Solar Installation Business: S-Corp vs. Sole Proprietorship Tax Comparison

By Yarik Yarosh, CPA ·September 5, 2026 ·4 min read

Written by Yarik Yarosh, CPA (US & Canada) September 5, 2026 · FL CPA license AC61704 · CPA Ontario

Solar installation is classified as electrical or specialty contracting. It is NOT a specified service trade or business (SSTB) under IRC 199A, so the full 20% QBI deduction is available regardless of income level. The entity structure decision (sole prop vs. S-Corp) depends on net profit, workers’ comp rates (5-12% for electrical/rooftop work), and whether the owner has employees. Solar businesses tend to have higher revenue and profit per job than many other trades ($15,000-$40,000 per residential installation), which pushes owners above the S-Corp break-even earlier.

✓Key takeaway

Solar installation S-Corp analysis:

Industry characteristics affecting the decision:

Revenue per job: $15,000-$40,000 (residential), $100,000+ (commercial)
Materials: 50-60% of revenue (panels, inverters, racking, wiring)
Workers’ comp: 5-12% of payroll (rooftop electrical work)
Licensing: electrician’s license or specialty solar license required in most states
Seasonality: moderate (spring through fall in northern states, year-round in southern states)
Growth trajectory: high (solar demand increasing year over year)

NOT an SSTB: Solar installation is a construction/electrical trade. It does not involve consulting, financial services, health, law, or any of the enumerated SSTB categories. The 20% QBI deduction applies fully at all income levels.

S-Corp break-even calculation:

At $80,000 net profit (8% workers’ comp):

Sole prop SE tax: $11,298
S-Corp: reasonable salary $45,000, WC $3,600, employer FICA $3,443, payroll costs $1,200, extra return $1,000
S-Corp total: $9,243
Savings: $2,055 (marginal)

At $120,000 net profit (8% WC):

Sole prop SE tax: $16,946
S-Corp: salary $55,000, WC $4,400, employer FICA $4,208, payroll $1,200, return $1,000
S-Corp total: $10,808
Savings: $6,138

At $200,000 net profit (8% WC):

Sole prop SE tax: $24,694 (capped at Social Security wage base for the 12.4% portion)
S-Corp: salary $70,000, WC $5,600, employer FICA $5,355, payroll $1,200, return $1,000
S-Corp total: $13,155
Savings: $11,539

Break-even: approximately $70,000-$90,000 net profit depending on the workers’ comp rate. Higher WC rates push the break-even higher because the S-Corp salary creates WC liability that doesn’t exist as a sole prop (sole props often exempt themselves from WC coverage).

What does a solar installer’s full tax picture look like?

Hypothetical example

Round numbers. A solar installation S-Corp. Revenue: $500,000 (20 residential installations at $25,000 average). Owner is the licensed electrician, has 2 W-2 employees. Single filer.

Revenue: $500,000

Expenses:

Materials (panels, inverters, racking, wiring): $275,000 (55%)
Employee wages (2 installers): $90,000
Employer payroll taxes (FICA on employees): $6,885
Workers’ comp (on employees + owner salary, 8%): $12,000
Owner’s W-2 salary: $60,000
Employer FICA on owner: $4,590
Insurance (GL + commercial auto): $8,000
Vehicle expenses (2 trucks, actual method): $18,000
Equipment and tools: $5,000
Marketing: $6,000
Software, permits, licensing: $4,000
Office and phone: $3,000
Total expenses: $492,475

S-Corp net income (K-1 to owner): $7,525 (low because the $492,475 in expenses includes the owner’s salary)

Owner’s total compensation:

W-2 salary: $60,000
K-1 distribution: $7,525
Total: $67,525

Owner’s taxes:

Federal income tax on $60,000 salary + $7,525 K-1 = $67,525 total income
Employee FICA withheld from salary: $4,590
Standard deduction: $15,000
QBI on K-1: $7,525 x 20% = $1,505
Taxable income: $67,525 - $15,000 - $1,505 = $51,020
Federal income tax: approximately $5,700
Total employee FICA: $4,590
Total federal tax: $10,290

Section 179 in a growth year: If the S-Corp buys a new work truck ($50,000, GVWR over 6,000 lbs) and $20,000 in equipment:

Section 179: $70,000
But the S-Corp’s net income is only $7,525 before the Section 179
Section 179 cannot create a loss for the S-Corp (limited to business income)
Maximum Section 179 usable: $7,525
Remaining $62,475: carried forward to future years, OR use bonus depreciation instead (which CAN create a loss)

Using bonus depreciation instead:

Bonus depreciation on $70,000: $70,000
S-Corp net income: $7,525 - $70,000 = ($62,475) loss
The ($62,475) loss flows to the owner’s K-1
Owner’s taxable income: $60,000 salary - $62,475 K-1 loss + adjustments
The loss offsets the W-2 salary (since the owner materially participates)
Net result: significant tax reduction in the equipment purchase year

This is why bonus depreciation (which CAN create a loss) is often preferred over Section 179 (which CANNOT) for S-Corp owners with low K-1 income relative to their equipment purchases.

Illustrative numbers only, not a real client and not advice for your facts.

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Cite this page

Yarik Yarosh, CPA. "Solar Installation Business: S-Corp vs. Sole Proprietorship Tax Comparison." Blue Cloud CPA, September 5, 2026. https://bluecloudcpa.com/guides/solar-installation-entity-structure-scorp

This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.