Solar ROI Calculation for Commercial

Commercial solar buyers in India have a financial advantage that residential customers don't: Accelerated Depreciation (AD) under Section 32 of the Income Tax Act, 1961. A factory owner installing a 100 kW system doesn't just save on electricity, they claim 40% of the entire asset value as a depreciation deduction in Year 1, reducing taxable income and generating a substantial tax shield. For a business in the 22–30% tax bracket, this single benefit can recover 8–12% of the system cost before the first unit of solar power is even generated.

The residential ROI calculation (covered in detail in our companion guide on solar ROI calculation for residential systems) uses three variables: system cost minus subsidy, then bill savings. Commercial ROI is fundamentally different, the tax structure changes everything. This guide walks through a complete 100 kW example with a full ROI stack, and gives you the framework to replicate it for any commercial system size.

The Commercial Solar ROI Stack, five layers, one outcome

The Commercial Solar ROI Stack is the named framework for commercial solar financial analysis. Unlike residential ROI (which has one primary financial driver, bill savings), commercial ROI has five distinct income streams that must all be quantified before quoting payback to a business owner.

1. 1

   Layer 1: Annual electricity bill savings

   The same calculation as residential, solar generation × DISCOM tariff rate. For commercial consumers on HT (High Tension) or LT (Low Tension) industrial tariffs, the effective rate is typically ₹7–₹11/unit including demand charges and power factor penalties. This is often the largest single benefit layer.

2. 2

   Layer 2: Accelerated Depreciation (AD) tax shield, the biggest single benefit

   Under Section 32 of the Income Tax Act, 1961, solar power generating systems qualify for 40% Accelerated Depreciation in Year 1. The remaining 60% is depreciated in subsequent years at the applicable rate. For a business with taxable income, this creates a tax saving in Year 1 equal to 40% × system cost × effective tax rate.

3. 3

   Layer 3: Renewable Energy Certificates (RECs)

   Commercial solar plants above certain capacities are eligible to earn RECs through CERC-approved registry. Each REC represents 1 MWh of solar generation. RECs trade on IEX (Indian Energy Exchange) and PXIL at prices that have ranged from ₹1,000–₹2,000 per certificate in recent years. For a 100 kW system generating ~1,400 units/day, annual REC income can be ₹50,000–₹1,20,000.

4. 4

   Layer 4: Net metering / export income

   For commercial sites where solar generation exceeds daytime consumption (e.g., manufacturing plants that run single shifts), surplus power is exported to the grid. The credit rate for commercial consumers is typically lower than the retail tariff, approximately ₹2.50–₹3.50/unit, but still adds meaningfully to the ROI stack.

5. 5

   Layer 5: Financing cost (subtract this if taking a loan)

   If the business takes a commercial solar loan (typically at 9–12% interest), the annual interest expense must be subtracted from the ROI stack. However, interest on a business loan for a productive asset is itself tax-deductible, so the after-tax financing cost is lower. Many commercial buyers use a mix of their own capital and debt to optimise the AD benefit.

40% Accelerated Depreciation explained, how it works, who qualifies

Accelerated Depreciation (AD) for solar assets is authorised under the Income Tax Act, 1961, as amended by the Finance Acts and Income Tax Department circulars. The key provisions:

Under Schedule II of the IT Act and the depreciation table notified by the CBDT, renewable energy generating equipment (including solar power generating systems) qualifies for 40% depreciation in the first year under the Written Down Value (WDV) method.

This means: if you install a ₹55 lakh solar system, you can claim ₹22 lakh (40% of ₹55 lakh) as a business expense in Year 1. If your company is in the 25% tax bracket, this generates a tax saving of ₹22 lakh × 25% = ₹5.5 lakh in Year 1 alone, without any reference to electricity savings.

In Year 2, the remaining book value (₹55 lakh − ₹22 lakh = ₹33 lakh) is again depreciated at 40%, giving ₹13.2 lakh in Year 2 depreciation. This continues until the asset is fully written down.

Who qualifies for Accelerated Depreciation on solar? Any Indian company, partnership firm, LLP, or proprietorship that:

• Owns the solar system (not on a PPA/lease arrangement where ownership stays with the developer)
• Uses it for business purposes (not a residential home)
• Is registered under the Income Tax Act and files regular returns
• Purchases and commissions the system in the financial year of the AD claim

Full 100 kW system ROI breakdown, working example

Let's run the complete Commercial Solar ROI Stack for a 100 kW rooftop system on a manufacturing plant in Pune (MSEDCL zone). The buyer is a company in the 25% effective tax bracket.

