A Guide on How to Replace Your Roof with Solar Panels

Replacing a roof with existing solar panels requires careful preparation to avoid damage to the panels and ensure a smooth transition. The process involves assessing the roof’s condition, exploring financial assistance options, and coordinating with qualified professionals to handle both roofing and solar panel management. 

Proper planning not only protects your investment in solar energy but also ensures long-term durability for your roof and energy system.

Pre-Project Assessment

Before beginning a roof replacement, a thorough evaluation is essential. This step helps determine if a replacement is necessary and whether financial assistance is available to reduce costs.

1. Evaluate Roof Condition

The first step is to assess the roof’s current state to determine if replacement is necessary. Signs of deterioration include:

• Leaks: Water stains on ceilings or walls indicate moisture penetration.
• Missing or damaged shingles: Wind, rain, and sun exposure can cause shingles to loosen or deteriorate.
• Sagging or structural damage: A sagging roof could signal underlying damage to the support system.
• Aging materials: If the roof is near the end of its lifespan (typically 20-30 years for asphalt shingles), replacement is advisable.

Solar panels can impact a roof’s wear pattern. In some cases, they shield portions of the roof from direct sunlight and weather exposure, prolonging its lifespan. However, areas around panel mounts may degrade faster due to trapped moisture or concentrated weight distribution. A professional inspection will determine the overall condition and whether repairs or a full replacement are necessary.

2. Determine Eligibility for Free/Reduced Programs

Replacing a roof is a significant expense, but homeowners may qualify for financial assistance through various programs:

• Federal Tax Credits: The federal Investment Tax Credit (ITC) allows homeowners to claim a percentage of solar-related costs, which can include roof work necessary for solar panel installation.
• State and Local Rebates: Many states offer roofing incentives when replacing old roofs with energy-efficient materials, such as cool roofing or solar-compatible materials. Check with your state’s energy office for current programs.
• Utility Company Rebates: Some power companies offer rebates for energy-efficient roofing or solar system upgrades. For example, utilities in California, Arizona, and Texas have incentive programs for homeowners combining roof replacement with solar energy.
• Solar Company Incentives: Some solar providers offer roofing discounts when installing a solar system. For example, companies like Tesla Solar and Sunrun provide financing options that include partial coverage for necessary roof work.
• Nonprofit & Low-Income Programs: Programs like Habitat for Humanity or Weatherization Assistance Program (WAP) provide financial aid for qualifying homeowners needing structural repairs, including roofing.

Professional Coordination

Once the assessment is complete and financial options are explored, hiring the right professionals ensures a smooth and safe process.

1. Hire a Solar-Specialized Contractor

Not all roofing contractors are experienced with solar panel removal and reinstallation. Choosing a contractor familiar with solar-compatible materials—such as metal, composite shingles, or reflective roofing—can help ensure your new roof maximizes solar efficiency.

The roofing contractor and solar company must work together to:

• Safely remove and store panels before roof work begins.
• Inspect panel mounts and hardware to determine if any components need replacement.
• Reinstall panels with minimal downtime for solar energy production.

2. Verify Contractor Qualifications

Hiring a contractor with the right qualifications prevents costly mistakes and ensures compliance with regulations. Key qualifications include:

• Solar Certifications: Contractors should have experience handling solar panels, ideally with NABCEP (North American Board of Certified Energy Practitioners) certification. This certification signifies expertise in solar panel installation, removal, and maintenance.
• Roofing Licenses & Insurance: Verify that the roofing contractor is licensed and insured in your state. Licensed contractors adhere to building codes, while insurance protects against liability in case of damage or accidents.
• Experience with Solar Roofs: Look for contractors who specialize in solar-integrated roofing materials like standing seam metal roofs or reflective shingles. Some roofing companies work directly with solar providers, ensuring a seamless process.
• Local Building Code Knowledge: Requirements for solar panels and roofing vary by location. A qualified contractor will ensure compliance with wind uplift ratings, fire safety codes, and roof load-bearing capacity regulations.

Roof Replacement Process

Once the solar panels are safely removed, the roofing team can begin work. This phase involves stripping old materials, assessing structural integrity, and installing the new roofing system. Choosing the right materials and ensuring proper sealing are key factors in maximizing both roof longevity and solar efficiency.

Remove Solar Panels

Before roof replacement can begin, the solar panels must be safely removed and stored. This step should be handled by a professional solar technician to prevent damage to the panels, wiring, and mounting system.

