Commercial Solar Depreciation and Tax Basis: Questions for Your CPA

Commercial solar depreciation is not a universal five-year write-off, a rebate, or a promised tax saving. As of August 10, 2026, a CPA must identify the tax owner and business use, classify each asset, establish acquisition, construction and placed-in-service dates, reconcile cost and credit basis, select the applicable system, method, recovery period, convention and elections, and plan for state adjustments and a later disposition. The installer’s job is to deliver reliable project facts and records—not calculate the customer’s return.

This guide is for a business owner, CFO, controller, facilities lead, property owner, nonprofit, public buyer, CPA, or tax counsel reviewing a commercial solar project in Connecticut, Massachusetts, or Rhode Island. Teamsun offers commercial solar assessment and installation, but this page contains no Teamsun tax advice, depreciation estimate, project basis, credit amount, customer tax rate, deduction value, or filing conclusion.

If your adviser needs a defined equipment, construction, commissioning, and cost file before answering the tax questions, request a commercial solar assessment. Teamsun can organize installer-side records within its role; the taxpayer and qualified advisers own tax classification, elections, return positions, and outcomes.

Direct answer: Give the CPA a version-controlled data room, not a sales-page percentage. It should reconcile executed price to asset-level costs, identify the owner and business use, prove when each asset was ready and available, connect any Section 48E determination to the correct basis adjustment, document federal and state differences, and keep a continuing register for replacements, sales, retirement, and recapture analysis.

Is commercial solar still five-year MACRS property in 2026?

Sometimes—but neither “all solar is five-year property” nor “solar is no longer five-year property” is safe. Public Law 119-21 removed one five-year classification for certain solar and wind energy property whose construction begins after December 31, 2024. It did not remove the separate five-year provision for qualified zero-emissions clean electricity facilities, property, and storage. A CPA must identify the exact Code clause and facility facts rather than classify the entire contract from the word “solar.”

The newest published IRS Instructions for Form 4562, revised in March 2026 for tax year 2025, flag that Section 70509 removed solar or wind energy property from the five-year definition under Section 168(e)(3)(B)(vi) for property beginning construction after 2024 (IRS Form 4562 instructions). The Congressional Research Service explains the important second half: Section 168(e)(3)(B)(viii), covering property that qualifies under the clean electricity provisions, was not removed, so zero-emissions property qualifying through that route can remain eligible for five-year recovery (CRS analysis of Public Law 119-21). The current statutory text should control the CPA’s analysis (26 U.S.C. Section 168).

Use this classification decision table:

CPA question	Evidence to supply	Unsafe shortcut
Which Section 168 clause applies to each asset?	Tax memorandum identifying the exact statutory provision	“Solar has always been five-year property”
Does the property meet a Section 48E qualified-facility or qualified-property definition?	B241 eligibility workpaper, ownership, facility map, asset list	“It makes zero-carbon electricity, so every cost qualifies”
When did construction begin for the relevant property or facility?	Adviser-approved construction-start file	Contract signature or deposit alone
Is a component separate building, roof, land, utility, storage, or other property?	Engineering design, invoices, use, ownership, and location	Assigning one life to the full EPC price
Does GDS or ADS apply?	Taxpayer status, use, financing, election, and statutory analysis	Copying a five-year percentage table from a proposal
What class life, recovery period, method, and convention apply?	CPA asset-class mapping and current Form 4562 instructions	Treating “MACRS” as one schedule

The IRS’s clean-energy cost-recovery page says certain qualified facilities, property, and storage placed in service after 2024 may be five-year MACRS property (IRS clean-energy cost recovery). “Certain” matters. It does not say that a roof replacement, building reinforcement, owner legal fee, financing charge, land, unrelated electrical upgrade, or every line in a turnkey contract shares that classification.

This page does not decide whether a system qualifies under Section 48E. The 2026 commercial solar tax-credit guide owns that eligibility, rate, construction, sourcing, bonus, transfer, and credit-recapture review. B242 begins with the adviser’s conclusion and builds the depreciation workpaper from it.

