How Many Solar Panels Do You Need?

When you are considering adding a solar power system to your home, one of the first questions you’ll likely ask is “How many solar panels do I need?”

Understanding how many solar power panels are needed to meet your energy demands is crucial when looking at overall costs and practicality. This article will help you estimate your average power usage and calculate the rough number of panels needed to help you decide!

Estimating Your Average Power Usage

The first step in determining how many solar panels will be needed is to calculate (approximately) how much electricity your household or business will require.

There is a simple way to calculate this! 

1. Check your electricity bill – Your monthly utility bill will indicate how many kilowatts per hour (kWh) you consume on average. The national average for households is around 900 kWh per month, but this can vary greatly depending on the size of your home, the number of people living there, and your general electricity use.
2. Convert your consumption to daily use – To simplify calculations, break down your monthly kWh usage into daily usage. For instance, if you use 900 kWh per month:

900 kWh/30days=30kWh/day

1. Adjust for solar efficiency – Solar panels don’t produce the same amount of electricity every hour of the day. Depending on your location, you’ll likely receive an average of 4-6 hours of peak sunlight each day. For the sake of this example, let’s assume 5 hours of peak sunlight a day.
2. Calculate your system size – Divide your daily consumption by the average peak sunlight hours:

30 kWh/day/5 hours = 6kW

This means that you’ll need a 6kW system that can produce 30kW per day to cover your needs.

Building a new home and don’t yet have an energy bill?

If you’re building a new home in Canada and haven’t yet received an energy bill, there are several ways you can still estimate your monthly energy usage. Here are some options for getting a rough estimate:

1. Use a Home Energy Calculator

There are several online tools, like the Ontario Energy Board bill calculator or the Fortis BC home energy calculator, that can help estimate energy usage based on typical household activities and appliance use. Simply input information about your home’s size, number of occupants, heating and cooling systems, and major appliances to get a more accurate estimate.

Based on where you live, find a local energy calculator to give you more accurate information about your potential energy usage.

1. Consider Regional Climate and Heating Costs

Since heating is a significant part of energy usage in Canada, where you’re located will impact your energy needs. For instance, colder regions like Alberta, Manitoba, and Northern Ontario will require more energy for heating, especially during winter months. Warmer regions such as British Columbia’s coastal areas, will require less energy to be put towards heating, but air conditioning needs may play a bigger role.

1. Research Energy Usage by Square Footage

On average, Canadian homes use around 11,000 to 12,000 kWh of electricity annually. This will vary based on the size of your home.

• Smaller homes (under 1500 sq. ft.): 700-900 kWh/month
• Medium homes (1500-2500 sq. ft.): 900-1500 kWh/month
• Larger homes (2500+ sq. ft.): 1500-2500 kWh/month

Factors Affecting Panel Efficiency

Several factors can influence how many panels you’ll need, including:

• Panel wattage – Solar panels come in different wattages, typically ranging from 250W to 500W. Higher-wattage panels produce more electricity in the same amount of space, so you’ll need fewer panels overall if you choose a higher wattage.
• Sunlight exposure – If you live in a location that receives more sunlight, like southern regions, you’ll generate more electricity per panel. Conversely, if you live in an area with less sunlight, you’ll need more panels to compensate.
• Roof space and tilt – The available space on your roof and the angle of your panels also play a role in how efficiently your system operates. Ensure that your roof can accommodate the necessary number of panels.

High-Wattage Panels vs. Low-Wattage Panels

Let’s explore how the choice of panel wattage affects the number of panels you need.

High-Wattage Panels

If you opt for 500W panels, each panel will produce 500 watts of electricity per hour of peak sunlight. To meet a 6kW daily requirement, you’ll need:

6000 watts/500 watts per panel = 12 panels

Low-Wattage Panels

Each 250W panel produces 250 watts of electricity per hour. To meet the same 6kW daily requirement, you’ll need:

6000 watts/250 watts per panel = 24 panels

As you can see, opting for higher-wattage panels allows you to install fewer panels overall, which may be beneficial if you have limited roof space. However, lower-wattage panels are often less expensive, so the final choice may depend on your budget and space constraints.

Maple Leaf All Black Bifacial Solar Panel 570W and Maple Leaf 520W Monofacial Panels are two of our favourite solar power panels!

Grid-Tied vs. Off-Grid Systems

Another factor to consider when calculating how many solar panels you need is whether you’ll be using a grid-tied solar power system or an off-grid solar power system. The difference between these two types of systems can significantly impact your panel count.

Grid-Tied Solar Power Systems

With a grid-tied solar power system, you’ll remain connected to your local utility grid. During cloudy days or high energy demand, you can draw electricity from the grid to supplement your solar power. This means you might not need as large of a solar panel system to cover 100% of your energy needs, as you’ll have access to backup electricity when necessary.

Off-Grid Solar Power Systems

If you’re going completely off-grid, you’ll need to produce all of your electricity through solar power. This means you must account for peak consumption times and days with less sunlight. In this case, you may need more panels, as well as a battery storage system to store excess energy for use when the sun isn’t shining.

The Role of Battery Storage in Solar Power Systems

Incorporating battery storage into your solar power system can significantly enhance its efficiency and reliability, especially for off-grid solar systems. Batteries allow you to store excess energy produced during peak sunlight hours, which can then be used during the evening, on cloudy days, or during times of high electricity demand. This ensures a consistent power supply even when solar panels aren’t actively generating electricity.

Additionally, battery storage helps reduce reliance on the utility grid for grid-tied systems, allowing homeowners to save on energy costs by using stored power when electricity rates are higher. For those aiming for complete energy independence or maximizing their energy savings, integrating a battery system is a smart investment.

Learn more about solar power battery systems.

Calculating Costs

When estimating how many solar panels you’ll need, it’s essential to consider the cost per watt, as this can vary significantly between different panel types. Lower wattage panels are often more expensive per watt, and while their upfront cost per panel may seem lower, they often end up costing more overall.

Higher Wattage Solar Panels

Higher wattage panels not only provide more power per panel but also reduce costs in other areas. Since fewer panels are needed, you save on roofing hardware and installation expenses. This makes them more cost-effective, even if the initial cost per panel is slightly higher.

Lower Wattage Panels

Lower wattage panels may appear cheaper at first, but because you need more of them to reach the same total output, you’ll need more roof space and additional installation hardware, which can drive up the overall cost.

Here’s an example cost comparison for the same 6kW system:

• 12 panels at 500W each: $300 per panel x 12 panels = $3,600
• 24 panels at 250W each: $200 per panel x 24 panels = $4,800

While the 500W panels have a higher price per panel, they reduce the number of panels required, minimize installation costs, and save roof space, making them more cost-efficient overall.

Choosing the Right Number of Solar Power Panels for Your Needs

Choosing the right number of solar power panels involves a balance between your energy needs, space availability, and budget. By calculating your daily energy usage and considering factors like panel efficiency and system type, you can make an informed decision about how many solar power panels you’ll need to power your home or business properly.

Whether you choose a higher or lower wattage panel, remember that solar power systems are a long-term investment that will pay off in energy savings and environmental benefits over time.

Solar Power Store is Here for All Your Solar Power Needs

If you’re ready to start building your solar power system, give Solar Power Store a call! We have a wide selection of solar power panels, batteries, all-in-one systems, and more! From grid-tied to off-grid to hybrid systems, we have everything you need to easily transition to solar power energy!

We also provide technical assistance, can aid in equipment selection, streamline permit applications, and help design a suitable layout for your property.

Our products ship out of Canada in standardized packaging sizes to save you time and money.

Together, we can embark on your solar energy adventure today!