US residential solar · 2026 data

Solar Panels for Modular Home

Q: "How many solar panels does a 1,500 sq ft modular home need?"

"A 1,500 sq ft modular home typically uses 7,500–9,000 kWh per year. At 4.5 average peak sun hours (roughly the U.S. average), that requires a 4.5–5.5 kW system — about 12 to 14 panels rated at 400 W each. In sunnier states like Arizona or Florida, 10–11 panels may suffice. In cloudier northern states, you may need 15–16."

Q: "Which is cheaper for a modular home — a solar loan or a solar lease?"

"A solar loan costs less over 20–25 years and lets you claim the 30% federal ITC (worth $4,000–$7,500 on a typical system). A solar lease requires no upfront payment but transfers the ITC to the leasing company and limits your long-term savings. Homeowners who qualify for a loan at under 7% APR almost always come out ahead compared to leasing over the full system life."

Q: "Is solar worth it for a modular home in a northern state?"

"It still pencils out in most northern states, but payback takes longer — typically 10–14 years versus 7–9 years in the Sun Belt. Many northern states offer additional incentives (New York's 25% credit, Michigan's net metering law) that narrow the payback gap. The 30% federal ITC applies regardless of location, reducing upfront cost by thousands everywhere in the U.S."

Q: "How long until solar panels pay for themselves on a modular home?"

"Most modular home solar systems reach payback in 8–12 years, depending on local electricity rates and peak sun hours. In high-rate states like California or Hawaii, payback can happen in as few as 5–7 years. In low-rate states like Louisiana or Oklahoma, it may take 13–15 years. Panel degradation of roughly 0.5% per year is negligible over that timeframe."

Q: "Can I put solar panels on a modular home roof?"

"Yes, in most cases. Modern modular homes are built to the same structural codes as site-built homes and can support standard solar racking systems. Asphalt shingle and metal roofs both accommodate solar mounting without reinforcement in most installations. Check your manufacturer's warranty documentation for approved penetration specifications before installation to avoid voiding your roof coverage. *Data sources: U.S. Energy Information Administration (EIA) — average residential electricity consumption 10,500 kWh/year and retail rate $0.17/kWh, 2026; National Renewable Energy Laboratory (NREL) — PVWatts peak sun hour data by location, panel degradation rate 0.5%/year; Solar Energy Industries Association (SEIA) — installed solar cost per watt $2.80–$3.50, net metering state policy tracker 2026; U.S. Department of Energy (DOE) / Lawrence Berkeley National Laboratory — solar home resale value $4/watt average; DSIRE — state solar incentive and rebate database; IRS — Investment Tax Credit (ITC) 30% rate under the Inflation Reduction Act through 2032.*"

SAVE

$0+

Over 25 Years

$15,000 Cost after ITC

11.0 yrs Payback

7.2 kW System size

Most homeowners need:

16–21 panels
7.2 kW system
$15,000 after tax credits
11.0 year payback

✓ Updated monthly ✓ NREL data ✓ Reviewed by solar experts ✓ IRS tax credit included

Updated June 9, 2026 · 9 min read ·By Mark Sullivan ·Reviewed by Green Energy Calculators Editorial Team

Calculate My System Size View State Data

Without solar vs with solar

25-year cost comparison for a $300/month US electric bill.

Without solar

25-year utility cost

$57,300

Rates rise ~3% per year (EIA avg.)

With solar

Net system cost

$15,000

After 30% federal ITC

Your savings

Difference

+$42,300

Estimated lifetime advantage

Author Mark Sullivan

Reviewed by Green Energy Calculators Editorial Team

Last updated Jun 9, 2026

Sizing formula kW = Annual kWh ÷ (Peak Sun Hours × 365 × 0.82)

Disclosure: This article contains affiliate links to Shop Solar Kits. If you purchase through our links, we may earn a commission at no extra cost to you. This does not affect our recommendations.

