A 3,500 square foot home in Louisiana typically uses about 1,691 kWh per month at the state average rate of 11.4¢/kWh (EIA). With 5.4 peak sun hours per day, most homeowners need a 12.6 kW solar system — roughly 32 panels at 400W. After the 30% federal ITC, net cost is about $26,400, with 13.1-year payback and $58,000+ in estimated 25-year savings.
Content roles: This page is your Louisiana-specific sizing decision for 3,500 sq ft. For national methodology and roof/orientation depth, see the 3,500 sq ft national guide. For bill-based sizing, see $300/month (~$193/mo equivalent in Louisiana). Policy depth: Louisiana solar data.
⚡ System Size
How Many Solar Panels for a 3,500 sq ft House in Louisiana?
Louisiana electricity rates and sun hours change panel count versus the US average:
System size (kW) = Annual kWh ÷ (Peak sun hours × 365 × 0.82)
For 3,500 sq ft in Louisiana:
Estimated monthly usage: ~1,691 kWh
Peak sun hours: 5.4 h/day
System size:12.6 kW (~32 × 400W panels)
Metric
Louisiana
US average
Rate
11.4¢/kWh
16.3¢/kWh
Sun hours
5.4 h/day
4.5 h/day
System size
12.6 kW
15.1 kW
Panels (400W)
32
38
Louisiana requires a smaller system than the national average for the same square footage. Use our solar system size calculator with your actual utility bills for a precise ZIP-level result.
Find your exact solar savings
Enter your ZIP code for a personalized estimate using your state's electricity rate and sun hours.
💰 System Cost
What Does Solar Cost for a 3,500 sq ft Home in Louisiana After the ITC?
At $3.00/W installed (SEIA 2026), a 12.6 kW system in Louisiana costs about $37,700 before incentives. The 30% ITC saves ~$11,310, for $26,400 net cost.
📈 Payback Period
How Long Is Solar Payback on a 3,500 sq ft Home in Louisiana?
A 12.6 kW system saving ~$2,013/year pays back in about 13.1 years after the ITC. At 3% rate escalation, 25-year utility spend totals ~$84,400 vs $26,400 net solar — $58,000+ lifetime advantage.
Solar vs utility company · 25-year comparison
Total cost of staying on the grid vs owning solar for a $300/month bill (national average assumptions).
Louisiana does not currently have an active solar tax credit. The previous Solar Energy Systems Tax Credit program ended in 2021. Louisiana’s low electricity rates (among the cheapest in the US at under 10¢/kWh) mean longer payback periods, though the federal 30% ITC still applies to all installations.
At Louisiana's average rate of 11.4¢/kWh and 5.4 peak sun hours, a 3,500 sq ft home (~1,691 kWh/month) typically needs a 12.6 kW system — about 32 panels at 400W. See the [national 3,500 sq ft guide](/guides/how-many-solar-panels-3500-sq-ft-house/) for methodology.
A 12.6 kW system in Louisiana costs roughly $37,700 installed before incentives. The 30% federal ITC reduces net cost to about $26,400. Louisiana does not currently have an active solar tax credit. The previous Solar Energy Systems Tax Credit program ended in 2021. Louisiana's low electricity rates (among the cheapest in the US at under 10¢/kWh) mean ...
At $26,400 net cost and ~$2,013/year in bill savings, simple payback in Louisiana is about 13.1 years.
Most Louisiana homeowners in this size range see **$58,000+** estimated 25-year savings vs utility power. Equivalent monthly bill: **~$193** — compare the [$300/month bill guide](/guides/solar-panels-300-month-electric-bill/) for bill-based sizing.
The US average needs a 15.1 kW system at 11.0-year payback. Louisiana needs 12.6 kW with 13.1-year payback at 11.4¢/kWh and 5.4 sun hours.
$300/month electric bill by state
System size and payback vary by electricity rate and sun hours — see your state.