Disconnect Systems

The removal process starts with shutting down the solar system:

• Power Shutdown: The inverter and main electrical disconnect must be powered off to avoid electrical hazards. This step ensures safety for both the roofing and solar teams.
• Dismantling Panels: Solar technicians will remove mounting brackets, wiring, and rails carefully to avoid damage. Each panel is unbolted and disconnected individually, ensuring no stress is placed on delicate photovoltaic cells.
• Inverter & Grid Tie Disconnect: In grid-tied systems, disconnection from the electrical panel is necessary to prevent backfeeding power into the home or grid.

Storage

Once removed, panels must be stored properly to prevent environmental and physical damage. Best practices include:

• Weather Protection: Panels should be stored in a dry, covered area or waterproof tarping to prevent exposure to rain, wind, and dust.
• Stacking Precautions: Panels should be placed on soft padding or racks to avoid scratching or cracking the glass. Avoid stacking them directly on hard surfaces.
• Secure Location: Panels should be kept away from heavy foot traffic or construction zones where they may be accidentally damaged.

Install New Roof

With the solar panels safely removed, the roofing contractor can begin the replacement process.

Material Selection

Choosing the right roofing material is crucial for longevity and compatibility with solar panels. Some of the best options include:

• Metal Roofing: One of the most durable and energy-efficient options, metal roofs can last 40-70 years and support solar panels with minimal wear.
• Asphalt Shingles: A cost-effective and widely used option, asphalt shingles are easy to install and repair but typically have a shorter lifespan (20-30 years).
• Tile Roofing: Popular in warmer climates, concrete and clay tiles provide excellent durability but require specialized mounting for solar panels.

Structural Checks

Before reinstalling solar panels, the new roof must be inspected for structural integrity and load capacity:

• Reinforcement for Panel Weight: Some older homes may require additional rafters or bracing to support the added weight of solar panels.
• Flashing & Seals: Proper sealing around panel mounts and roof penetrations is necessary to prevent leaks.
• Weather Resistance: Wind uplift resistance, hail protection, and proper water drainage should be verified to extend the roof’s lifespan.

Solar Panel Reinstallation

With the new roof in place, the solar panels can be reinstalled and connected to the electrical system. Proper alignment and mounting ensure the system continues to generate optimal energy output. Additionally, this phase provides an opportunity to upgrade panels or add battery storage for improved efficiency.

1. Reconnect Systems

Once the new roof is in place, the solar panels must be properly realigned, mounted, and connected to maximize efficiency.

Mounting

Solar panels should be installed at an optimal tilt angle, which varies based on geographic location:

• 30-40° tilt is ideal for most regions in the U.S., maximizing year-round sun exposure.
• Flat roof systems may require adjustable tilt racks to improve efficiency.
• South-facing orientation is typically the best option for solar capture.

Electrical Integration

After mounting, the system must be carefully reconnected to the home’s electrical grid:

• Wiring & Inverter Setup: All electrical connections must be properly secured to prevent power fluctuations or malfunctions.
• Grid-Tie Verification: In grid-tied systems, utility companies often require a final inspection and approval before reconnecting to the power grid.
• Microinverters vs. String Inverters: If upgrading, microinverters can be installed to improve efficiency by converting energy at the panel level instead of relying on a single central inverter.

2. Upgrade Opportunities

Since the solar system is already disassembled, this is an ideal time to consider upgrades that enhance energy efficiency and sustainability.

Panel Efficiency

Older solar panels degrade over time, typically losing 0.5-1% efficiency per year. If panels are nearing 15-20 years old, replacing them with modern high-efficiency panels (e.g., monocrystalline or bifacial panels) can increase overall energy production.

Battery Storage

Adding a solar battery storage system allows homeowners to store excess energy for use during power outages or at night. Some top battery options include:

• Tesla Powerwall: A lithium-ion battery that integrates with existing solar systems to provide backup power.
• LG Chem RESU: A compact, high-capacity battery system that improves energy self-sufficiency.
• Enphase IQ Battery: A smart home energy solution designed for seamless integration with Enphase microinverter systems.

Post-Installation Checks

After the solar panels have been reinstalled, it is crucial to verify that they are operating efficiently and that the new roof is structurally sound.

1. System Testing

To ensure the solar system is producing the expected energy output and the roof is free from installation issues, post-installation testing is essential.

Performance Monitoring

• Inverter Displays and Apps: Most modern solar systems come with monitoring apps that allow homeowners to track energy production in real-time. Platforms like Enphase Enlighten, Tesla App, or SolarEdge Monitoring provide insights into daily and historical power output.
• Baseline Comparison: If you have historical solar production data, compare new energy output figures with previous readings to identify any discrepancies.
• Panel-Specific Analysis: Systems using microinverters allow monitoring of each panel individually, helping detect potential failures or shading issues.

