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How Long Does It Take to Install Solar Panels?
- 2 days ago
- 9 min read
Key Takeaways:
Most solar panel installations take 60 to 90 days from contract to activation, even though the physical installation itself only takes one to three days.
The timeline is extended by key steps such as system design, permitting, and utility approval, all of which must be completed before your system can go live.
Preparing your home in advance, including checking roof condition, clearing access points, and reviewing local requirements, helps prevent delays during installation.
The consultation and site assessment stage determines system size, panel placement, and projected energy production based on your energy usage and property conditions.
Permitting and utility interconnection take the longest, with approval timelines varying by state and utility provider before installation can begin.
After installation, inspection, and utility approval are required before activation, at which point you can monitor system performance and begin receiving energy credits if enrolled in net metering.
Table of Contents
If you've been thinking about going solar, you’ll likely wonder how long it takes to install solar panels. Generally speaking, you’re looking at anywhere from one to three months, depending on where you live, the size of your chosen solar energy system, and how quickly your local authorities process permits.
That answer surprises many people, especially when the physical installation on your roof takes only one to three days. But reviewing solar energy system designs, applying for permits, coordinating with utility providers, and sourcing components like racking systems and the panels themselves takes longer. In this guide, we’ll go into the installation timeline in greater detail, so you can better plan your project.
How to Prepare Your Home for Solar Installation
Preparing your home in advance can help keep your solar installation on schedule and
reduce the risk of avoidable delays. Start by evaluating the condition of your roof. Since most solar systems are expected to operate for 25 years or more, any aging shingles, leaks, or structural concerns should be addressed beforehand. Once that’s done, we recommend that you take the following steps:
Make sure that installers have clear access to key areas of your home. This includes your main electrical panel, garage walls (for inverter or disconnect equipment), and attic space if wiring must be routed internally.
Trim back overhanging branches to improve performance and help your system meet its projected energy production.
Gather recent utility bills in advance of your consultation. These invoices, which are a record of your energy usage, allow for more accurate system sizing.
Review any local or homeowners association requirements. Securing approval in advance can prevent administrative delays once your installation is ready to move forward.
What Happens During Your Solar Consultation and Site Assessment?
The solar installation schedule begins when you reach out for a consultation. When you contact Solair Green Energy Advisors, we’ll touch on important areas like:
The condition of your roof
Your financial goals
Your advisor will review your recent utility bills to calculate your average monthly kilowatt-hour usage, which determines the size of the system you'll need. That number drives every other decision, from how many panels go on your roof to which state and federal incentives apply to your project.
Pro Tip: Energy usage evaluation goes beyond billing history review. Your property is also reviewed to calculate how electricity is being distributed. This includes examining the following:
HVAC systems
Major appliances
Insulation performance
Roof angle
Sun exposure
Shading
How Solar Companies Assess Your Property
With your energy usage confirmed, your solar advisor will go on to assess the property itself. This involves evaluating your roof's age, slope, orientation, and layout to confirm it can support a solar array. For example, a south-facing roof with a fixed panel tilt of 39 to 41 degrees produces the highest annual energy output for homeowners in Delaware and New Jersey.
State | Latitude Range | Optimal Fixed Tilt |
Delaware | 38.5° to 39.8° N | 39° to 40° |
Maryland | 37.9° to 39.7° N | 38° to 40° |
New Jersey | 38.9° to 41.4° N | 39° to 41° |
Pennsylvania | 39.7° to 42.3° N | 40° to 42° |
Your advisor will also check for shading from trees, chimneys, or neighboring structures like sheds and gazebos. Because Enphase microinverters allow each panel to operate independently, you’ll need to be sure that the shaded panel doesn't pull down the output of the rest of the array.
How Long Does the Solar Energy System Consultation and Assessment Take?
