How to Install Solar Panels: 7-Step Installation Guide

A solar installation is a chain of records. They show what was surveyed, what was approved, what was installed and what was tested. If the records disagree, fix the difference before you call the system complete.

This guide is for installers, project coordinators and customers who review the work. It follows the order of the job and adds the physical install steps. Each rule names its source. Wiring and structure details still come from the approved design, the product manuals and qualified people.

The installation process at a glance

DOE’s permitting and inspection guidance describes the US order of events. First you get a local permit. After the install, the local government inspects it. Then the utility connects the system to the grid, and it can start to generate power. Rules and fees differ by place. Another country may use different approvals.

How long does it take? A DOE consumer guide from August 2021 covers a home system. It says the install itself generally takes only a few days. Permits and inspections can take weeks to months, depending on local rules. Plan your schedule around the approvals, not the crew days.

1. Survey the site before you finalize the design

Check the roof condition, size, direction, obstructions and access. Look at the electrical connection, the meter setup, cable routes and equipment spots. If you only have a measurement from an image, record that it is an estimate.

The DOE guide says to confirm the roof can support panels. An installer, a roofing expert or a structural engineer can judge this. It also says to check shade and electricity bills. Online tools guess solar potential from remote data such as satellite images. For a detailed answer, an installer needs to visit the site.

Keep a survey record with:

• Measured roof and obstruction data, with photos.
• Roof condition and any planned repair or replacement.
• Access, lifting and work-area limits.
• The planned electrical connection and equipment spots.
• Known problems and who must fix each one.

Use a load analysis to split yearly energy needs from peak demand. Base the shading review on the surveyed site. The shading checks guide lists what to confirm before the layout is final.

2. Review the design and the structure

A sales proposal describes the planned system. It is not an approved construction design. Find the current drawing revision and the person who reviews it. Then check these against the rules that apply: the module and inverter choice, the string layout, the cable design, the protection, the bonding and the connection plan. A string is a line of modules wired in series. Bonding links metal parts so they stay at the same voltage.

For the roof, review the mounting plan and where the weight goes. Include wind, snow, fixings and ballast (weights that hold an array down). The UK installation standard MIS 3002 covers systems up to 50 kWp (2025 edition). It says a competent person must check that the roof structure can carry the array (3.9.3). It says a structural engineer must be asked if the roof is unusual or in doubt (3.9.5). The mounting-structure overview explains the parts.

Example of a design clash: A survey finds a roof vent where a module was planned. Moving that module can change the string layout, the shading and the access route. Record the change and review its effects. Update the drawings and the material list before the crew builds from a layout that no longer matches. This is a made-up example of the review process, not a customer project.

3. Handle permits and utility applications as separate tracks

Ask the local authority and the utility which approvals apply. A permit application receipt, a permit approval, a passed inspection and a utility approval are four different records. Label each one correctly.

For each submission, record:

Use the permit-ready drawing guide to plan the documents. The authority’s own checklist decides what goes in the packet.

Where permit work gets stuck, and what helps

DOE says paperwork errors and backlogs can delay permits. It says soft costs, which include permitting, make up about two-thirds of the total cost of a home system. The manual work behind this is the same on most jobs. You assemble the drawing and equipment packet. You answer correction requests. You resubmit, and you book the inspection.

Two habits cut the rework. First, track every submission in one register, as in the table above. Second, submit the version the crew will build. Then a late design change does not void an approved permit.

Some US places automate the review. SolarAPP+ is a platform for home solar and storage permits. The installer enters the system design. The platform runs automatic code checks. A code-compliant application gets a permit instantly. SolarAPP+ also gives an inspection checklist. Its site lists 350+ jurisdictions served and 150K+ permits issued. DOE’s page says SolarAPP+ automates solar and solar-plus-storage permitting for local governments. It only works where your local government has adopted it, so check the platform’s map.

4. Check delivered equipment and prepare the worksite

Match the delivered models and quantities to the reviewed equipment list. Record any substitutions, missing items and transport damage. A substitute module can change electrical limits, clamp zones and mounting sizes, even when its watt rating is close. MIS 3002 says that when a mounting system is certified with a named module, you may use only that module (3.5.4). All mounting parts must be approved to work together (3.5.3).

Keep the current manuals on site for the modules, mounting, connectors, inverter and any storage or protection equipment. MIS 3002 says to install all equipment to its manufacturer’s instructions (3.4.1). The materials and tools checklist lists what the crew needs on the roof.

