What you'll need
- What's failing — panels, inverter, or both
- Current or target system size (4kW–12kW+)
- Inverter type preference (string or microinverters)
- Whether you need old panel removal, roof repair, or a monitoring upgrade
What you'll get
- Total replacement cost range — Panels, inverter, and add-ons
- Cost per watt — Compare against new-install pricing
- Removal & disposal estimate — For old panels taken off the roof
- Itemized cost breakdown — Panels, inverter, roof repair, monitoring
Solar replacement cost overview
Panels degrade about 0.5% per year and are typically warrantied to 25 years at 80–85% of original output. The federal residential solar tax credit (Section 25D) expired for expenditures after December 31, 2025, so most replacement work in 2026 does not qualify for a federal credit — check state or utility rebate programs and consult a tax professional.
Solar Panel Replacement Cost by Scope
| Replacement Scope | System Size | Cost Range |
|---|---|---|
| Panels Only | 6 kW | $9,600–$14,400 |
| Panels + Inverter | 6 kW | $15,000–$22,500 |
| Panels + Inverter | 10 kW | $25,000–$37,500 |
| String Inverter Only | Any size | $1,200–$2,800 |
| Microinverters Only | 6 kW (~15 panels) | $2,700–$3,900 |
The federal residential solar tax credit (Section 25D) expired for expenditures after December 31, 2025 — most 2026 replacement work does not qualify. Check state or utility rebate programs and consult a tax professional.
When to replace vs. repair
Solar panels are the most durable part of the system — they typically last 25–30+ yearsand degrade only ~0.5%/year. The inverter usually fails first: string inverters last about 10–15 years, while microinverters carry 20–25-year warranties. So the most common "replacement" is actually just an inverter swap, not the whole array.
- Repair / swap the inverter when panels are fine but production dropped after 10–15 years.
- Replace individual panels for physical damage (cracks, hot spots, delamination) — often covered under warranty.
- Replace the whole system when a 20+ year old array's output has fallen well below your needs, or you're re-roofing anyway.
Signs you need a replacement
- A steady, unexplained drop in monitored production beyond the normal ~0.5%/year.
- Visible damage — micro-cracks, brown "hot spots," delamination, or moisture under the glass.
- Repeated inverter faults or a red/blinking status light.
- The panels predate current standards and replacement parts are hard to source.
What you can reuse — and what to check
If the racking and wiring are in good shape, they can often be reused, which cuts replacement cost. But if you're replacing a whole aging system, it's usually worth upgrading to higher-wattage panels and modern microinverters at the same time. Always confirm what's still under warranty — many panel and inverter defects are covered for 25 and 12–25 years respectively. Note the 30% federal residential credit (Section 25D) expired after December 31, 2025, so it does not apply to 2026 replacements.
Replacement pricing depends entirely on scope. This calculator prices panels-only work at $1.60–$2.40/watt, a full panels-plus-inverter swap at $2.50–$3.75/watt (the same range as a new install), and inverter-only work as its own separate line — $1,200–$2,800 flat for a string inverter or $180–$260 per panel for microinverters. For a 6 kW (15-panel) system, those scopes span roughly $3,375 to $24,188.
Three different jobs, three different price bases
"Solar replacement" covers three distinct scopes this calculator prices separately rather than as variations on one number. Panels-only, keeping the existing inverter and wiring, runs $1.60–$2.40 per watt. A full panels-plus-inverter replacement runs $2.50–$3.75 per watt — the same base rate as a brand-new installation, because it largely is one. Inverter-only replacement is priced on its own basis entirely: a flat $1,200–$2,800 for a string inverter, or $180–$260 multiplied by your panel count for microinverters, with a 1.25× multiplier over string pricing reflecting the added per-panel hardware and labor.
Why the inverter is usually the reason for this page, not the panels
Panels themselves degrade slowly and predictably — about 0.5% of output per year, with a 25-year warranty typically guaranteeing 80–85% of original output at the end of that span. Inverters do not age nearly as gracefully: a string inverter typically needs replacement after 10–15 years, well inside a panel's warrantied life, which is why inverter-only replacement is such a common and comparatively inexpensive fix. Microinverters, distributed one per panel rather than centralized, tend to have longer service lives, which is part of what the higher upfront 1.25× multiplier is paying for.
This work does not qualify for a federal credit in 2026
Replacement and repair work is not exempt from the same cutoff that ended new installations' eligibility. Section 25D, the federal residential credit that once returned 30%, is not available for property placed in service after December 31, 2025 — and that in-service test applies to a replacement panel or inverter exactly as it applied to the original system. Most panel and inverter replacement work performed in 2026 gets no federal credit; check for a state or utility rebate program instead, and confirm with a tax professional if your situation is unusual (for example, a warranty-covered swap versus an out-of-pocket upgrade).