Which commercial solar records belong in the CPA data room?

The CPA needs a chain from legal ownership and executed contracts to asset-level cost, readiness, tax elections, and later changes. Build the data room while the project is designed and constructed; reconstructing it from a final invoice after commissioning invites unsupported allocations.

Use this folder and responsibility map:

Data-room folder	Minimum contents	Primary provider and reviewer
Entity and ownership	Legal names, tax IDs, ownership chart, site owner, system owner, lessee/host, lender and related parties	Owner/legal; CPA and tax counsel review
Contracts	EPC/purchase agreement, lease or PPA, site rights, financing, O&M, warranties, amendments, change orders	Owner, developer, installer, lender; legal/tax review
Scope and design	Drawing set, one-line, equipment and serial schedule, roof/ground/canopy scope, storage, interconnection boundary	Installer/engineer; owner and CPA review
Cost ledger	Schedule of values, invoices, purchase orders, proof of payment, owner costs, allowances, credits, rebates, grants and reimbursements	Installer and owner; CPA controls allocation
Construction timeline	Notices, custom manufacturing, delivery, installation, testing, correction, substantial/final completion	Installer/developer; tax counsel reviews dates
Readiness and acceptance	Commissioning reports, punch list, owner acceptance, meter records, utility authorization, monitoring operation	Installer, engineer, utility, owner; CPA concludes placed in service
Credit workpaper	Section 48E facility/property determination, Form 3468 basis, credit determined, transfer/elective-pay documents	Tax counsel/CPA; installer supplies facts only
Depreciation register	Asset ID, description, location, owner, use, cost basis, adjustments, date, class, method, convention, deductions	CPA-controlled register
State schedules	Federal-to-state modifications and separate Connecticut, Massachusetts, Rhode Island asset records	State tax adviser
Post-close changes	Repairs, improvements, replacements, casualty, retirement, sale, transfer, use/ownership changes	Operations/finance notify CPA and counsel

Name files so an outside reviewer can trace them. A useful convention is assetID_documentType_effectiveDate_version. Preserve the original, not only a spreadsheet transcription. Tie every schedule-of-values row to a contract or change order, invoice, payment record, physical asset or service, and accounting treatment.

Do not ask the installer to label amounts “tax basis” as though that settles the issue. Ask it to describe what was bought and built: equipment model and quantity, physical location, function, labor, engineering, utility work, roof or structural work, dates, payer, payee, and contract allocation. The CPA can then apply tax law to facts rather than reverse-engineer a tax position from marketing language.

Who owns and uses the property for depreciation purposes?

The party paying the electricity bill, owning the building, signing the EPC contract, holding legal title, and claiming depreciation may not be the same entity. Resolve tax ownership and business or income-producing use before discussing basis or bonus depreciation.

IRS Publication 946 says a taxpayer generally must retain the incidents of ownership to depreciate property. A business that merely leases property from another owner generally cannot depreciate the owner’s cost, although it may depreciate qualifying capital improvements it makes. The publication also requires business or income-producing use and excludes property used solely for personal activities (IRS Publication 946).

Give the CPA an ownership-and-use memorandum answering:

1. Which legal entity acquires or constructs each solar, storage, interconnection, roof, and electrical asset?
2. When and how does title pass for off-site, delivered, installed, and accepted equipment?
3. Does a lender hold security only, or do lease, PPA, tax-equity, partnership, service, or purchase-option terms affect tax ownership?
4. Which entity bears investment exhaustion, casualty, performance, O&M, residual-value, and disposition risk?
5. Is the property used in a trade or business, to produce taxable income, for a tax-exempt function, for personal purposes, or in a mixed-use activity?
6. What percentage or allocation method supports business/investment use for each asset?
7. Are there related-party, tax-exempt-use, tax-exempt-financing, foreign-use, imported, or other facts that could require ADS or restrict an election?
8. Which return and activity will hold Form 4562 and the annual deduction?