Most modular homes need between 8 and 20 solar panels to cover 100% of their electricity use — that works out to a 3 kW to 7 kW system costing $9,000–$21,000 before the 30% federal tax credit. The exact number of solar panels for a modular home depends on three variables that shift sharply from one homeowner to the next: your home’s annual electricity consumption in kWh, the average peak sun hours at your location, and the wattage rating of the panels you choose. Get those three inputs right and the math is straightforward; get them wrong and you’ll either overbuild and waste money or underbuild and stay dependent on the grid.

Modular homes are factory-built to tight tolerances, which gives them one real advantage here: their energy use is more predictable than stick-built homes of similar square footage. But they still span a wide range — a 1,200 sq ft single-section home in Arizona uses very different amounts of energy than a 2,400 sq ft two-section home in Michigan. This guide covers the sizing formula, typical 2026 installed costs, and the state-level factors that shift the panel count most.

How to Calculate Solar Panel Count for a Modular Home

The core formula has three steps, and none of them require a contractor quote to run.

Step 1 — Find your annual kWh use. Check your electric bills for the past 12 months and add them up. The U.S. Energy Information Administration (EIA) reports the average American household uses about 10,500 kWh per year, but modular homes built after 2010 typically run 15–25% leaner — call it 8,000–9,000 kWh annually for a well-insulated 1,600 sq ft unit.

Step 2 — Look up your peak sun hours. NREL’s PVWatts tool publishes location-specific solar resource data. Phoenix averages 5.7 peak sun hours per day; Seattle averages 3.5. That gap alone changes your required system size by more than 60%.

Step 3 — Apply the formula. Divide your daily kWh need by your peak sun hours to get the system size in kW, then divide by your panel’s watt rating (typically 400 W for modern residential panels) to get panel count.

Example for a 9,000 kWh/year home in North Carolina:

Daily need: 9,000 ÷ 365 = 24.7 kWh/day
Peak sun hours in NC: ~4.7
System size needed: 24.7 ÷ 4.7 = 5.25 kW
Panel count at 400 W: 5,250 ÷ 400 = ~13 panels

People often ask why solar quotes vary so widely for the same home size. The answer almost always comes down to this formula — specifically peak sun hours and assumed energy use. Two installers using different assumptions can quote 10 panels versus 16 for the same house. Running the formula yourself first gives you a solid sanity check on any proposal you receive. For more on this topic, see our guide to How Many Solar Panels for a Split-Level Home?.

Use our solar system size calculator to run this formula with your actual utility bills and zip code in under two minutes.

Bar chart showing solar panel count needed for modular homes from 1200 to 2400 square feet — **Solar Panels Needed by Modular Home Size (2026)** A 2,000 sq ft modular home typically needs 14 panels (400 W each) at 4.5 average peak sun hours. Source: NREL PVWatts, EIA 2026.

Find your exact solar savings

Enter your ZIP code for a personalized estimate using your state's electricity rate and sun hours.

Modular Home Solar System Cost in 2026 After the Federal Tax Credit

Installed solar costs for modular homes run $2.80–$3.50 per watt before incentives in 2026, according to SEIA market data. That puts a typical 5 kW system at $14,000–$17,500 installed. After the federal Investment Tax Credit (ITC) — currently 30% through 2032 under the Inflation Reduction Act — the net cost drops to $9,800–$12,250.

Modular Home Solar Cost by System Size (2026)

System Size	Panels (400 W)	Gross Cost	After 30% ITC	Est. Annual Savings
3 kW	8 panels	$8,400–$10,500	$5,880–$7,350	$480–$720
5 kW	13 panels	$14,000–$17,500	$9,800–$12,250	$800–$1,200
7 kW	18 panels	$19,600–$24,500	$13,720–$17,150	$1,120–$1,680
10 kW	25 panels	$28,000–$35,000	$19,600–$24,500	$1,600–$2,400

Savings assume $0.16/kWh average retail electricity rate (EIA 2026). Actual savings vary by utility rate and net metering policy.

Two costs that modular homeowners sometimes overlook: roof penetrations and electrical panel upgrades. Factory-built roofs are engineered to specific load specs, so installers occasionally need to reinforce mounting points — add $300–$800 for this. If your modular home has an older 100-amp panel, upgrading to 200 amps costs another $1,500–$3,000 but is often required for solar interconnection.