Safety Inspections

• Leak Detection: Since solar panels require roof penetrations for mounting, an inspection should verify that flashing and sealants are properly installed to prevent leaks.
• Structural Integrity: The weight of solar panels can impact roof stability, especially on older homes. A final inspection by a roofing specialist ensures proper load distribution.
• Electrical System Check: A professional electrician should verify that wiring and connections are secure to avoid electrical hazards.

2. Permits and Compliance

To reconnect the system to the grid and ensure ongoing warranty coverage, homeowners must complete final administrative steps.

Utility Reconnection

• Permit Approval: Most areas require a final inspection from local building authorities before reconnecting solar systems to the grid.
• Electricity Provider Notification: Utility companies may need to approve the system before granting Permission to Operate (PTO) in net-metering programs. Processing times vary, so contacting them early can prevent unnecessary delays.
• Meter Replacement: Some homes require a bi-directional meter upgrade to accurately track both energy consumption and solar energy sent back to the grid.

Warranty Reviews

• Roof Warranty Updates: Roofing warranties can vary depending on materials and contractor policies. Ensure that solar panel installation did not void any roofing warranties by confirming with both the roofer and solar provider.
• Solar Panel Warranty: Many solar panels have 25-year performance warranties, but inverters and batteries often have shorter coverage periods. Check for new documentation or maintenance requirements from the manufacturer.

Maintenance and Upkeep

Ongoing maintenance is essential to keep both the roof and solar system in peak condition. Preventive care minimizes unexpected repair costs and extends the lifespan of your investment.

1. Roof Care

Maintaining a clean and debris-free roof helps prevent water damage and preserves structural integrity.

Debris Removal

• Gutter Cleaning: Leaves and debris can clog gutters, leading to water buildup and roof leaks. Cleaning gutters at least twice a year—especially after fall and storm seasons—prevents these issues.
• Roof Valleys & Drainage Areas: These zones are prone to accumulating leaves and debris, which can cause water pooling and premature wear. Using a soft brush or leaf blower can keep these areas clear.

Panel Cleaning

• Dust and Pollen Removal: Solar panels work best when clean. Over time, dust, pollen, and bird droppings can reduce efficiency by up to 5-15% if left unchecked.
• Soft Washing Methods: Using a soft-bristle brush with soapy water or a low-pressure hose is recommended. Harsh cleaning methods (e.g., pressure washers) can scratch the glass surface and reduce panel efficiency.

2. Solar System Monitoring

Regular monitoring helps detect issues early, ensuring consistent energy production.

Performance Tracking

• Energy Dip Alerts: A sudden decrease in power output may indicate shading from new tree growth, dirt accumulation, or faulty wiring. Many monitoring apps provide automated alerts for unusual energy dips.
• Shade Management: If trees have grown significantly since installation, trimming branches can restore optimal sunlight exposure.

Battery Maintenance

• Temperature Considerations: Battery storage units, such as the Tesla Powerwall or LG Chem RESU, require a controlled environment to maintain performance. Extreme temperatures can reduce battery lifespan and efficiency.
• Firmware Updates: Some smart battery systems receive software updates to improve charging algorithms and longevity. Regularly checking for manufacturer-recommended updates ensures maximum performance.

Key Considerations

Timeline

A full roof replacement with solar panel removal and reinstallation typically takes between 2 to 4 weeks, depending on:

• Permit processing times from local authorities.
• Weather conditions that may delay roofing work.
• Utility company approval for grid reconnection.

Cost Factors

Replacing a roof with solar panels can be expensive, but financial assistance programs may help offset costs. Homeowners should check for:

• State and federal tax credits that cover a percentage of the project cost.
• Solar financing programs that bundle roof and solar work into one loan.
• Utility rebates for energy-efficient roofing materials.

Avoid DIY Risks

Attempting DIY panel removal or reinstallation can be costly and dangerous:

• Roof Damage: Improper handling of solar mounts can lead to leaks and structural issues.
• Electrical Hazards: Mishandling wiring may result in short circuits, fire risks, or voided warranties.
• Voided Solar Warranties: Many solar manufacturers require professional installation to maintain warranty coverage.

Roof Replacement With Solar Panels

Now that you've learned the ins and outs of replacing your roof with solar panels, you're well on your way to harnessing renewable energy while enhancing your home's resilience. As you continue to explore the world of solar roofing, remember that each project is unique, with its own set of challenges and opportunities.

In another insightful piece, we'll dive deeper into the specifics of roof replacement with solar panels, covering everything from cost considerations to environmental benefits. Whether you're a homeowner or a builder, staying informed about these innovative solutions can help you make the most of your investment.