The commercial solar financing guide owns the cash/loan/lease/PPA transaction comparison. For depreciation, bring its ownership and responsibility conclusion into the tax file. Do not give a third-party host the project owner’s depreciation in an ROI model, and do not assume a lender becomes tax owner merely because it has collateral.

For a nonprofit or public entity, do not conclude “no depreciation” and stop. Its adviser should map the actual owner, any taxable project entity, lease or PPA counterparty, elective-pay structure, unrelated business activity, and state treatment. The commercial host’s economics and the asset owner’s tax deductions remain separate perspectives.

How should the CPA build commercial solar tax basis?

Start with source costs, allocate them to assets and activities, then apply adjustments in their statutory order. The signed contract price, book carrying amount, Section 48E qualified investment, federal depreciable basis, state basis, credit basis, and amount financed can all differ.

IRS Publication 551 says basis is generally cost and that a lump-sum purchase of multiple assets must be allocated among the assets to determine depreciation and later gain or loss. It also explains that adjusted basis changes as later events add or subtract amounts (IRS Publication 551). That principle makes a detailed schedule of values more useful than a one-line “turnkey solar system” invoice.

Use this schematic basis bridge. It contains no dollar value, tax rate, deduction, or personalized calculation:

Documented acquisition or self-construction cost by asset

+ CPA-approved capitalized direct and indirect costs

− amounts allocated to land, current expense, another asset, or another taxpayer

= preliminary cost basis by asset

× adviser-supported business/investment-use share

± grants, reimbursements, credits, deductions, prior adjustments, and other statutory items

= adjusted depreciable basis before expensing or bonus

− adviser-elected Section 179 amount, if applicable

− adviser-determined special depreciation allowance, if applicable

= remaining basis for regular MACRS or other depreciation

The bridge is a workpaper order, not a tax conclusion. The CPA should separately map at least these cost buckets:

Cost bucket	Installer-side evidence	CPA question
Modules, inverters, racking and controls	Model, quantity, serials, invoice, location, function	Which asset/unit and recovery classification?
Wiring, switchgear, transformers and meters	One-line, ownership boundary, invoice, useful function	Integral solar property, building system, utility property, or separate asset?
Battery storage	Model, capacity, controls, ownership and charging/dispatch design	Separate technology, facility property, or different recovery/election treatment?
Engineering and construction labor	Scope, invoice, work package and asset assignment	Capitalizable to which asset, current expense, or excluded transaction cost?
Interconnection and utility work	Study, agreement, invoice, point of ownership, reimbursement	Taxpayer-owned property, payment for utility work, Section 48E qualified investment, or other treatment?
Roof and structural work	Roofing drawings, condition report, reinforcement scope, useful life	Solar property, building improvement, repair, or separately classified asset?
Financing and transaction cost	Lender, legal, appraisal, tax, commitment and closing invoices	Interest, debt issuance, facilitative, capitalized, amortizable, or other treatment?
O&M, monitoring and warranty	Service term, prepaid amount, hardware/software split	Current service, prepaid expense, intangible, embedded asset, or capital cost?
Rebates, grants, insurance and reimbursements	Award, payment, restriction and tax documents	Income, basis reduction, credit interaction, or no adjustment under a specific rule?

Do not force the Section 48E basis schedule and depreciation schedule to match. Some cost may be depreciable but not part of qualified investment; some shared cost may require allocation; a building or structural component can have different recovery rules; and the Section 50 adjustment applies by reference to investment-credit property and the credit determined.

How does Section 48E change depreciable basis?

Section 50 provides a special basis-adjustment rule for an energy credit or clean electricity investment credit: only 50% of the credit determined is taken into account for the statutory basis reduction. That is not the same as saying every commercial solar project has “85% depreciable basis.” The actual percentage changes with the credit, the property to which it relates, allocation, ownership, other basis adjustments, and whether a credit is determined at all.

The current Code states the rule directly in Section 50(c) (26 U.S.C. Section 50). The current Form 4797 instructions also tell taxpayers to include the Section 50(c) downward adjustment when reconciling basis on disposition (IRS Form 4797 instructions).