The full 100 kW calculation:

System details: 100 kW capacity, 182–186 kWh/day generation (MSEDCL zone, 5.0 peak solar hours, 0.80 PR), 365 days/year = approximately 66,430 units/year

Layer 1, Annual bill savings: Commercial MSEDCL LT tariff for manufacturing at high consumption levels = approximately ₹8.00/unit effective (including demand charges). 66,430 units × ₹8.00 = ₹5,31,440/year (approximately ₹5.3 lakh/year in bill savings)

Layer 2, AD tax shield Year 1: ₹55,00,000 × 40% = ₹22,00,000 depreciation. Tax saving at 25% = ₹5,50,000 (Year 1 only, but subsequent years continue smaller amounts)

Layer 3, REC income: If the plant registers for REC under CERC regulations and the site is in MSEDCL area, it can generate approximately 66 RECs/year (66 MWh). At ₹1,500/REC = ₹99,000/year (subject to REC market conditions)

Layer 4, Export income: Assuming 10% of generation is exported (6,643 units at ₹2.75/unit MSEDCL net metering credit) = ₹18,268/year

Layer 5, Financing cost: Assuming full own-fund (no loan), financing cost = ₹0

Year 1 total financial benefit = ₹5,31,440 (savings) + ₹5,50,000 (AD) + ₹99,000 (RECs) + ₹18,268 (export) = ₹11,98,708

Net investment cost = ₹55,00,000

Year 1 payback fraction = ₹11,98,708 / ₹55,00,000 = 21.8% recovered in Year 1

Simple payback (AD-adjusted) = ₹55,00,000 − ₹5,50,000 (AD benefit as effective capital reduction) ÷ ₹6,48,708 (Years 2+ annual benefit without AD) = ₹49,50,000 ÷ ₹6,48,708 = 7.6 years if only using recurring benefit post-AD. But including Year 1 total ≈ 2.8–3.2 years payback.

The payback calculation becomes more intuitive when you think of it this way: the ₹5.5 lakh AD benefit in Year 1 is money you receive from the government (as reduced tax liability) immediately, effectively making the net capital outlay ₹49.5 lakh instead of ₹55 lakh. At ₹13.5 lakh per year in bill savings alone, simple payback on the adjusted capital is approximately 3.7 years, or under 3 years when REC and export income are included.

For more on the installed cost components in a 100 kW system, see our detailed 100 kW solar price guide. For smaller commercial systems, see 10 kW solar price.

Accelerated Depreciation vs PM Surya Ghar, choosing the right vehicle for commercial buyers

Commercial rooftop solar buyers have a choice: go through PM Surya Ghar (which requires residential end-use and limits to 3–10 kW per connection in most states) or install as a commercial asset and claim AD. These are mutually exclusive for pure commercial sites.

For commercial buyers who also own residential property, they can pursue both routes simultaneously, PM Surya Ghar on their residence and the AD route for the business premises. The two benefits stack independently.

For more on GST rates for commercial solar EPC contracts (the 12% rule), see our guide on GST on solar systems in India. For the solar panel-specific tax treatment, see GST rate on solar panels.

Commercial solar tariff comparison, why commercial buyers save more per unit

Commercial and industrial electricity consumers in India typically pay higher effective tariffs than residential consumers. This is driven by demand charges (a fixed monthly charge per kVA of sanctioned load), time-of-day pricing on HT connections, and power factor penalties for loads that draw reactive power.

The effective rate including demand charges is the right number to use for ROI, not just the energy charge on the tariff schedule. A factory paying ₹6.20/unit in energy charges but also paying ₹80,000/month in demand charges for a 200 kVA load is effectively paying much more per unit when demand charges are spread across consumed units. Solar reduces the units drawn from the grid, which reduces both energy charges and, in some tariff structures, helps reduce the measured maximum demand (if solar covers peak loads), lowering demand charges too.

RECs, who can earn them and how to get started

Renewable Energy Certificates (RECs) are market-based instruments issued by CERC to recognise renewable energy generation. Commercial solar plant owners who are eligible can register with CERC-approved registry bodies and earn RECs for every 1 MWh of verified solar generation.