The three add-ons that aren't priced by watt or panel
Beyond the panel and inverter line items, this calculator prices three add-ons as flat ranges rather than scaling them by system size, because none of the three actually scales with wattage. Old-system removal and disposal runs $20–$50 per panel — for the 15-panel example above, $300–$750 — and covers safely taking down and hauling away the retired hardware, not just unbolting it.
Roof repair is a flat $800–$2,500 regardless of system size, because it prices the condition of the roof underneath the array, not the array itself — a leak or soft decking discovered when panels come off is the same repair whether the system above it was 4 kW or 12 kW. Monitoring system upgrades run a flat $300–$600, covering a new communications gateway or app-connected monitoring hardware when replacement panels or an inverter swap leave the old monitoring equipment incompatible.
| Scope | String inverter | Microinverter |
|---|---|---|
| Panels only | $9,600–$14,400 | $9,600–$14,400 (inverter type doesn't apply) |
| Panels + inverter (full replacement) | $15,000–$22,500 | $16,125–$24,188 |
| Inverter only | $1,200–$2,800 | $3,375–$4,875 |
Figures from this calculator's own module constants. Panels-only and full-replacement scopes are unaffected by inverter type except where the inverter is priced separately within the full-replacement split.
Matching the scope to the actual failure
The biggest cost lever on this page is picking the right scope in the first place, not negotiating within it. An inverter failure priced as a full system replacement — because a homeowner assumed "solar problem" meant "replace the panels" — can mean paying $15,000–$22,500 for work that a correct inverter-only diagnosis would have priced at $1,200–$4,875 depending on inverter type, a five-to-twelve-fold difference for solving the same underlying problem.
A qualified diagnosis before committing to a scope is worth the cost of a service call by itself: an installer or electrician can typically confirm whether output has dropped at the panel level (pointing to panel damage or degradation) or at the system level (pointing to the inverter) before any hardware is ordered, which is the difference between the top row of the table above and the bottom one.
Methodology
Per-watt and per-panel rates for each replacement scope, the inverter-type multiplier, and the removal/roof-repair/monitoring add-on ranges are the literal constants in this calculator's own module. Panel count is derived from system size at 0.4 kW per panel. The federal-credit exclusion follows the IRS residential credit expiry below.
Sources
- IRS — Residential Clean Energy Credit (Section 25D) — accessed 2026-09-05
About this calculator
How much does it cost to replace solar panels?
Replacing panels only (keeping the existing inverter and wiring) typically costs $1.60–$2.40 per watt, or roughly $9,600–$14,400 for a 6 kW system. A full panel + inverter replacement runs $2.50–$3.75 per watt, similar to a brand-new install, or about $15,000–$22,500 for the same 6 kW system.
How long do solar panels last before needing replacement?
Most solar panels are warrantied for 25 years and degrade only about 0.5% per year, meaning they still produce 80–85% of their original output at the end of that period. Many systems continue producing usable power well beyond 25 years, but efficiency losses, physical damage, or outdated technology often prompt replacement sooner.
Is it cheaper to replace panels or the inverter?
Replacing just the inverter is almost always cheaper than replacing panels. A string inverter replacement costs $1,200–$2,800 flat, while microinverters run $180–$260 per panel. Inverters typically fail before panels do — they last 10–15 years for string inverters versus 25+ years for panels — so an inverter-only replacement is a common and cost-effective fix.
Do I need a permit to replace solar panels?
In most jurisdictions, yes — replacing panels or the inverter typically requires an electrical permit and, in some cases, a building permit, especially if roof work is involved. Your installer usually handles permitting, but requirements vary by city and utility. Check with your local building department before work begins.
Does solar panel replacement qualify for a tax credit?
No — the federal residential solar tax credit (Section 25D, previously worth 30%) expired for expenditures made after December 31, 2025. Most panel and inverter replacement or repair work performed in 2026 does not qualify for a federal credit. Check for state or utility rebate programs in your area, and consult a tax professional for guidance specific to your situation.
Can I replace just a few panels instead of the whole system?
Yes, in many cases. If only a few panels are damaged or underperforming, they can often be replaced individually, especially with microinverter or power-optimizer systems where each panel operates independently. With a string inverter setup, mismatched panel ages or specs can slightly reduce efficiency, but partial replacement is still usually possible.