A permissible schematic only, after the CPA confirms Section 50(c)(3) applies, is:

Property-specific Section 50 adjustment = 0.50 × adviser-determined Section 48E credit attributable to that property

Adjusted basis after this item = basis immediately before this item − property-specific Section 50 adjustment

Do not insert the EPC price into both sides of that formula. The credit may be based on qualified investment that is not identical to total depreciable cost. Do not subtract a credit from the contract price, call the result “net cost,” and then depreciate unreduced cost. Do not reduce basis twice because a proposal already displayed a net number.

Give the CPA a reconciliation with four independently sourced amounts:

1. gross contract and owner cost;
2. asset-level preliminary depreciable basis;
3. Section 48E qualified investment and credit determined from the B241 workpaper;
4. Section 50 and all other adjusted-basis entries, with Code section, date, owner, asset, and preparer.

Teamsun’s federal incentive overview is an internal orientation page, not tax authority. Use the current commercial Section 48E diligence guide and the taxpayer’s qualified advisers to determine whether a credit exists before adjusting any basis.

What date places a commercial solar asset in service?

Depreciation begins when property is ready and available for its specific business or income-producing use—not simply when a contract is signed, equipment is delivered, an invoice is paid, or panels are physically mounted. The CPA should conclude the date from the whole commissioning and readiness record.

IRS Publication 946 defines placed in service as ready and available for a specific use and gives an example in which delivered machinery was not placed in service until installed and operational (IRS Publication 946 placed-in-service guidance). A commercial solar file should therefore distinguish milestones instead of automatically selecting permission to operate or final payment.

Milestone	What it proves	What it does not prove alone
Equipment delivery	Property and date at site; possible title/custody evidence	Installed, tested, owned for tax, or ready
Mechanical completion	Physical installation under contract definition	Electrical readiness, safe operation, acceptance, or utility permission
Electrical completion	Defined electrical work completed	Commissioning, export authorization, monitoring, or owner readiness
Commissioning tests	Tested functions and exceptions	All punch-list items immaterial or owner accepted
Substantial/final completion	Contract milestone and remaining work	Tax readiness under every fact pattern
Owner acceptance	Customer’s contractual acceptance and exceptions	Utility interconnection or actual readiness if material work remains
Meter installation	Revenue/production measurement equipment installed	Authorization to energize or complete system functionality
Utility permission/authorization	Utility-approved operating or parallel status	Universal federal tax date by itself
First sustained operation	Operating evidence, output and monitoring	Whether readiness existed earlier or title/use was with another entity

Create one placed-in-service packet per asset or facility grouping selected by the CPA. Include photographs only as factual construction records, not decorative marketing; dated testing reports; open and closed punch-list logs; certificates; utility correspondence; monitoring screenshots; owner acceptance; warranty commencement; title passage; first operating data; and an adviser memorandum explaining the selected date.

This date also drives more than first-year depreciation. It can affect the tax year, applicable Form 4562 instructions, convention, bonus qualification, Section 48E filing, credit recapture window, financial reporting, state schedule, and disposition register. The installer documents events; it should not certify the federal tax date.

Does 100% bonus depreciation automatically apply in 2026?

No. Public Law 119-21 restored a 100% special depreciation allowance for certain qualified property acquired after January 19, 2025, but the taxpayer must still establish qualified property, acquisition and placed-in-service facts, ownership, basis, recovery period, exclusions, related-party/used-property rules, applicable depreciation system, and any election. A sales proposal cannot determine those facts.

The current IRS Form 4562 instructions say certain qualified property acquired after January 19, 2025 may receive the 100% special depreciation allowance. The listed category includes tangible MACRS property with a recovery period of 20 years or less. The same instructions say a taxpayer may elect a 40% allowance for specified property in the first tax year ending after January 19, 2025, or elect out for a class of property; those elections have filing and consistency rules (IRS Form 4562 instructions).