Is solar worth it without net metering? In states without mandatory net metering, you still save on every kWh you consume directly from your panels — typically 80–90% of what you generate during daylight hours. The payback period stretches by 2–4 years compared to states with full retail net metering credits, but the system still turns profitable over a 25-year lifespan in most U.S. locations.

Use our solar savings calculator to model your specific payback period with current utility rates in your state.

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).

Total utility payments

$57,300

Total solar cost (after ITC)

$15,000

Net savings

+$42,300

Avg. monthly difference

+$114/mo

See my savings →

How Peak Sun Hours by State Change Your Modular Home Panel Count

Where your modular home sits is the single biggest variable in sizing — more impactful than the home’s square footage or energy efficiency rating. A 5 kW system in Florida (5.5 peak sun hours) produces about 57% more electricity per year than the same system in Washington state (3.5 peak sun hours). The panel count difference for a 9,000 kWh/year home between those two states is 6–7 panels, worth roughly $2,500–$4,000 in upfront cost.

Panel Count by State for a 9,000 kWh/Year Modular Home

State	Avg. Peak Sun Hours	System Size Needed	Panels at 400 W	Net Cost (after ITC)
Arizona	5.7	4.3 kW	11	$8,500–$10,600
Florida	5.5	4.5 kW	12	$8,800–$11,000
North Carolina	4.7	5.25 kW	14	$10,300–$12,900
Ohio	4.2	5.9 kW	15	$11,500–$14,400
Michigan	3.8	6.5 kW	17	$12,700–$15,900
Washington	3.5	7.1 kW	18	$13,800–$17,400

NREL’s solar radiation data confirms that Sun Belt states require 30–40% fewer panels than the Pacific Northwest for identical homes — a meaningful difference in upfront cost and available roof space.

One nuance specific to modular homes: many are sited on rural lots where tree shading and roof pitch matter more than in dense subdivisions. If your modular home has a shallow 3:12 pitch roof (common on manufactured-style modules), panels lay flatter and produce slightly less in northern latitudes. A south-facing 4:12 to 6:12 pitch is ideal. Installers in Tennessee and Georgia frequently flag shading issues on modular builds near wooded lots — microinverters or DC optimizers mitigate those shading losses by 5–15%.

Horizontal bar chart comparing average peak sun hours per day across six US states — **Average Peak Sun Hours by State for Solar Sizing** Arizona’s 5.7 daily peak sun hours means homeowners need 38% fewer panels than those in Washington state (3.5 hours). Source: NREL PVWatts 2026.

Grid-Tied vs. Off-Grid Solar for a Modular Home: Which Pays Off?

Most modular homes connect to the utility grid, which makes a grid-tied system with net metering the default and almost always the more cost-effective choice. Under net metering, excess solar power you export earns credits that offset night-time grid purchases — effectively using the grid as a free battery. According to SEIA, 40 states plus Washington D.C. have mandatory net metering laws, making grid-tied systems the right fit for the vast majority of modular home locations.

Off-grid solar makes sense in a narrower set of scenarios: rural lots where a grid connection would cost $15,000–$50,000 or more in line extension fees, part-time cabins, or homeowners with strong energy independence goals. An off-grid modular home setup adds battery storage — typically 10–20 kWh of lithium capacity — plus a backup generator, adding $10,000–$20,000 to the system cost. For a ready-to-install path, pre-built off-grid solar kits from Shop Solar Kits range from 200W portable setups to complete 10 kW cabin systems — use code WAYSENG101 at checkout for an additional discount.

Grid-Tied vs. Off-Grid Solar: Key Comparison

Factor	Grid-Tied	Off-Grid
Upfront cost (5 kW)	$9,800–$12,250 (after ITC)	$20,000–$30,000
Payback period	7–12 years	15–20+ years
Works during outages	No (unless battery added)	Yes
Net metering eligible	Yes	No
Best for	Grid-accessible lots	Remote rural sites

For modular homes in subdivisions or rural areas within a mile of utility lines, grid-tied solar wins on ROI in almost every scenario. For true remote setups, the math shifts — and our battery storage calculator can help you model exactly when off-grid becomes the smarter financial choice.

How Long Until Solar Panels Pay for Themselves on a Modular Home?