The consultation and site assessment stage usually takes one to two weeks from your first call to a final system proposal. You'll receive a detailed layout showing the following:
Number of REC panels
Their exact placement on your roof
The projected annual energy production in kilowatt-hours
Your estimated savings based on your current utility rate
Once you approve the design and sign your agreement, the permitting stage begins.
How Long Does Solar Permitting Take?
Once you sign your agreement, Solair's design team creates your full system plan using the data gathered during your site assessment. This includes:
Calculating the exact number of REC panels needed to meet your kilowatt-hour target
Mapping their placement across your roof to maximize exposure
Specifying the Enphase microinverter for each panel
The design also accounts for your main electrical panel's capacity, since some homes need a panel upgrade before a solar system can be safely connected to the grid. Solair handles this review in-house, so you don't have to coordinate with a separate electrician.
What Solar Permits Are Required?
Before any panels go on your roof, your installer must pull permits from your local building department and submit an interconnection application to your utility company. The building permit covers the structural and electrical work involved in the installation, and the inspector who signs off on it confirms that the racking system, wiring, and conduit all meet local code.
Pro Tip: The interconnection application is a separate submission to your utility provider, requesting permission to connect your system to the grid and, where applicable, enroll in net metering so you receive credits for excess energy your panels produce.
How Long Solar Permitting Takes in Delaware, Maryland, New Jersey, and Pennsylvania
Permit timelines vary by state and even municipality. For example:
New Jersey's standard residential solar permit generally takes 10 to 15 business days in most municipalities. The state's Solar Instant Permit Program, available in 68 towns including Newark and Trenton, cuts that to three business days for pre-approved system designs.
Pennsylvania permit timelines range from same-day approval in Philadelphia through its EZ Permit program to 15 business days in cities like Harrisburg, with utility interconnection adding another two to five weeks on top.
Maryland jurisdictions vary considerably, with some reporting six to eight weeks during periods of high application volume.
Delaware timelines depend on your municipality and any backlog.
At Solair, we track both your building permit and utility interconnection application simultaneously, so neither is delayed while waiting on the other.
What Happens on Solar Panel Installation Day?
Installation is the fastest stage of the entire process. A crew of experienced technicians completes most residential systems in one to three days, depending on panel count and roof layout. Here’s a general overview of what you can expect.
How Solar Panels Get Mounted on Your Roof
The crew starts by anchoring all hardware into your roof rafters, not only the decking. On asphalt shingle roofs, they drill lag bolts into the rafters, slide metal flashing under the surrounding shingles at each penetration, and bolt aluminum rails to the stanchions. Each REC panel locks to those rails with tamper-resistant fasteners. On standing seam metal roofs, U-clamps attach directly to the raised seams, so no penetrations are necessary.
How the Electrical Work Gets Done
Each panel connects to its Enphase microinverter via weatherproof MC4 connectors. Conduit carries that power to your main electrical panel, where a licensed electrician installs a dedicated solar breaker. The crew then tests each panel for voltage output and confirms the microinverters are communicating with Enphase's Enlighten monitoring platform. The system doesn't go live yet: it needs to pass an inspection first, and you need written permission to operate from your utility.
What Happens After Solar Installation?
After installation, an inspector from your local building department will visit to verify that the system meets building, electrical, and fire safety codes. The inspection covers the following:
Wiring methods
Circuit protection
Grounding
Safety signage
Confirmation that the racking is securely attached to your roof
Once your local inspection is passed, your installer submits a Part 2 interconnection application to your utility requesting permission to operate. Some utilities send staff to your home for an on-site review of the completed installation. Others approve the system based on installation photos and documentation without a site visit. If your inverter or AC disconnect is inside your garage, you'll need to be home for the utility's review.
Residential permission to operate takes two to twelve weeks after installation, depending on your utility and system size. The average for most residential systems runs two to four weeks. Once your utility issues written permission to operate, your installer activates the system and walks you through the Enphase Enlighten monitoring platform so you can track your system's daily production.
What Happens After Your Solar Energy System Goes Live?