Before the CPA enters a bonus amount, answer this worksheet:

Bonus-depreciation gate	Required CPA conclusion
Qualified property	Exact Section 168(k) category and every exclusion
Recovery period	Asset-level classification, not “solar” shorthand
Acquisition	Acquisition date, binding-contract treatment, related-party status, original/used property facts
Construction	Who constructed for whom and which special acquisition rule applies
Placed in service	Date and tax year supported by readiness evidence
Depreciation system	GDS/ADS conclusion and any tax-exempt-use/financing or other restriction
Basis before bonus	Asset basis after business-use, Section 50, Section 179, and other required adjustments
Election	Default treatment, 40% transition election if available, or class-wide election out; return statement and deadline
Deduction usability	Entity, activity, taxable income, at-risk, passive, NOL, and other limitation analysis
State conformity	Separate CT, MA, RI or other state adjustment and tracking schedule

Bonus depreciation accelerates a deduction; it does not turn the deduction into a dollar-for-dollar credit or guarantee current cash. The tax effect depends on the taxpayer, entity, activity, taxable income, limitations, other deductions, and future years. The commercial solar ROI model should accept only the CPA’s dated annual after-tax cash-flow schedule and a zero-tax downside case.

Section 179 is a separate election with different property, income, dollar, phaseout, entity, leasing, and recapture rules. Do not treat it as a plug-in substitute for bonus depreciation. The newest Form 4562 instructions contain tax-year-2025 limits; a 2026 project must use the instructions and inflation-adjusted amounts applicable to its actual return year.

Do credit transfer or elective pay change depreciation ownership or basis?

They can affect cash timing and filing, but neither should be treated as a sale of depreciation deductions. The project owner and advisers must keep the Section 48E credit transaction, Section 50 basis adjustment, and asset depreciation schedule connected.

The IRS transferability FAQ states that a credit transferee cannot claim tax depreciation associated with the project; only a taxpayer with an ownership interest may claim that depreciation (IRS transferability FAQ). The 2025 Form 3800 instructions state that the Section 50(c) basis-reduction rule applies when a Section 48E credit is transferred. The owner should not retain unreduced basis merely because another taxpayer uses the credit.

The IRS elective-pay FAQ likewise says Section 50(a) and (c) apply to investment credits whether or not the owner makes an elective-pay election, and that the relevant credit reduces investment-credit-property basis as provided in Section 50(c) (IRS elective-pay FAQ).

Ask the CPA and counsel:

• Which entity owns and depreciates each asset?
• Which entity determines the Section 48E credit and basis adjustment?
• Was all or part of that credit used, carried, transferred, or elected for payment?
• How are transfer proceeds, fees, indemnities, credit recapture, and basis recorded?
• Does a partnership, disregarded entity, tax-exempt owner, lessee, or project company change the asset register or return owner?
• Which party must retain and furnish invoices, Form 3468, registration numbers, election statements, transfer agreements, and later event notices?

B241 owns whether transfer or elective pay is available. This page owns the control that carries its final credit determination into the owner’s depreciation register without shifting depreciation to the credit buyer or losing the Section 50 adjustment.

How should Connecticut, Massachusetts, and Rhode Island schedules differ from federal depreciation?

Do not copy the federal bonus-depreciation deduction directly to a New England state return. Current state materials show separate treatment, and the exact modification depends on state, entity, activity, filing year, and later disposition. Maintain distinct federal and state asset schedules from day one.

As of August 10, 2026, the latest generally available business-return instructions are primarily for tax year 2025:

State	Current official signal	CPA file to maintain
Connecticut	2025 CT-1120 materials require corporations to add back federal Section 168(k) bonus depreciation and use Schedule J to track Connecticut depreciation without that bonus (Connecticut corporation tax guidance, 2025 CT-1120 ATT instructions)	Federal Form 4562, CT asset basis, recovery period, convention, annual federal/CT depreciation and disposition history
Massachusetts	2025 Form 355 instructions say depreciation for corporate excise is computed using the federal method before enactment of Section 168(k) (Massachusetts Form 355 instructions)	Federal and Massachusetts basis/depreciation reconciliation by asset and year
Rhode Island	Rhode Island law disallows federal bonus depreciation under Section 168(k), and the Department of Revenue’s 2025 Public Law 119-21 report says taxpayers add federal bonus back on the applicable state schedule (R.I. Gen. Laws §44-61-1, Rhode Island H.R. 1 tax report)	Separate Rhode Island depreciation, addback/recovery and sale/disposition basis schedule

