Solar Panel Wattage Calculator

This solar panel wattage calculator allows you to calculate the recommended solar panel wattage according to the energy consumption of your household appliances. If you want to know more about solar panel sizes and wattage calculations, feel free to explore our fun and helpful solar panel calculator.☀️

Are you ready to find out the size of the solar panel your house needs? Let's go!

Solar power has become one of the most popular and accessible renewable energy solutions available today. Whether you're a homeowner looking to reduce your utility bills or an environmentally friendly individual committed to sustainable living, installing solar panels is one option that requires careful consideration.

Unlike traditional fossil fuels, solar energy is clean, renewable, and increasingly affordable as we discover new technologies. If you are planning to purchase solar panels to power your house, here are a few things to consider:

• Solar panel size — The more surface area it has to receive sunlight, the more energy it can produce.

• Solar panel efficiency — Monocrystalline panels have the highest efficiency compared to polycrystalline and thin-film panels. However, they are more expensive.

• Solar hours and climate of your location — The amount of sunlight is your energy source. Solar panels might not be worth it if you live somewhere with little sunlight.

• Roof size available for solar panels — How many solar panels can fit on your roof? Will they produce enough energy for your house?

• Angle of the setting and the roof — The optimal angle for solar panels is between 30 and 45 degrees.

• Energy consumption of your household — Find the total energy consumption from your electricity bills, and find out what kind of solar panel is the most suitable for you.

• The cost of solar panels and long-term savings — Normally, solar panels should help you save on electricity bills in the long run. Use our solar panel wattage calculator to find out!

If you want to reduce your house's electricity cost and see whether it's worth shifting to solar power, the first step is to know the correct size of solar panel you'll need. This solar panel wattage calculator will help you with that.

When deciding to switch or have solar as your electricity source, the first information you need is your total energy consumption. The real question is: "What kind of devices do you have in your house?" 🖥📠💻

Look at the table below for the approximate energy consumption from different household appliances per hour.

For each appliance, you can find how much electricity it needs in watt-hours per day by multiplying its wattage by the number of hours you use it in a day. Do this with all your appliances, and divide the total by 1,000 to find your total daily electricity consumption in kilowatt-hours per day (kWh/day). Then, estimate your yearly consumption by multiplying it by 365 days.

Read on to learn how to utilize this value to determine your recommended solar panel wattage requirement.

Calculating the solar panel wattage you need for your household is very easy. It starts off with the following equation:

Where:

• $\text{electricity consumption}$ (kWh/yr) – Total average amount of electricity you use annually. Found on your utility bill, and
• $\text{solar hours per day}$ – Average hours of direct sunlight per day in your location, which varies by country and, sometimes, city.

That is the basic solar panel size you would need to match your average electricity consumption in a year, while considering a 100% efficient solar panel. However, that's not the case in reality. You must consider adjusting the solar array output you need as follows:

where:

• $\text{bill offset}$ — Percentage of your energy consumption you want to cover with solar (e.g., 75% to eliminate 75% of your electricity bill); and
• $\text{environmental factor}$ — Percentage of energy stored, considering factors such as weather and shading due to dust and weather. Typically, it ranges from 70% to 90%.

As an alternative, you may want your solar panel to power only a portion of your house or a set of particular appliances, as in the illustration below.

If that's the case, find the total electricity consumption for those appliances and use the following equation:

If you need help finding the electricity consumption of the appliances in your household, you may find our electricity cost calculator very handy.

Our calculator is designed for ease of use, whether you're in the U.S., Canada, or planning to input your solar data. Here's how to get started:

1. Enter your electricity consumption. You can calculate it yourself by considering all your appliances, or only a group of them. You can also use your latest electricity bill's average kWh/year estimate.

2. Input the solar hours per day for your location. If you don't know it, you can tick on the "Use location-based solar hours", and select your country from the options. If you're in the USA or Canada, you can be more precise with your location by choosing your city. Upon doing so, our solar panel wattage calculator will display the average recorded solar hours per day for your selected location.

3. Next, enter your desired bill offset or the percentage amount of your bill that you want to offset. Enter 100% if you want your solar panel to cover 100% of your energy needs, or if you previously calculated the total electricity consumption for a select set of appliances. If you want partial coverage, enter a lower percentage.

4. Key in the environmental factor for your location. We set it by default 85%, which accounts for panel inefficiency, dust, and weather. That's also saying that we expect around 15% of the solar energy coming into the solar panel will go to waste.

Following these steps will give you your solar panel wattage requirement.