The average payback period for residential solar in the U.S. runs 7–10 years, but modular homeowners often land closer to 8–12 years because many modular homes carry lower baseline electricity bills — meaning smaller annual savings to offset the upfront cost. DOE data shows the national average electricity rate in 2026 is approximately $0.17/kWh, but rates range from $0.10/kWh in Louisiana to $0.30+/kWh in California and Hawaii. Homeowners in high-rate states recover their investment significantly faster.

Three factors compress or extend your payback window most:

1. State and utility incentives beyond the federal ITC. Some states layer on additional tax credits (New York offers 25%, capped at $5,000), rebates, or sales tax exemptions on solar equipment. DSIRE at dsire.org maintains a current, searchable database by state and utility.

2. Your utility’s net metering rate. Full retail-rate net metering cuts payback times by 15–25% compared to utilities that pay only wholesale rates for exported power. Several states revised their net metering rules in 2023–2025, so verify your current policy before signing an installation contract.

3. Panel degradation over 25 years. Modern monocrystalline panels degrade roughly 0.5% per year, per NREL data — meaning a system installed today still produces about 87% of its original output after 25 years. That gradual decline is already baked into most installer payback projections, but worth confirming in any quote you receive.

Line chart showing 25-year solar cumulative cash flow with break-even at year 10 — **25-Year Solar Cash Flow for a 5 kW Modular Home System** After a $10,500 net investment (post-ITC), the system breaks even around year 10 and generates approximately $17,000 in net savings by year 25. Source: EIA electricity rate data, NREL degradation estimates 2026.

Every modular home solar project is ultimately a math problem with a handful of location-specific inputs. Once you know your annual kWh use, your state’s peak sun hours, and your utility’s net metering rate, the optimal system size becomes clear. Use our solar ROI calculator to project the full 25-year return on your specific system, factoring in panel degradation, electricity rate escalation, and your state’s net metering policy.

Frequently asked questions

Direct answers for US homeowners — sized for a $125/month electric bill.

How many solar panels does a 1,500 sq ft modular home need?

A 1,500 sq ft modular home typically uses 7,500–9,000 kWh per year. At 4.5 average peak sun hours (roughly the U.S. average), that requires a 4.5–5.5 kW system — about 12 to 14 panels rated at 400 W each. In sunnier states like Arizona or Florida, 10–11 panels may suffice. In cloudier northern states, you may need 15–16.

Which is cheaper for a modular home — a solar loan or a solar lease?

Is solar worth it for a modular home in a northern state?

How long until solar panels pay for themselves on a modular home?

Can I put solar panels on a modular home roof?

Same usage, bill-based guide

Your Modular Home target maps to roughly a $125/month electric bill nationally.

$125 $125/month electric bill guide Panels · cost · payback · by state →

Popular state solar guides

Electricity rates and incentives vary — see data for your state.

CA California 29.4¢/kWh · 5.8h sun TX Texas 13.8¢/kWh · 5.6h sun FL Florida 13.5¢/kWh · 5.7h sun AZ Arizona 13.2¢/kWh · 6.5h sun NC North Carolina 12.8¢/kWh · 5.2h sun NY New York 22.4¢/kWh · 4.3h sun MA Massachusetts 24.5¢/kWh · 4.2h sun CO Colorado 14.2¢/kWh · 5.5h sun

View all 50 states →

Popular utility companies

Solar rules and net metering vary by utility — not just by state.

PG&E California Duke Energy NC · FL · Midwest Florida Power & Light Florida Oncor Texas APS Arizona Georgia Power Georgia

Methodology & data sources

Calculation method: System size uses NREL PVWatts derate factor (0.82). Costs based on SEIA 2026 installed cost ($2.75–$3.20/W). Payback uses net cost after 30% federal ITC (IRC Section 25D). Savings assume full-retail net metering unless noted.

Official sources: EIA state electricity rates · NREL PVWatts · Energy.gov ITC guide · DSIRE incentives · SEIA market data · IRS Publication 5695.

All figures are estimates for educational purposes — not tax, legal, or investment advice. Consult a licensed installer and CPA for your situation.