These are not personalized filing instructions. A pass-through owner, individual, tax-exempt entity, multistate group, combined return, utility, or fiscal-year taxpayer can use different forms and modifications. State forms for tax year 2026 may change after publication. The CPA should check the current return, instructions, law, conformity date, entity classification, apportionment, and disposition rules immediately before filing.

The practical control is simple: never overwrite federal basis with the state number. Store federal basis, CT basis, MA basis, RI basis, cumulative deductions, and adjustments in separate fields with source and date. A first-year federal deduction can create several years of state reconciliation and a different state gain or loss when the asset is sold.

What happens after commissioning, replacement, sale, or retirement?

The depreciation file must remain active after the first return. Replacing an inverter, removing modules for roof work, adding a battery, receiving insurance proceeds, retiring damaged equipment, selling the building, transferring the project entity, or ending business use can change basis, deductions, gain/loss, and credit recapture analysis.

Maintain this continuing asset register:

Field	Why it must remain current
Asset ID, description, serial/model and location	Identifies what was acquired, replaced, moved, or sold
Legal and tax owner	Connects deductions and disposition to the correct return
Acquisition/construction and placed-in-service dates	Supports qualification, convention, first year, and holding period
Federal and each state basis	Prevents state conformity adjustments from being lost
Section 50 and other basis adjustments	Reconciles credit and depreciation with later gain/loss
Method, recovery period, convention and elections	Supports annual Form 4562 and allowed-or-allowable depreciation
Annual and accumulated depreciation	Calculates adjusted basis and possible recapture
Improvement, repair, replacement, casualty, retirement and proceeds	Determines new assets, partial dispositions, deductions, and adjustments
Section 48E recapture-control dates	Flags sale/use/ownership events for Form 4255 analysis
Supporting document link and reviewer	Makes each entry auditable

IRS Form 4797 instructions require business-property sales and many partial dispositions to be reported and explain that amounts realized may need allocation among depreciable and other property. They also use depreciation allowed or allowable in the disposition calculation, so failing to claim a deduction does not automatically preserve basis (IRS Form 4797 instructions). Publication 544 supplies the broader sales and depreciation-recapture framework (IRS Publication 544).

Keep two recapture questions separate:

• Depreciation recapture and disposition gain/loss: depends on property character, adjusted basis, allowed-or-allowable depreciation, amount realized, holding period, and transaction; commonly reported through Form 4797.
• Investment-credit recapture: depends on Section 50 and the applicable investment-credit rules; Form 4255 can apply when property is disposed of or ceases to qualify during the recapture period.

Do not promise that a sale after five years has no tax consequence. The Section 48E credit recapture period and depreciation recapture are different regimes. A property sale can also allocate value among land, building, solar equipment, storage, contracts, and other assets. Notify the CPA and tax counsel before signing a sale, lease termination, buyout, equipment transfer, casualty settlement, repower, or removal agreement.

Need a project-side closeout list for the tax team? Request a commercial solar assessment. Teamsun can organize scope, equipment, cost, construction, commissioning, and warranty records; the owner’s CPA and counsel must decide basis, depreciation, elections, state adjustments, and disposition treatment.

Which questions should the buyer send the CPA before approving the project?

Ask for a written issue list before contract execution and an updated conclusion before the return is filed. A one-line email saying “solar gets MACRS” is not enough for a tax-dependent capital decision.

