Accelerated Depreciation on Solar: A CFO's Guide

For a profitable business weighing a rooftop solar investment, the electricity savings are the obvious benefit - they show up on the monthly bill. But there's a second, less visible benefit that can materially change the economics of an owned solar system: accelerated depreciation. For a company that owns a qualifying solar asset, it can be an important tax consideration in a CAPEX solar project - and also one of the most commonly misunderstood, overstated, or incorrectly modelled. This guide explains what it is, why it matters, and — just as importantly — the conditions that decide whether your business can actually use it. It is general information, not tax advice; for tax years beginning on or after April 1, 2026, the relevant treatment is governed by the Income-tax Act, 2025 and the Income-tax Rules, 2026, and the specifics should always be confirmed with your own tax advisor.

Accelerated depreciation lets a business that owns a qualifying solar asset write off a larger share of its cost against taxable income in the early years, rather than spreading it evenly over the asset's life. Where the deduction is front-loaded, it can create a significant tax shield in the first year or two, improving the after-tax return and after-tax cash flow of a CAPEX solar project. But the benefit is conditional, not automatic: it applies only to businesses that own the asset (the CAPEX route, not OPEX/PPA); its immediate value depends on the company having enough taxable profit to absorb the deduction (though unabsorbed depreciation may carry forward, subject to the applicable rules); and the exact method, rate, and treatment depend on the current tax law and the regime the company is under. The real question isn't "what's the depreciation rate?" — it's "can our business actually use this benefit, and by how much?" That's a modelling exercise for your tax advisor, not a headline figure.

Here's how to think about it.

What is accelerated depreciation on solar?

For tax purposes, depreciation is a deduction that recognises the cost of qualifying capital assets over time; "accelerated" depreciation is a general term for treatment that brings a larger portion of that deduction into earlier years. For eligible solar assets, the applicable tax depreciation treatment can result in deductions being concentrated in earlier years compared with a simple straight-line allocation of cost — though the precise method and rate depend on how the asset and taxpayer fall within the applicable depreciation provisions. In this article, "accelerated depreciation" is used as a general description of front-loaded tax depreciation, not as a separate standalone statutory category. In India, renewable-energy equipment has historically been treated favourably in this respect, allowing an eligible business to deduct a substantial portion of a solar plant's value from its taxable income sooner rather than later. For tax years beginning on or after April 1, 2026, this sits under the Income-tax Act, 2025 and the Income-tax Rules, 2026 (earlier years remain under the previous law and transition provisions).

The financial value comes largely from timing. For assets depreciated under the written-down-value method, the deduction is generally front-loaded because it's calculated on the declining written-down value. The precise method can depend on how the solar asset and the taxpayer fall within the applicable depreciation provisions (for example, a power-generation undertaking may be treated differently from ordinary block-of-assets depreciation). But the underlying logic holds: getting more of the deduction early is worth more, because a tax saving today is worth more than the same saving spread over many years. For a profitable company that can use it, that front-loaded tax shield can meaningfully improve a solar project's early-year cash flow and after-tax return.

Two things to hold onto from the start, because online explanations often oversimplify them:

• The exact rate, method, and any additional depreciation are set by the prevailing tax law and can change; they also depend on conditions specific to your business, asset, and corporate tax regime. Treat any single headline percentage you see online with caution.

• The benefit's immediate value depends on having taxable profit to absorb the deduction — but where it can't be fully absorbed in a year, unabsorbed depreciation may carry forward, subject to the applicable rules. So a low-profit year doesn't necessarily mean the benefit is simply lost.

Why does accelerated depreciation matter for solar economics?

Because for a profitable, tax-paying business, depreciation can materially affect the after-tax economics of an owned solar system — yet it can be misunderstood or incorrectly modelled. Electricity savings are visible and recurring; the depreciation benefit is a front-loaded tax effect that many buyers underweight simply because it's less tangible.

Its impact shows up in two places:

1. After-tax return and cash flow. A large early-year tax shield returns cash to the business quickly, which can improve the project's after-tax cash flow and after-tax return — and may shorten the after-tax payback period (it doesn't change the physical energy savings or the pre-tax payback).

2. The after-tax cost of the asset. Effectively, the tax saving reduces the net after-tax cost of owning the solar plant, because part of the investment is recovered through reduced tax in the early years.

This is why two businesses buying the identical solar system can see very different after-tax economics: the applicable depreciation treatment may differ, and even where the underlying deduction is the same, the amount and timing of the benefit each can actually use may differ — depending on taxable profit, tax regime, and structure. The usable benefit, not the headline rate, is what matters. That distinction is the single most important thing a CFO should take from this topic.

Who can actually claim it - and who can't?

