If you have the right roof for it, installing solar panels with microinverters is a great way to maximize your solar energy system’s efficiency. These panels are able to operate independently, maintaining the best possible performance even if one panel is shaded or malfunctioning.
Though installing solar panels is a complex job that requires professional work, it helps to understand the general requirements and process before taking on the project. In the video above, Ask This Old House host Kevin O’Connor and home technology expert Ross Trethewey explore the installation process and the benefits of using microinverters.
Assessing Your Roof for Solar Panel Installation
Before starting the installation process, you’ll need to determine whether solar panels make sense on your roof. Several factors affect your roof’s solar potential.
Roof Orientation and Pitch
The ideal roof for solar panels should face south and have a pitch between 30–45 degrees. This orientation and angle allow for maximum sun exposure throughout the day and year. If your roof doesn’t meet these exact specifications, solar panels can still be a viable option, but they may produce less energy.
Shading and Obstructions
Your roof should have minimal shading for optimal solar panel performance. Trees, nearby buildings, or other structures that cast shadows on your roof can significantly reduce the efficiency of your panels. Professional installers use specialized tools, such as the sun eye device in the video, to assess shading and determine the total solar resource fraction (TSRF) of your roof. The TSRF score helps in understanding the potential solar yield of your installation site, which is necessary for estimating energy production.
Roof Condition and Structure
Your roof should be in good condition and structurally sound to support the weight of solar panels. If your roof is older or in need of repairs, it’s best to address these issues before installing solar panels. A firm foundation will reduce maintenance costs related to roof repairs and solar panel adjustments.
Parts of a Solar Panel System With Microinverters
Each part of the solar panel system plays a valuable role in converting sunlight to usable electricity. Learn more about each part below.
Solar Panels
Solar panels are the main component of your system, converting sunlight into direct current (DC) electricity. Each panel typically consists of 60 silicon wafer cells and can produce around 260 watts of power. The efficiency of each panel depends on the quality of the silicon wafers and the manufacturing process. Advanced panels might offer higher wattage and better durability.
Microinverters
Microinverters are small devices attached to each solar panel that convert DC electricity into alternating current (AC) electricity, which is used in homes. Unlike traditional string inverters, which are only as strong as the weakest solar panel, microinverters allow each panel to operate independently, maximizing efficiency and performance. This setup provides better resilience against partial system failures and gives you precise monitoring of each panel’s output.
Racking System
The racking system secures the solar panels to your roof. It has stanchions, flashing, and aluminum rails that provide a sturdy foundation for your solar array. This system needs to be robust to withstand different weather conditions and keep the panels secure.
Wiring and Electrical Components
Various wiring and electrical components connect your solar panels to your home’s electrical system and the power grid. These include trunk cables, junction boxes, and disconnect switches. Proper installation of these components is vital for the safe and efficient operation of the solar energy system.
Benefits of Microinverters
Microinverters have several advantages over traditional string inverters in solar panel systems.
Increased Efficiency
With microinverters, each panel operates independently. This allows for maximum power production even if one panel is shaded or malfunctioning. This independence makes sure that the entire system isn’t affected by the performance of a single panel.
Easier Monitoring and Maintenance
Microinverters often come with web-based monitoring systems that allow you to track the performance of each individual panel. This feature makes it easier to identify and address any issues that may arise. You can pinpoint exactly which panel is underperforming and fix it without disrupting the entire system.
Flexibility in System Design
Microinverters allow for greater flexibility in system design because you can install panels on multiple roof planes or in areas with partial shading without significantly impacting overall system performance. This flexibility can be great for homes with complex roof structures or with limited direct sun exposure.
Enhanced Safety
Microinverters convert DC to AC at the panel level, reducing the risk of high-voltage DC running through the system. This can be a significant safety advantage since high-voltage DC systems can pose greater electrical hazards, including the risk of DC arc faults.
Microinverter Solar Panel Installation Process
Installing solar panels with microinverters involves several steps that only professional installers should follow. Here’s an overview of the process:
- Install roof stanchions and flashing: These provide the base for attaching the panels and prevent water leakage.
- Attach aluminum racking to the stanchions: This framework supports the panels.
- Mount microinverters to the racking system: Each panel’s microinverter is installed here to convert DC to AC power immediately.
- Connect microinverters to the trunk cable: This step integrates the microinverters into a unified electrical circuit.
- Install solar panels and connect them to microinverters: Panels are mounted and connected to their respective inverters.
- Run wiring from the roof to the electrical panel: Cables are safely routed from the rooftop to the home’s electrical control center.
- Make final electrical connections: Check that everything is correctly wired to the home’s power supply and the grid.
- Get electrical inspection and utility approval: Final checks by authorities guarantee safety and compliance. You need them before you can use your solar panels.
Grid-Tied Systems and Net Metering
Most residential solar panel systems, including those with microinverters, are grid-tied. This means they’re connected to the local power grid, allowing for an exchange of power supply and potential energy credits.
How Grid-Tied Systems Work
During the day, your solar panels produce electricity that’s used to power your home. Any excess electricity is sent back to the grid, potentially earning you credits from your utility company. At night or during periods of low solar production, you draw electricity from the grid as needed. This continuous flow makes it so you always have access to power.
Net Metering Benefits
Many utility companies offer net metering programs, which allow you to earn credits for the excess electricity your system produces. These credits can offset the cost of electricity you use from the grid during times when your solar panels aren’t producing enough power. Net metering can significantly reduce your electricity bills, making solar energy a financially smart option.
Considerations for Professional Solar Panel Installation
While the concept of installing solar panels with microinverters may seem straightforward, it’s a complex process that requires professional expertise.
Safety Considerations
Working on a roof and handling electrical components can be dangerous. Professional installers have the necessary safety equipment and training to perform the installation safely. Their expertise guarantees compliance with safety standards, which is important to protect both you and the installers.
Permitting and Regulations
Solar panel installation typically requires permitting and must comply with local building codes and regulations. Professional installers are familiar with these requirements and can handle the permitting process on your behalf. Failure to get proper permits can mean hefty fines and may stop you from using the system legally.
Warranty and Support
Many manufacturers offer warranties on their solar panels and microinverters, but these warranties may be contingent on professional installation. Additionally, professional installers often provide their own workmanship warranties and ongoing support. By having professional support, you can guarantee that your system operates efficiently and that any issues will be addressed quickly, giving you peace of mind about your investment.
Solar Energy Financial Incentives and Cost Considerations
Investing in solar panels with microinverters can be a significant financial decision. However, there are several incentives and rebates to make the investment more affordable.
Federal Tax Credits
The federal government offers tax credits for solar panel installations, which can cover a substantial portion of the costs. For instance, the Investment Tax Credit (ITC) can help reduce your federal tax liability, making solar installations more cost-effective.
State and Local Incentives
Many states and local governments offer additional incentives, including rebates, tax credits, and grants. These incentives can further reduce the initial cost of installation, boosting your return on investment.
Long-Term Savings
While the upfront cost might be significant, the long-term savings on your electricity bills can make solar panels a financially savvy choice overall. Reduced dependency on grid electricity means ongoing savings and potential earnings from net metering accelerate your return.
Resources:
Enphase Energy manufactures the microinverters used in this project.
Expert assistance was provided by SolarFlair Energy, Inc.