide to Sizing Your Solar System

Nobody can deny the importance of Solar panels. Are you considering going solar and wondering how much solar panel you need? Sizing your solar system may seem daunting, but it’s actually quite simple. In this guide, we’ll walk you through the steps to calculate how much solar panel you need for your property.

Step 1: Determine Your Energy Consumption

To estimate your solar system size, you’ll need to know how much energy you consume. The best way to find this information is by looking at your utility power bill for the last 12 months. Locate the kilowatt-hours (kWh) for each month and add them up. If your bill has a summary chart, you may find your total kWh there.

As an example, let’s say the total kWh for the year is 11,000.

Step 2: Find Your Solar Hours per Day

The next piece of information you need to determine your solar panel size is your solar hours per day. This refers to the number of hours of sunlight your location receives each day. In the USA, the average solar hours per day range from 4-6 hours. However, this number can vary depending on the season and location.

To find your solar hours per day, scroll down the page to find your state and nearest city for the solar hours. For example, Birmingham, Alabama, has 5.26 solar hours per day.

Step 3: Decide on Power Bill Offset

The final piece of information you need to size your solar system is the amount of your electricity bill you want to offset. This can range from 50% to 150%. For this example, let’s say you want to offset 100% of your bill.

Step 4: Calculate Your Solar Panel Size

Now that you have all the information you need, it’s time to calculate your solar panel size. You can use an online solar calculator or follow this simple Formula:

Solar Panel Size = Total kWh ÷ (Solar Hours per Day x 30)

Using our example, the solar panel size would be:

11,000 ÷ (5.26 x 30) = 70.4 kW

So, you would need a solar panel system that generates 70.4 kW to offset 100% of your energy consumption in Birmingham, Alabama.

Protecting Your Solar Panels with Surge Protectors:

As you plan your solar panel installation, it’s important to consider protection from power surges. Lightning strikes, power grid outages, and other electrical disturbances can damage your solar panels, inverters, and batteries. This can result in costly repairs and downtime.

One solution to protect your solar panel system is to install surge protectors. Surge protectors can absorb the excess energy caused by power surges and prevent it from damaging your equipment.

There are different types of surge protectors available, including AC surge protectors and DC surge protectors. AC surge protectors are installed on the AC side of your solar inverter, while DC surge protectors are installed on the DC side of your solar panels.

Consult with a licensed electrician or solar installer to determine the best surge protection solution for your solar panel system.


In conclusion, sizing your solar system is a straightforward process that requires you to determine your energy consumption, solar hours per day, and power bill offset. With this information, you can calculate the solar panel size you need to offset your energy consumption. Additionally, consider protecting your solar panels with surge protectors to prevent damage from power surges.

If you’re interested in learning more about surge protectors and how they can protect your solar panel system, be sure to check out our other articles on the topic How much surge protection do I need.

We cover everything from the importance of surge protection for solar panels to the different types of surge protectors available on the market. By investing in a quality surge protector, you can ensure the longevity and reliability of your solar panel system, and our team at Surge protection is here to help guide you through the process. You just need to comment below with your query.

Also read: Best Surge Protector for Home Theater

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