Understanding System Performance
Understanding Your Solar System
With your solar system installed and producing clean, renewable energy, consider the factors below to help maximize the benefits of solar production.
You will see changes in your system’s production throughout the year based on the number of hours of sunlight and proximity of the sun. These seasonal factors are all considered in creating your final solar system design. Specifications regarding the equipment installed with your solar system are also included in your final design.
While you cannot control the sun or cloudy weather, a number of other factors may be considered to help you maximize the energy produced from your system. Shade from tree growth or routine exposure to outdoor elements resulting in dirt and debris accumulation can impact your solar energy. We recommend maintaining your solar system to get the most out of your solar system. If you see a significant change in energy production, follow the troubleshooting steps for your system.
Winter and Summer Energy Production
It is typical for your system to output 50% of its rated power at noon in the winter and 80% of its rated power at noon in the summer. The factors below can affect your solar production during the winter:
- Less Daylight
Compared to summer days, winter days are shorter and experience less daylight. As a result, your solar system operates for less time each day, producing less energy each day on average.
- Lower Sun Angle
During the winter, the angle of the sun changes significantly — the sun is much lower in the sky, even at its midday peak. As a result, your solar panels are hit with less direct sunlight during the winter months. This reduces power output for your system, causing lower energy production.
- More Snow Cover
Depending on your location, the winter months can bring increased snowstorms and cloudy weather, causing a layer of snow cover to form on your rooftop. With a thin snow cover, your system may still be able to turn on and produce a small amount of solar energy. However, a larger buildup of snow on your solar panels may prevent your system from producing energy until your panels are cleared.
Solar panels are an investment for your home and can continue to provide you with clean energy savings well into the future. Homes with solar panels rely less on the grid and can capture energy directly from the sun. Many homeowners can completely offset their energy usage with solar panels and significantly reduce or eliminate their energy bills altogether. By installing a solar panel system and customizing for savings through the Tesla app, you can take control of your energy usage and lower your cost. Learn more about how Tesla saves you money.
Additional efforts can be taken to maximize the value of your energy production. The use of high efficiency appliances and light fixtures allows you to use less energy in your home. Additionally, understanding your utility rate plan is key for taking advantage of your Net Energy Metering (NEM) credits and reducing energy consumption during higher time of use (TOU) rate plans. Each utility rate plan is unique; learn more about your utility bill after solar.
Maintaining Your Solar System
Tesla solar panels are designed to produce clean energy for decades. There are several best practices to get the most out of your solar system.
Keep Your Solar Panels Clean
You can maintain system performance by occasionally cleaning your panels to remove accumulated dust, pollen and leaves. Cleaning once or twice a year is typically sufficient, however, more frequent cleaning may be necessary during drier seasons as dust tends to collect on the panels. Ordinarily, you can rinse off panels with a water hose from ground level to remove accumulations. Rinse only the glass cover of the panels; do not rinse wiring or areas underneath panels. For safety and performance reasons, rinse panels only when the sky is overcast, or when the sun is low in the sky, as panels can become hot under intense sunshine. If you have excessive soiling, such as bird droppings, you may wish to hire a local solar panel cleaning service.
Prevent Shade on Your Solar Panels
Shade on your solar panels can hinder electricity production. Keep trees or other tall plants trimmed to prevent shade on your solar panels.
Monitor Your Solar Panel Production
The Tesla app shows real time and historic energy production of your system. Learn more about monitoring your system.
Frequently Asked Questions About System Performance
Will I still receive a utility bill after turning on my system?
Yes. You will continue to receive a utility bill after your system is installed, as your home will still be connected to your utility’s grid. The utility bill will reflect any unused energy that your system produces and sends back to the utility grid, often referred to as Net Energy Metering (NEM). The utility bill that you receive after installation tracks these NEM credits, the additional energy your household consumes from your electric company and any general service charges. You can view billing details for your system in your Tesla Account.
Why do my utility bill and Tesla app show different solar production?
Once energy is produced, your solar system is designed to immediately supply that energy to your home. Any energy production not immediately needed in the home will be used to recharge your Powerwall. Only after your home energy needs have been met will the remaining energy production flow back to the utility grid. Since your utility meter is only able to track the energy leaving or entering the utility grid and cannot capture the energy used directly from your solar panels, your utility bill will look different than the production displayed in your Tesla app. Learn more about net metering, utility credits and your utility bill after solar.
Will my production change over time?
The process of converting solar energy will cause the system to degrade in efficiency by approximately 0.5% each year. This is normal for solar equipment and occurs with every system. This is also accounted for when we design your system.
Will solar offset 100% of my consumption?
Your Tesla solar system is designed to best meet your original solar needs. These factors include aesthetics, maximizing production and cost-savings. Your energy usage may change over time, which may impact the ratio of energy supplied by your solar panels. Seasonal changes, such as decorating your home for the holidays, increasing heating or cooling in your home or changing the time or frequency for charging your electric vehicle may result in temporary changes in your utility consumption. Increasing or decreasing family members living in the home, adding new appliances or building additions to your home will result in more permanent changes to your energy usage. Regardless of your current energy usage, any amount of solar energy produced will be reducing the amount of energy you purchase from your utility company.
What should I do if my inverter needs service?
Tesla designs your system with the highest quality equipment, ensuring your system is designed to produce clean energy for decades. Some basic troubleshooting may be required from time to time. If you do experience issues with your system, follow the troubleshooting steps for your inverter.
Will my solar panels still operate during a power outage?
Even if you have solar panels, your home will lose power if there is a power outage in your area. For safety, solar equipment is required by law to shut down during a power outage. Your solar system is paired with Powerwall to maintain power and continue generating energy during an outage.
What should I do about snow or ice on my solar panels?
Do not shovel snow off of your solar panels. While accumulated snowfall can cover panels and temporarily reduce production, this is not a cause for concern. Your system is designed with annual energy production in mind, and occasional inclement weather is expected.
Can I try to make fixes or repairs to my solar panel system?
Please do not attempt to fix or repair your solar panel system. Your solar panel system contains high voltage electric current and contact can result in burns, sparks and lethal shock. Do not disconnect wires, open electrical panels or modify/damage the equipment in any way. If you are experiencing issues with your system, you can contact Tesla through your Tesla Account, reach out to us via chat or submit a question through our Contact Us form.
Can I add a couple more solar panels to my current system to increase production?
After your system is installed, we are not able to add individual panels to the original design. However, depending on your energy needs and your remaining roof space, we may be able to add a second system. Learn more about designing a second solar panel system.
What should I do if I need to replace my roof after I've already installed solar panels?
Tesla makes the system removal and reinstallation process simple, offering competitive pricing (unless otherwise listed in your contract) or providing you with the freedom of choosing your own contractor to complete the work. Log into your Tesla Account to contact Tesla Customer Support and begin this process.
If you decide to go with your own contractor, you will first need to contact Tesla and provide us with the following details: business name, the contractor’s point of contact and the contractor’s business email address. If you have a solar loan, please contact Mosaic or Sunlight Financial prior to contacting Tesla to initiate this process.