Use this 20-question agenda:

1. Which entity is tax owner of each asset, and what documents support that conclusion?
2. Is each asset used in a trade or business, to produce taxable income, for a tax-exempt use, or in mixed use?
3. What property units will the depreciation register use?
4. Which cost belongs to solar equipment, storage, interconnection, building, roof, land, software, service, financing, or another asset?
5. Which direct and indirect owner costs must be capitalized, amortized, or currently expensed?
6. What allocation method supports lump-sum and shared costs?
7. Which Section 168 clause, asset class, recovery period, method, and convention applies to each unit?
8. Does the Section 70509 removal of the legacy five-year route affect any property?
9. Does Section 168(e)(3)(B)(viii) apply through a qualified Section 48E facility/property determination?
10. Does GDS or ADS apply, and why?
11. What fact pattern and documents establish acquisition, beginning of construction, and placed in service?
12. Is any property eligible for the Section 168(k) special depreciation allowance, and which exclusions or elections apply?
13. Should the taxpayer use, modify, or elect out of bonus depreciation for the applicable class?
14. Is Section 179 available or useful, and what separate limitations, election, and recapture rules apply?
15. How do Section 48E qualified investment and depreciable basis differ?
16. What exact Section 50 adjustment applies by asset, and when is it recorded?
17. How do credit transfer or elective pay affect the owner’s basis, records, and cash-flow schedule?
18. What at-risk, passive-activity, NOL, interest, taxable-income, or other limits affect when the deduction produces value?
19. What separate Connecticut, Massachusetts, Rhode Island, and other state schedules are required?
20. Which sale, transfer, use change, replacement, casualty, or retirement events require immediate notice and which forms may apply?

Do not approve a tax-dependent ROI case until the adviser answers the relevant questions and the document owner is assigned. The commercial solar ROI calculator should receive annual tax cash flows from that workpaper; it should not calculate commercial solar depreciation from a default tax rate.

Commercial solar depreciation FAQ

Is commercial solar automatically five-year property?

No. Current law preserves a five-year route for certain qualified clean electricity facility/property under Section 168(e)(3)(B)(viii), while Public Law 119-21 removed a separate legacy energy-property route for post-2024 construction. The CPA must identify the applicable clause and classify each asset; the contract total does not get one automatic life.

Did Public Law 119-21 eliminate five-year depreciation for every solar project?

No. It removed the Section 168(e)(3)(B)(vi) classification for affected solar/wind property beginning construction after 2024. CRS explains that the separate Section 48E-related clause remains. A project-specific facility, property, construction-date, and classification review is required.

Does 100% bonus depreciation mean the project cost is refunded?

No. Bonus depreciation is a deduction from taxable income, not a dollar-for-dollar credit or cash reimbursement. Qualification, basis, election, activity, entity, taxable income, loss limitations, state conformity, and future disposition determine whether and when it has value.

Is a 2026 solar project automatically eligible for 100% bonus depreciation?

No. The current federal rule can allow a 100% special allowance for certain qualified property acquired after January 19, 2025, but each asset must meet the Section 168(k) requirements. The CPA must verify acquisition, placed-in-service, recovery-period, ownership, use, exclusions, and elections.

Is commercial solar depreciable basis always 85% of project cost?

No. That shortcut assumes a 30% credit, identical credit and depreciation bases, no other adjustments, and one property owner. Current Section 48E rates and qualified investment vary, while project costs may span several assets. Apply Section 50 to the credit actually determined for the relevant property.

Does permission to operate establish the placed-in-service date?

Not automatically. It is important evidence, but IRS guidance asks when property is ready and available for its specific use. Commissioning, unresolved work, title, acceptance, operating capability, utility authorization, and taxpayer practice should be reviewed together.

Can a PPA host claim depreciation on the provider’s solar system?

Generally, a user that does not retain the incidents of ownership cannot depreciate the owner’s cost. But leases, improvements, project entities, purchase options, and tax ownership require document review. Identify the tax owner rather than inferring from the roof or utility account.

Can the buyer of a transferred Section 48E credit also claim project depreciation?

No merely by buying the credit. The IRS transferability FAQ says only a taxpayer with an ownership interest in the project may claim tax depreciation; transferability does not transfer depreciation benefits.

Does elective pay avoid the Section 50 basis adjustment?