OSHA is the US workplace safety agency. Its solar electrical guidance names shock, burn and arc-flash hazards. It tells workers to stay at least 10 feet from overhead power lines. Its lockout/tagout page says to cover the solar panels, as well as protect against the circuits.

For falls, OSHA says construction workers who could fall 6 feet or more need guardrails, safety nets or personal fall arrest. It says to lift panels to the roof with hoists, cranes or conveyors. It says workers should never climb a ladder while carrying a panel. The employer’s site safety plan sets the protective gear and work methods for the job.

5. Install mounting, modules and wiring

Build to the reviewed design and the equipment instructions. Take torque values, cable sizes and setbacks from the product manuals and the approved design. Do not copy them from another job. The steps below show the usual order.

Mounting and weatherproofing

Fix the attachments and rails to the structure the design reviewed. Seal every roof penetration the way the mounting maker says. MIS 3002 shows what a written standard asks for:

• On tile or slate roofs, notch or flash the tiles where needed so they do not leave gaps bigger than before the install (3.9.7). Flashing means sealing the joint with metal or a similar material.
• On metal roofs, check that the sheet is thick enough for the fixing bracket. Check that the sheet’s own fixings can carry the extra wind uplift (3.9.8, 3.9.9).
• On flat roofs with a mechanically fixed system on a solid deck, do a condition survey. Pull-out tests are advised (3.9.11).
• For ballast, use a friction coefficient of 0.3 in the sliding calculation, unless the material pair has been tested (3.9.12).

Modules

Lift the modules with hoists or cranes. Place them using the module maker’s clamp positions. On domestic roofs, MIS 3002 says modules should not sit within 400 mm of any roof edge (3.9.6). The exception is extra measures for wind uplift, snow and run-off. It also says the layout should allow access for maintenance and emergency crews (3.6.2). Options include walkways around the array, smaller blocks with corridors between them, and permanent cover over fragile parts such as skylights.

DC wiring and connectors

DC is direct current, the type of electricity modules make. The DOE’s PV cable management best practices says to route string cable away from sharp edges and rough surfaces such as roof shingles. Keep it away from moving parts and direct sun too. The same document reports two things.

• Under NEC 2020 and later, exposed cables must be supported and secured at intervals of 600 mm (24 in.) or less. The fittings must be listed for outdoor use (690.31(C)). The NEC is the US National Electrical Code.
• Some standard plastic cable ties have failed well before the end of an array’s life. Loose cables then rub and can cause a fault.

It cites the SolarGrade PV Health Report from Heliovolta. That report used 60,000 field inspection data points. Of the systems inspected, 61% had major or critical conditions. Of the DC distribution failures, 26% came from poor cable management.

For connectors, MIS 3002 asks installers to keep plug-and-socket connectors out of water for the life of the system (3.6.3). You can raise them out of standing water or add a drip loop. It also asks for the correct tools and steps when assembling them (3.6.4). Its note says wrong crimping and assembly tools are a major cause of failed connections and even fires. See the MC4 crimping guide.

Sunlit modules make DC voltage even when the AC supply is off. AC is alternating current, the type your grid supplies. Connect, disconnect and test PV wiring only under the approved procedure. It must cover every power source and the connected electronics. For more on protection, see the PV arc-fault detection guide.

Inverter and AC connection

The inverter turns DC into AC. Mount it where the maker’s instructions allow, with the clearances and ingress protection they ask for. Ingress protection (IP) is a rating for how well a box keeps out dust and water. MIS 3002 says an arc-fault detection function in the inverter must be on where it exists (3.6.7). An arc fault is a dangerous spark in a cable or joint.

Its note on ingress protection asks for cable entry at the bottom of enclosures, a drip loop and one cable per gland (3.6.5). It asks for AC cables sized to keep voltage drop low (3.6.8 note). It says 1% is practical on most small domestic systems, and up to 3% on larger systems or long runs. Connect to the network by the utility’s procedure. The interconnection application guide covers the US paperwork.

Earthing and bonding

MIS 3002 (3.3.2) lets the designer decide whether the array frame needs earthing, which means a safety connection to ground. If the designer chooses neither protective nor functional earthing, the reason must be recorded. The note says the decision tree it refers to would normally lead to one of the two. IEC 62446-1 lists earthing and bonding as an inspection item (clause 5.2.6). Its first Category 1 test is continuity of the protective earthing and bonding conductors (clause 6.1). Lightning and surge protection is a separate design choice. See the lightning protection guide.

