When winter arrives and the snow starts to fall, many homeowners with solar panels wonder how their systems will be affected. Will the snow block sunlight and reduce energy production? Do you need to worry about damage or maintenance?
In this article, we will explore what happens to your solar panels when it snows, address common concerns, and provide tips on how to keep your solar system running efficiently throughout the winter months.
Whether you’re a current solar user or considering making the switch, understanding how snow impacts solar panels will help you make the most of your investment year-round.
How Snow Affects Solar Panel Performance
A blanket of snow on top of solar panels will prevent sunlight from passing through ultimately reducing your solar systems power output. This is completely normal and expected.
Solar panels produce electricity for your home by converting sunlight into electrical energy through a process called the photovoltaic effect. When sunlight hits the solar cells in the panel, it excites electrons, creating an electric current.
The electric current generated by the solar panels flows through an inverter, which converts it from direct current (DC) to alternating current (AC), the type used in homes. This AC electricity is then distributed through the home’s electrical panel to power appliances and lights.
So when their is snow on top of the panels, it is blocking a good portion of the sunlight from hitting the solar cells that are inside the solar panel. They can still work in the snow, but their efficiency is reduced.
If that is the case, are you expected to anticipate having high electric bills in the winter? Let’s dive in to this.
How Snow Affects Your Electric Bill
Snow on solar panels can reduce power output, but this doesn’t necessarily result in higher electric bills.
Here’s why:
Advanced Design with LIDAR Software
Reputable solar installers use advanced LIDAR software to design your system. LIDAR creates accurate 3D models of homes and surroundings, performs detailed shade analysis, and optimizes system designs for efficiency. This ensures high accuracy, even in harsh weather conditions like snow.
Weather Considerations in Production Estimates
Solar designers account for inclement weather in their production estimates.
For example, at Cleanstart, we factor in 60 days of snow coverage when calculating your annual energy production. This over-estimation of snow ensures that even in the worst winter conditions, your system will still deliver the promised power. On top of that, our power production is guaranteed. If your system doesn’t meet the production guarantee, we will add more panels for free, reimburse you for the difference, or replace the system.
Any reputable solar company should offer similar guarantees. If so, your electric bill will not be affected by snow, as your new average “after solar” electric bill already considers snow coverage before you sign any agreement.
Real-World Example
Below is an actual solar proposal for one of our customers in Bergenfield, NJ:
The Year 1 Production circled in green is the guaranteed production estimate factoring snow, rain, shade, etc. This is what the customer can expect to produce the first year regardless of weather.
The 8,554 kWh is the production guarantee.
A highly reputable solar company will be conservative in their annual solar estimation to make sure that you are indeed getting the power that is promised to you. So in essence, a solar system installed and managed by a good solar installer will-in reality-produce more power than what is on the contract. Under promise. Over deliver. That is how it should be.
The $3/mo circled in blue below is their new average electric bill.
This amount is what they will see every month regardless of the season. This is because even though there is snow on the roof in the winter time, the solar system generated more power in the summer months which is used to credit their winter electric bills.
How Net Energy Metering Affects Your Electric Bills
The primary reason you can still enjoy low electric bills, even during winter, is due to an arrangement called Net Energy Metering (NEM) that you have with your utility provider when you switch to solar energy.
Net Energy Metering policies can vary significantly from one state or utility company to another. Here, we’ll focus on the main utility providers in the northeastern tri-state area to give you a clearer picture of how NEM works.
Seasonal Solar Production and Energy Use
For a typical home with an average energy offset, solar systems tend to overproduce during the summer and underproduce in the winter. This is due to longer daylight hours in the summer and shorter days in the winter, along with potential snow accumulation affecting solar panel efficiency.
Below is a production schedule illustration for a specific home, demonstrating how net energy metering operates throughout the year.
- Orange Bars: Represent monthly solar production.
- Gray Bars: Indicate monthly energy consumption.
Notice the orange bars for March, April, May, and June. The tops of these bars are circled, indicating overproduction months. During these periods, your solar system generates more power than your home consumes. This excess energy is credited to your account, effectively stored in an “energy bank” by your utility company.
During the winter months, when the orange bars are shorter than the gray bars, your solar production is lower than your consumption. However, thanks to Net Energy Metering, you are not billed for this additional energy usage. Instead, you draw from the energy credits accumulated during the overproduction months, maintaining lower electric bills year-round.
Solar Panel Durability
One common concern among homeowners with solar panels is the potential impact of snow weight on their solar systems. However, it’s important to know that most solar panel brands are designed to withstand significant weight, ensuring that snow accumulation won’t damage your panels.
Solar panels are built to be robust and durable, with the ability to endure various weather conditions, including heavy snow. Manufacturers rigorously test solar panels to ensure they meet industry standards for strength and resilience. These tests often include:
- Mechanical Load Testing: Solar panels are subjected to high pressure to simulate the weight of heavy snow. This ensures they can support substantial loads without bending or breaking.
- Environmental Testing: Panels undergo exposure to extreme temperatures and weather conditions to verify their performance and durability over time.
Weight Tolerance
Most high-quality solar panels are rated to withstand snow loads of up to 5400 Pascals (Pa), equivalent to approximately 112 pounds per square foot. This capacity is well above what most regions experience, even during heavy snowfall.
Installation and Structural Support
Proper installation is crucial to ensuring your solar system can handle snow weight. Reputable solar installers will:
- Assess Roof Strength: Before installation, professionals evaluate your roof’s ability to support the additional weight of the solar panels and potential snow accumulation.
- Use Quality Mounting Systems: Installers use robust mounting systems designed to distribute weight evenly across the roof, preventing stress on any single point.
Maintenance and Safety
While snow weight typically won’t damage your solar panels, regular maintenance can help ensure optimal performance:
- Snow Removal: In cases of exceptionally heavy snowfall, gently removing snow from your panels can help maintain efficiency. Use a soft brush or a specialized snow rake designed for solar panels to avoid scratching the surface.
- Monitoring: Keep an eye on your system’s performance during the winter months. Most modern solar systems come with monitoring software that allows you to track energy production and detect any issues early.
Wrap-Up: Maximizing Your Solar Benefits
With a good NEM policy and a reputable solar installer, the long story short is snow will not effect your solar panel production. With proper planning and a reliable solar provider, you can ensure that your system performs efficiently throughout the year, keeping your electric bills low regardless of the season. Whether you’re a current solar user or considering making the switch, this knowledge will help you make informed decisions and get the most out of your solar energy system.
