48E vs. 45Y: Which Credit Your Commercial Solar Job Actually Uses, and What It's Worth

Two federal credits, one rule of thumb: almost every commercial rooftop, canopy, or ground-mount project lands on 48E. Here's why, and what it pays.

Featuring Caleb Quaid, President, Clean Energy Help. Adapted from the SunSmart Engineering × Clean Energy Help × FlaSEIA panel, Commercial Solar in 2026. Watch the clip: "02 - 48E vs 45Y, Which Credit and What It's Worth.mp4".

The federal tax credit is usually the biggest line item working in your customer's favor on a commercial solar job, and there are two of them in play: 48E and 45Y. Contractors moving into commercial work often aren't sure which one applies. According to Caleb Quaid of Tampa-based Clean Energy Help, the answer is almost always the same one. Here's how the two credits work, what they pay, and why nearly every project you bid will run on 48E.

Two credits, two different ways to get paid

Both credits come out of the Inflation Reduction Act (the 2022 law), which took the old federal solar incentives and rebuilt them as "technology-neutral" credits for facilities placed in service after the end of 2024. Caleb laid it out plainly:

"The Inflation Reduction Act. There was always a production tax credit and an investment tax credit, but they modified them and created 48E and 45Y. 48E is an investment tax credit. Generally it's 30%. You spend $100,000, the taxpayer gets a $30,000 credit, so it's relatively straightforward."

That's the idea behind an investment tax credit (ITC). It pays a percentage of what you spend on the system, once, up front. 48E is the technology-neutral Clean Electricity Investment Tax Credit, and for most projects the base credit runs 30%. Spend $100,000 on eligible project cost, and the taxpayer earns a $30,000 credit. Your customer feels that number on day one.

45Y works differently. It's a production tax credit (PTC). Instead of paying a slice of your spend, it pays per unit of electricity the system produces, over a 10-year period:

"45Y is a production tax credit over 10 years. Rather than getting money up front based on how much you spend on the system, you get money for 10 years based on how much that system produces."

A PTC rewards generation, not installed cost. A site with great sun and a high-efficiency, well-oriented array can out-earn the up-front ITC over a decade, which is exactly where you tend to see it used.

Why commercial work almost always means 48E

The 45Y production credit pays off on enormous, optimized systems, and that's essentially the only place it lives. Caleb has seen it, but only at a scale most contractors will never touch:

"Very typically that's only done at sophisticated, large-scale ground-mount tracking systems at utility scale... I've seen [45Y] at utility scale, 70 megawatts; if you're doing small or even medium commercial scale, I've never seen it done. It's much more complex with a lot more reporting requirements."

A 70-megawatt tracking farm has the production numbers, the financial backing, and the staff to handle a decade of metering and reporting. A commercial rooftop, a parking canopy, or a typical ground-mount doesn't, and doesn't need to. For those jobs 48E is easier and usually pays more: one credit, calculated on cost, claimed up front, with far less ongoing paperwork.

So for the projects in this series, the rule of thumb is short. If it's commercial rooftop, canopy, or ground-mount, you're talking about 48E. 45Y is a utility-scale tool.

The choice comes down to scale and tax appetite

This isn't a line drawn in statute. It's a business decision. A project owner elects one credit or the other, and the right call depends on the project's scale, its expected production, and the owner's tax situation, meaning how much credit value they can actually use and how soon they want it. For most commercial customers, the up-front 30% of 48E wins on both simplicity and economics.

A few things worth knowing when you talk numbers:

• The 30% base on 48E is tied to prevailing wage and apprenticeship (PWA) rules. Projects under 1 MW are treated as meeting PWA automatically. A larger project that needs PWA and misses it can drop to a 6% base. Keep this general and verify per project.
• 48E can stack bonus adders on the base. A domestic content bonus adds 10% (taking 30% to 40%), an energy community bonus adds another 10%, and low-income adders apply on qualifying projects, so the credit can run well above 30%.
• Customers without tax liability, like governments, schools, and nonprofits, can use elective pay (direct pay) under IRA §6417 to receive the credit's value as a payment. Taxable owners who can't use the full credit can sell it through transferability under §6418.

These rules keep moving. The One Big Beautiful Bill Act, signed July 4, 2025, accelerated the phase-out for wind and solar and added Foreign Entity of Concern (FEOC) restrictions, and more IRS guidance was still expected as of the June 2026 webinar. Treat every percentage and threshold here as current but changing, and confirm the specifics with a qualified advisor before you put numbers in a proposal.

The bottom line

• 48E is an investment tax credit paid on cost. 45Y is a production tax credit paid on output over 10 years. Don't mix them up.
• 48E is generally 30% of eligible project cost. Spend $100,000, earn a $30,000 credit, claimed once.
• 45Y rewards production, not spend, and lives almost entirely at utility scale (think 70 MW tracking systems) with heavier reporting.
• Commercial rooftop, canopy, and ground-mount jobs almost always use 48E because it's simpler and usually pays more.
• Scale and tax appetite drive the choice, and 48E can climb past 30% with domestic content and energy community adders.

How SunSmart Engineering can help

SunSmart Engineering provides full-service engineering for solar and energy storage. We're Florida-based and work nationwide, so your commercial rooftop, canopy, and ground-mount projects get designed and documented to support the credit your customer is claiming. We help you bid with confidence and keep the engineering lined up with how the incentives actually work. Visit sunsmartengineering.com or call 866-786-8655.

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Educational information only. Not tax, legal, or engineering advice. Rules referenced (credits, FEOC, safe-harbor litigation, and the July 4, 2026 / December 31, 2027 dates) were current as of the June 2026 webinar and continue to change. Confirm current requirements with a qualified professional before acting.