No. The IRS elective-pay FAQ says Section 50(c) applies whether or not an applicable entity makes the Section 6417 election. The owner and adviser must still calculate and record the correct property-specific adjustment.

Can roof replacement be included in solar depreciable basis?

Do not assume it can or cannot. Itemize the roof, structural, solar, and shared work. The CPA should determine whether each cost is a repair, building improvement, separate asset, integral property, or otherwise treated under the applicable capitalization and depreciation rules.

Do Connecticut, Massachusetts, and Rhode Island follow federal bonus depreciation?

Current official materials show modifications or disallowance for the cited business returns, so a separate state schedule is necessary. Entity type and filing year matter, and tax-year-2026 forms may change. The CPA should use the current state return and instructions when filing.

What happens when an inverter or module is replaced?

Notify the CPA. The work may create a new asset, repair, improvement, retirement, partial disposition, warranty recovery, insurance adjustment, or credit-recapture issue. Preserve the removed asset ID, original and replacement cost, dates, proceeds, warranty documents, and operating records.

Does skipping a depreciation deduction preserve basis for a later sale?

Not necessarily. IRS disposition forms use depreciation allowed or allowable in calculating adjusted basis and recapture. Have the CPA correct errors through the appropriate method rather than assuming an unclaimed amount remains available on sale.

How long should the commercial solar tax file be kept?

Keep records for as long as the CPA or counsel says they may be material to a federal, state, credit, depreciation, ownership, or disposition issue. Form 4562 instructions require supporting books and records while their contents may matter to tax administration; a long-lived asset can outlast the initial return and credit period.

What sources and limitations shape this guide?

This guide was researched on August 10, 2026. Federal conclusions rely on the current Code; Public Law 119-21 analysis; the latest published IRS Instructions for Forms 4562, 3468, 4797, and 4255; IRS Publications 551, 544, and 946; IRS clean-energy cost-recovery, transferability, and elective-pay guidance; and current Connecticut, Massachusetts, and Rhode Island official materials.

Representative exact-intent 2026 results commonly present a five-year schedule, an assumed 30% credit, an “85% basis,” 100% first-year depreciation, a tax-rate multiplication, and an immediate quote or calculator. Some say post-2024 solar lost five-year treatment; others say every commercial system remains five-year. Current IRS and congressional sources require the two statutory routes to be separated. Buyer discussions focus on whether the owner is genuinely conducting a business, whether residential or mixed-use property qualifies, and whether an installer-provided “CPA strategy” can be trusted. Competitor, software, and forum pages informed question coverage only; no outside tax rate, basis, deduction, recovery schedule, savings claim, customer result, or advice was adopted.

The live Teamsun sitemap, last modified August 7, 2026, contained no commercial solar depreciation article. The live federal incentive page broadly markets commercial tax benefits and is not tax authority. In the repository, B241 owns Section 48E eligibility and rates, B238 owns ROI modeling, B239 owns financing structures, B240 owns PPA contract diligence, and the commercial cost page owns gross scope. B242 uniquely owns the installer-to-CPA data room, asset classification, basis reconciliation, placed-in-service packet, federal/state depreciation register, and disposition notification workflow.

No Teamsun commercial asset register, customer basis schedule, CPA memorandum, Form 4562, federal/state depreciation reconciliation, Section 50 workpaper, placed-in-service conclusion, bonus election, transfer/elective-pay file, replacement record, sale, or recapture history was available for publication. None is implied. This article is educational and does not provide tax, legal, accounting, financial, engineering, or investment advice.

How can Teamsun prepare a CPA-ready commercial project file?

The useful deliverable is not a tax-savings promise. It is a traceable project record: who owns each asset, what was purchased, what it cost, when it became ready, which credit workpaper affects it, and how the register will be maintained after commissioning.

Contact Teamsun to request a commercial solar assessment. Bring the ownership chart, property records, utility data, proposal, target schedule, and your CPA’s questions. Teamsun can build the project-side scope and closeout list; your CPA and tax counsel must determine commercial solar depreciation, basis, elections, state adjustments, filings, and future disposition treatment.