A business that owns the solar asset may be entitled to depreciation under the applicable tax provisions - but whether it can extract immediate value depends on more than ownership, which rules out two common situations. The eligibility logic, in plain terms:

• You must own the asset. Accelerated depreciation is a benefit of ownership. That means it's available under the CAPEX route (you fund and own the system) — not under OPEX/RESCO, where a developer owns the system and you simply buy the power. Where the developer owns the asset, the depreciation claim generally belongs to them (which can be one reason OPEX tariffs are competitive), not to the power purchaser — though the exact treatment depends on the legal and contractual structure. (This is a key input to the OPEX vs CAPEX decision.)

• Taxable profit affects the immediate value. The deduction creates immediate value when there's taxable income to reduce. A low-profit year yields less immediate benefit — but where depreciation can't be fully absorbed, unabsorbed depreciation may carry forward to later years, subject to the applicable rules. So it's not simply "no profit, no benefit"; it's a question of when the benefit is realised, which is exactly the kind of detail to model with your advisor.

• Ordinary vs additional depreciation are separate mechanisms. Beyond the base (ordinary) depreciation, the law provides for a separate additional depreciation with its own eligibility conditions — for example, tied to being engaged in specified activities such as manufacture/production or power generation, and to the qualifying new plant/machinery meeting statutory conditions. These are not one combined allowance, and additional depreciation may not apply to a given business or installation.

• The corporate tax regime matters. Which corporate tax regime a company has opted into can affect the availability of certain provisions (particularly additional depreciation) and related computations. A blanket figure quoted online may simply not apply to your company's situation.

The practical takeaway: the value of accelerated depreciation depends heavily on the taxpayer's structure, its ability to absorb the deduction (now or via carry-forward), and the applicable corporate tax regime — a profitable company going the CAPEX route with usable deductions gets the most from it. Knowing which camp you're in is step one.

Why you should be sceptical of "60% first-year" claims

Some solar marketing presents a large blanket first-year depreciation figure by combining a base rate and an "additional" depreciation. That combined number is not a universal benefit — and presenting it as one is misleading. Ordinary depreciation and additional depreciation are separate mechanisms with separate conditions; the additional component depends on the business, the asset, the activity, the applicable provisions, and the tax regime — and its availability has been affected by the corporate-tax-regime changes noted above. The date the asset is put to use and its classification can affect the first-year treatment too.

So when you see a confident "recover most of your investment in year one through tax" claim, treat it as a best-case scenario for a specific type of taxpayer, not a number your business can bank on. The honest position — and the one your CFO and auditor will respect — is that the depreciation benefit is real and can be substantial, but its size is specific to your company's tax profile and must be modelled on your actual numbers. Any credible proposal will show you the benefit as it applies to your business, with the assumptions stated, rather than a generic headline percentage.

This is the same discipline we apply to solar pricing and savings generally (see our cost guide): the reliable number is the one modelled on your facility and your finances, not a figure borrowed from a brochure.

How does depreciation interact with the rest of the solar decision?

It's one input among several - and it specifically shapes the CAPEX-vs-OPEX choice and the timing of a project. A few connections worth understanding:

• CAPEX vs OPEX. Because the depreciation benefit accrues only to the asset owner, a profitable business that can fully use it has a stronger case for CAPEX. A business that cannot make effective use of the deduction in the near term may place less value on that particular CAPEX advantage; a business that prefers to preserve capital may also prefer OPEX for financing reasons. Depreciation is one of the tax-related differences between ownership and third-party ownership — a company comparing CAPEX and OPEX should model the respective after-tax cash flows rather than treat depreciation as a standalone deciding factor. This is one of the core trade-offs in our OPEX vs CAPEX guide.

• Commissioning and use timing. Depreciation rules commonly treat the year an asset is put to use differently depending on how long it was in use during that year — including a rule that can reduce the first-year deduction where the asset is in use for less than a set number of days. So when a plant is put to use within the tax year can affect how much benefit falls in year one versus year two. Your advisor can tell you whether a change in the put-to-use date materially affects your first-year position.

• Other tax-computation rules. Other rules can also matter, including MAT where applicable. From tax year 2026–27, MAT treatment depends on the company's applicable tax regime and circumstances — so a large depreciation claim's interaction with minimum tax, and when the value of the deduction is realised, is regime-specific. This is precisely why it's a modelling exercise, not a rule of thumb.

None of these should be navigated from a blog post. The point of understanding them is to ask your advisor and your solar developer the right questions — not to self-calculate the benefit.

The bottom line for C&I buyers

Accelerated depreciation is an important — and often misrepresented — financial consideration in commercial solar. For a business that owns its system and can use the available deduction, the tax benefit can materially improve after-tax cash flow and after-tax returns, and may shorten the project's after-tax payback period. But it is conditional, not automatic: it requires ownership (CAPEX, not OPEX); its immediate value depends on the business's ability to absorb the deduction against taxable income (with unabsorbed depreciation potentially carrying forward); and it depends on the current tax law and the company's corporate tax regime. Ignore the blanket "60% in year one" headlines; the number that matters is the one modelled on your business's actual tax position. The right move is to treat depreciation as a real input to your solar decision — factored into the CAPEX-vs-OPEX choice and the project economics — and to confirm the specifics with your tax advisor, who can tell you not just the rate, but whether and to what extent your business can actually use it.