Keep field changes traceable. Photograph hidden work, record part numbers and update the as-built drawings. An unexplained change should not vanish into a final drawing that implies it was always approved.

6. Commission with a defined test plan

Commissioning checks the finished system against the pass limits. Record the tests, the instruments, the conditions, the results, the defects and the person responsible.

IEC 62446-1:2016+A1:2018 covers handover documents, commissioning tests and inspection of grid-connected PV systems. IEC lists this edition as valid. The Category 1 procedures for all systems are listed below. Category 2 adds string I-V curve measurement and infrared inspection. The names come from the standard’s contents page, shown in the publisher’s preview.

• Continuity of protective earthing and bonding conductors.
• Polarity.
• String combiner box test.
• String open-circuit voltage.
• String current.
• Functional tests.
• Array insulation resistance test.

Run the Category 1 tests and record the results. A screenshot of power output is not a test record. Our solar safety compliance checklist explains each procedure and the documents to hand over.

Take test voltage, instrument ratings and pass limits from the standard, the equipment manuals and the project rules. Keep failed tests and the repair work in the record. A completed form with open defects is not an accepted installation.

7. Confirm connection status and hand over the records

Keep four statuses apart: install complete, commissioning complete, inspection passed and approval for normal grid operation. Confirm which export or metering setup applies. Not every project gets retail net metering. Permission to operate does not by itself create an incentive payment.

The handover package should include these items where they apply:

• As-built layout and circuit drawings.
• Equipment models, serial numbers and manuals.
• Permit, inspection and connection records.
• Signed commissioning results and proof that fixes are closed.
• Warranty registrations and service contacts.
• Monitoring access and who answers alerts.
• Operating and maintenance instructions, with any open work listed.

IEC 62446-1 clause 4 names the documents it expects. These are system data, a wiring diagram, a string layout and datasheets. They also include mechanical design information, emergency systems, operation and maintenance information, and test results with commissioning data. The project closeout package guide has a fuller list.

Monitoring shows that data is available. Explain what the portal reports and who looks into an alarm. Give the customer the maker’s operating instructions and a service contact. Do not ask them to troubleshoot live equipment.

SurgePV’s project design workflow covers roof modeling, layout, shading, energy yield, electrical workflow support and a bill of materials. Its outputs help the team hand work over. They do not replace approved engineering, field testing or approval by the authority. The installation steps hub links to related guides. The commercial solar permitting hub covers larger systems.

Frequently asked questions

What are the main steps in solar panel installation?

The main steps are site survey, design review, permits and connection applications, equipment check, installation, commissioning, inspection and handover. Installation itself covers mounting, modules, DC wiring, the inverter and AC connection, and earthing. The order and the approvals depend on the project and the country.

How long does solar panel installation take?

For a home, a DOE consumer guide says the install generally takes only a few days. Permits and inspections can take weeks to months, depending on local rules. Ask the installer for a schedule with milestones, open dependencies and who acts next.

Can a system operate immediately after panels are installed?

No. Finishing the install does not give approval for normal grid operation. Check the inspection, metering, protection and utility approval rules that apply. Any test run during commissioning must follow the permissions and procedures for the project.

What torque values and electrical test limits should installers use?

Use the instructions for your exact equipment, plus the approved design, standards and test procedure. A fastener size or a generic table from the internet is not enough to set torque, test voltage, instrument rating or pass limits.

What should the customer receive at handover?

The customer should receive the approvals, as-built drawings, equipment and warranty records, signed commissioning results, monitoring access, operating instructions and service contacts. List any open items and say who will finish them.

What order do you install solar panels in?

The usual order is mounting and weatherproofing, then modules, then DC wiring and connectors. Next come the inverter and AC connection, then earthing and bonding. Commissioning tests come last. Follow the approved design and the maker’s instructions for each step.

How do you reduce manual permit work on solar installs?

Track every submission in one register with the owner, the drawing revision, the date, the status and the next action. Submit the version the crew will build. In US places that use SolarAPP+, a code-compliant home solar application gets a permit instantly. DOE says paperwork errors and backlogs can delay permits.

What permits and grid connection steps are needed to install solar on an industrial facility?

The chain is the same as for any rooftop job. DOE describes a local permit before the work, a local inspection after it, and a utility connection before the system generates power. Ask the authority and the utility for the checklist for your system size. In the UK, MIS 3002 says an installation above 16 A per phase falls under G99, a network connection rule.