Once your solar system receives permission to operate from your utility provider, it can be officially activated. At this stage, your installer will turn the system on and confirm that all components are working as expected. You’ll also be introduced to your monitoring platform, which lets you track your system’s energy production in real time from a phone or computer.
In the first few weeks, it’s normal to check your system frequently. Monitoring tools usually show daily, monthly, and lifetime energy output, along with alerts if something isn’t performing as expected. This visibility helps confirm that your system is producing in line with projections based on your location and system size.
Your utility bill will also begin to reflect your solar production. If your system is connected through net metering, excess electricity generated during the day may be sent back to the grid in exchange for credits. These credits can then offset the energy you use at night or during lower-production months.
Maintenance requirements are generally minimal, but not nonexistent. Rain often helps keep panels clean, though in some cases (such as heavy pollen, dust, or debris buildup), occasional cleaning may improve performance. It’s also a good idea to visually inspect your system from the ground from time to time to make sure nothing appears out of place.
If your system includes equipment like microinverters or monitoring hardware, these components will continue to report performance data automatically. Should an issue arise, your installer or manufacturer may be notified through the monitoring system, allowing for prompt service if needed.
Streamline Your Solar Energy System Installation With Solair
From your first call to the day your system goes live, the full timeline from contract to permission to operate runs 60 to 90 days for most residential installations. The physical installation of your panels takes one to three days. Everything else, from site assessment and system design to permitting and utility interconnection, makes up the remainder.
At Solair Green Energy Advisors, we handle every stage of this timeline for you, from system design and permit applications to installation and utility coordination. We’ve been serving homeowners and businesses across Delaware, Maryland, New Jersey, and Pennsylvania for years. If you're ready to learn more about the benefits of solar, call us at 302-841-1108 or fill out our contact form for a free site assessment.
Additional Solar FAQS
How Much Does It Cost to Install Solar Panels?
The cost of installing solar panels depends on several factors, including the size of your system, the type of equipment used, and your location. A larger system designed to offset higher electricity usage will generally need more panels and a higher upfront investment. Equipment choices such as panel brand, inverter type, and mounting hardware can also affect pricing.
In addition, local labor rates, permitting fees, and utility requirements can influence the total cost. Many homeowners reduce their out-of-pocket expenses through incentives or financing programs. Reviewing your energy usage and property details helps determine the right system size for your needs.
Do Solar Panels Work During Power Outages?
Most standard solar panel systems are connected to the electrical grid, so they’ll shut off during a power outage. This safety feature prevents electricity from flowing back into the grid while utility workers are repairing lines. As a result, even if your panels are producing energy, your system won't supply power to your home during an outage.
To maintain power during outages, you would need a battery storage system or a backup power solution. (Batteries store excess energy generated during the day and can supply electricity when the grid is down.) The size of the battery system determines how long you can power essential appliances, so knowing your energy usage is important when adding backup capability.
How Long Do Solar Panels Last?
Solar panels typically have a lifespan of 25 years or more. Most manufacturers offer performance warranties that guarantee a certain level of output over time, usually around 80 percent or more of the original capacity after 25 years. This means your system will continue to produce electricity well beyond the warranty period, though at a slightly reduced rate.
In addition to the panels themselves, other components, such as inverters, may need replacement earlier. For example, microinverters or string inverters may have shorter lifespans depending on usage and environmental conditions. Regular monitoring and occasional maintenance can keep your system operating efficiently throughout its lifespan.
Sources
National Caucus of Environmental Legislators. 2026. “New Jersey Enacts Landmark Law to Boost Rooftop Solar Access & Affordability.” Accessed April 29, 2026. https://www.ncelenviro.org/articles/new-jersey-enacts-landmark-law-to-boost-rooftop-solar-access-affordability/
Enphase Energy. n.d. “Enlighten.” Accessed April 29, 2026. https://enlighten.enphaseenergy.com/