SustVest delivers rooftop solar under both CAPEX (you own the system and capture the ownership benefits, including depreciation where your business can use it) and OPEX/RESCO (no upfront capital, you buy the power) models — and we'll model the after-tax economics both ways for your specific situation, so the funding decision is made on your real numbers. Ranked #8 in CRISIL Intelligence's CY2025 Top 10 rooftop solar project-developer ranking (India Solar Rooftop Map, December 2025), with 84+ projects delivered across 13+ states (company-reported figures). Book a free site assessment to see both scenarios for your facility. This article is general information, not tax advice — please confirm all tax specifics with your own tax advisor.

Frequently Asked Questions

What is accelerated depreciation on solar? Accelerated depreciation is a general term for tax depreciation treatment that brings a larger portion of a qualifying asset's deduction into earlier years. For assets subject to the written-down-value method, the deduction is generally front-loaded because it's calculated on the declining written-down value, creating an early tax shield that can improve a CAPEX solar project's after-tax return. The precise method and treatment depend on the applicable tax provisions (for tax years from April 1, 2026, the Income-tax Act, 2025 and Rules, 2026) and should be confirmed with a tax advisor.

Who can claim accelerated depreciation on a solar system? A business that owns the qualifying solar asset may claim depreciation, subject to the applicable tax provisions. That means it applies under the CAPEX route (you fund and own the system), not OPEX/RESCO (where the developer owns the system and you buy the power). The immediate value depends on the business having taxable income to absorb the deduction — but where it can't be fully absorbed, unabsorbed depreciation may carry forward, subject to the applicable rules. Availability of certain provisions can also depend on the company's tax regime. Confirm the specifics with a tax advisor.

Can you claim depreciation on OPEX or PPA solar? Where the developer owns the solar asset under an OPEX/RESCO or similar third-party ownership structure, the owner's depreciation claim generally belongs to the developer rather than the power purchaser — the exact treatment depends on the legal and contractual structure, not just the label. You benefit instead through a lower per-unit power tariff, which may partly reflect the developer's tax benefit. If capturing depreciation yourself is a priority, that points toward the CAPEX route, assuming your business can use the deduction.

Is the first-year solar depreciation benefit really 60%? Be cautious with blanket "60%" claims. These usually add a base depreciation rate and a separate "additional" depreciation together, but the additional component is conditional — it depends on the business, the asset, the applicable provisions, and the tax regime the company is under, and may not apply at all. The safe approach is to have your tax advisor calculate the benefit that actually applies to your business rather than relying on a headline figure.

Does accelerated depreciation reduce the cost of solar? Indirectly, for a business that can use it. The early-year tax saving can reduce the effective after-tax cost of owning the solar plant and may shorten the project's after-tax payback period, because part of the investment is recovered through reduced tax. However, the benefit is only as valuable as the business's ability to absorb the deduction against taxable income (now or via carry-forward), so two companies buying the same system can see very different after-tax outcomes.

Should depreciation decide whether I choose CAPEX or OPEX? It should be one input, not the sole factor. A profitable business that can fully use the depreciation benefit places more value on that particular CAPEX advantage; a business that can't use much of it places less. The right choice depends on the company's capital position, tax profile, ownership preferences, and the full after-tax economics of both structures — ideally modelled both ways with your advisor.

Sources

• Income-tax Act, 2025 (in force for tax years beginning on or after April 1, 2026) — depreciation and additional-depreciation provisions; ownership and "put to use" requirements; unabsorbed-depreciation carry-forward; less-than-180-days rule

• Income-tax Rules, 2026 — depreciation method (written-down-value block-of-assets vs the separate power-generation treatment); solar power generating systems within the relevant depreciation schedule

• Income Tax Department transition guidance — repeal of the Income-tax Act, 1961 and its continued relevance for earlier tax years; MAT treatment by regime under the 2026 framework

• Industry commentary on solar depreciation in India (2026) — accelerated depreciation as a major C&I financial lever; the caution that blanket "40% + 20% = 60%" figures are conditional and not universal

• SustVest — CAPEX and OPEX delivery; models after-tax economics both ways; 84+ projects, 13+ states (company-reported figures); CRISIL Intelligence CY2025 #8 ranking

Note: this post is deliberately written as GENERAL EDUCATIONAL content and states NO specific depreciation rate, tax section number, additional-depreciation percentage, or ₹ savings figure. That is intentional — the treatment is genuinely conditional (method, rate, regime, additional-depreciation eligibility, 180-day and MAT interactions all vary), and stating a specific number as universal would be inaccurate. However, the post still makes substantive tax-law statements (ownership, eligibility, carry-forward, the 2025 Act, additional depreciation, MAT), so internal tax/CA review IS recommended before publishing — the absence of specific rates does not remove that need. A future tax-advisor-reviewed edition could add the current specific rate and a worked example as a separate, higher-liability piece.