Louisville Solar Permit Guide
Louisville Gas and Electric (LG&E) territory · Jefferson County
Overview
GridPermit collects Kentucky residential solar and permitting facts directly from official sources (city, county, and state government sites, utilities, and public utilities commissions) and shows only what we can verify, with a confidence score and a link to where it came from. Nothing here is estimated or inferred beyond what's stated below. See our methodology for the rules this page follows.
Permit timeline
0–3 days
Per the City's own page: electrical permits are issued the SAME DAY a complete application is submitted (online applications receive a permit immediately). Simplified building permits for streamlined-eligible residential rooftop/ground-mount projects are turned around within 3 days or less when a complete package (including the licensed engineer/architect roof-support documentation) is submitted; most simplified building permits can be obtained the same day, with 4-5 business days anticipated for full review if not fully streamlined. Non-streamlined-eligible projects (and all commercial projects) instead require a full qualified review without the 3-day guarantee. No specific automated-review platform is named in the source material, so none is recorded here.
Battery/solar incentive program on record
No battery/storage incentive program is on record for this locality.
Permit fees
- Electrical permit: $50 (starting fee)
Per the City's own page: 'Fees for electrical start at $50.'
- Simplified building permit: $75 (starting fee, calculated based on the square footage area of the solar panel system)
Per the City's own page: 'Fees for... simplified building permits start at $75. The building permit fee is calculated based on the square footage are of the solar panel system.' Exact cost is confirmed during review and due at permit issuance.
Rebates
Not yet verified.
Utility and generation supplier
Utility
Louisville Gas and Electric (LG&E)
Generation supplier
Louisville Gas and Electric (LG&E) (utility)
No Community Choice Aggregator was found serving Louisville's residential solar customers this session; LG&E is recorded as both the distribution and default generation utility.
Interconnection
https://lge-ku.com/net-metering
Per LG&E and KU's own page: net metering is capped at 45kW system capacity. Two credit structures apply depending on enrollment date: NMS-1 (enrolled before 2021-09-24) credits excess generation in kWh to offset future usage; NMS-2 (enrolled on/after 2021-09-24) credits excess generation in dollars at the Kentucky Public Service Commission's set rate (6.9 cents/kWh for LG&E, 7.4 cents/kWh for KU, effective 2021-09-24), carrying over as a bill credit but never paid out in cash. The 5-step application process (requirements review, application with 3 attachments via email or mail, review/approval, installation with inspections, utility meter installation/activation) is typically fee-free for nearly all applicants.
Required documents
- Electrical permit application (required when: always, for all solar installations (ground-mount or roof-mount))
- Simplified Building Permit application, a scaled roof diagram showing panel location/number and roof framing (e.g., 2x8s at 16in with 12ft spans), and manufacturer specifications (system weight and attachment method) (required when: roof-mounted systems only (ground-mounted systems need only the electrical permit))
- Structural engineer analysis (required when: unique situations such as unusual roof framing or loading conditions, determined case-by-case)
- Certificate of Appropriateness (required when: properties in a historic preservation district or subject to Architectural Review Committee review)
- Documentation of existing roof specification's ability to support the installation, signed and stamped by a licensed KY Professional Engineer or licensed Architect (required when: required specifically for the streamlined/3-day permitting path)
Inspection steps
- After installation, an inspection is required and requested through Develop Louisville's Division of Construction Review 'Request an Inspection' webpage
- Applicants must pass an electrical inspection (roof- and ground-mounted systems) and, for roof-mounted systems, a building inspection as well
- Expect a wait of 3-4 business days for an inspection; times vary by staff workload and application complexity
- Inspections are not guaranteed within the 3-day streamlined permitting turnaround window
Eligibility constraints
- Property types: residential
- Max system size (AC): 45 kW
- Max system size (DC): Not yet verified.
- Max thermal capacity: Not yet verified.
- Program/pathway: Streamlined 3-day permitting path for residential rooftop and ground-mount systems meeting completeness/engineering criteria
- Other conditions:
- In residential districts, roof-mounted systems may not exceed 10 feet above the maximum height allowed by the underlying form district, and no system may be attached to a building's wall or side (per Land Development Code Section 4.3.16)
- Freestanding (ground-mount) systems may not exceed the maximum building height of the underlying form district, and alternative-energy systems/equipment may cover no more than 25% of the lot area
- Properties in a historic preservation district or Architectural Review Committee jurisdiction require a Certificate of Appropriateness; most ARCs discourage panels visible from a building's primary/street-facing elevation but will work with owners on placement
- The 45kW figure recorded here reflects the statewide LG&E/KU net-metering capacity cap, not a separate City permit-eligibility limit
Official contacts
- Develop Louisville, Division of Construction Review — Permits, official website
Need a solar installer who handles permits in Louisville?
EnergySage is an independent solar marketplace where you can request property-specific pricing from installers familiar with local permitting.
Compare quotes from solar installers →You'll continue on EnergySage's website. GridPermit has a partner relationship with EnergySage; this link is not currently tracked, and whether the partnership results in compensation to GridPermit has not yet been confirmed.
Sources
- Installing Solar in Louisville, Louisville Metro Government (government). Accessed 2026-08-13.
- Net metering for your home or business, LG&E and KU (utility). Accessed 2026-08-13.
Frequently Asked Questions
What utility serves solar customers in Louisville, Kentucky?
Louisville Gas and Electric (LG&E) is the interconnection and distribution utility for Louisville. The default electricity generation supplier is Louisville Gas and Electric (LG&E), a utility, separate from Louisville Gas and Electric (LG&E).
How long does a residential solar permit take in Louisville?
Per the City's own page: electrical permits are issued the SAME DAY a complete application is submitted (online applications receive a permit immediately). Simplified building permits for streamlined-eligible residential rooftop/ground-mount projects are turned around within 3 days or less when a complete package (including the licensed engineer/architect roof-support documentation) is submitted; most simplified building permits can be obtained the same day, with 4-5 business days anticipated for full review if not fully streamlined. Non-streamlined-eligible projects (and all commercial projects) instead require a full qualified review without the 3-day guarantee. No specific automated-review platform is named in the source material, so none is recorded here.
What documents are required for a solar permit in Louisville?
Commonly required documents include: Electrical permit application; Simplified Building Permit application, a scaled roof diagram showing panel location/number and roof framing (e.g., 2x8s at 16in with 12ft spans), and manufacturer specifications (system weight and attachment method); Structural engineer analysis; Certificate of Appropriateness; Documentation of existing roof specification's ability to support the installation, signed and stamped by a licensed KY Professional Engineer or licensed Architect.
Who do I contact about solar permits in Louisville?
Develop Louisville, Division of Construction Review — Permits.