The primary use case for RECs is compliance with Renewable Purchase Obligations (RPOs), state electricity regulators require distribution companies, open access consumers, and captive power plants to source a minimum percentage of their power from renewable sources. Those who cannot generate renewable power themselves can buy RECs from those who can. According to MNRE, India's renewable energy targets under the National Electricity Plan require significant RPO compliance from obligated entities through 2030, ensuring sustained demand for RECs.

Who can register for RECs: Solar plants installed on commercial premises, grid-connected through the DISCOM net metering connection, with capacity above the threshold set by CERC (generally 1 kWp and above for solar). The plant must be registered on the CERC REC registry. Recent data from IEEFA (Institute for Energy Economics and Financial Analysis) shows commercial solar REC registrations grew by over 40% year-on-year in 2024–25 as more businesses became aware of the additional income stream.

Who cannot: Plants registered under PM Surya Ghar or other subsidy schemes that have already received government funding. Subsidy recipients cannot also earn RECs, it's one or the other.

For commercial EPC owners quoting 50–500 kW systems to businesses, adding the REC income projection to the proposal differentiates your pitch from competitors who only show bill savings. Even at ₹1,000/REC (the lower end of recent market prices), a 100 kW system generating ~66 RECs/year adds ₹66,000/year, a 5-year total of ₹3.3 lakh that most competitors' proposals don't even mention.

ROI under different financing scenarios, owned vs loan

Building the commercial ROI into your sales proposal

The commercial solar ROI Stack, when presented in a proposal, does something powerful: it reframes the conversation from "cost of solar" to "return on investment." A factory owner who sees ₹5.5 lakh coming back in Year 1 tax savings on a ₹55 lakh investment isn't thinking "this is expensive", they're thinking "this is a business decision I need to approve this quarter to get the full-year AD benefit."

The timing angle matters: AD is available only if the system is commissioned in the same financial year. A commercial buyer who delays from December to April loses an entire year's AD benefit. This creates genuine urgency without any artificial pressure from your sales rep.

For how to structure ROI in your proposals, see how to show ROI in a solar proposal and solar proposal payback period best practices. For the residential ROI equivalent, see solar ROI calculation for residential systems.

The cost structures for commercial systems at different sizes, plus the GST treatment at 12%, are covered in solar installation cost breakdown and solar cost per watt in India.

How QuickEstimate helps EPC teams close commercial deals faster

For Priya, the ops lead at a 40-person Pune EPC, the problem isn't understanding the AD benefit, it's making sure all 15 sales reps present it consistently and correctly. One rep shows AD, another doesn't. One uses ₹8/unit commercial tariff, another uses ₹6. The proposals look different, the payback numbers don't match, and Priya spends Monday mornings fixing versions before they go out.

QuickEstimate's Proposal Generator locks in the commercial ROI template, AD calculation, REC projection, correct GST at 12%, commercial tariff by DISCOM, and gives every rep the same output. The owner sees one consistent story from every proposal. Priya sees the pipeline in Pipeline Management without chasing status updates.

• Proposal Generator, Commercial ROI Stack template with AD calculation pre-built; correct 12% GST; DISCOM-specific tariff settings.
• Pipeline Management, Track commercial deals by system size, tariff zone, and AD eligibility; see where your ₹1 crore+ deals are in the pipeline.
• Sales Reports, Monthly revenue by customer category (residential vs commercial) so your ops lead can see which segment is driving margin.

What to do this week, for your EPC

1. 1

   Add the AD benefit calculation to every commercial proposal you send this week

   Take your next 3 commercial proposals in the pipeline. Add a row showing: "Year 1 Accelerated Depreciation tax benefit (40% × system cost × 25% tax rate) = ₹X." Track whether this changes the conversation, most commercial buyers haven't been shown this number by a competitor.

2. 2

   Create an urgency window around the March 31 financial year deadline

   AD is earned in the year of commissioning. A commercial buyer who commissions by March 31 gets the full 40% AD that financial year. Use this in your January–March outreach: "Commission by March 31 and claim ₹5.5 lakh tax benefit this year." It's not a manufactured deadline, it's a real one.

3. 3

   Ask your CA to confirm the AD rate and current depreciation table for solar

   The 40% AD rate has been consistent for several years, but Finance Acts occasionally revise depreciation schedules. Confirm the current rate from your CA before quoting the AD benefit to commercial customers, and always caveat in the proposal that "tax benefits are subject to your applicable tax status; consult your CA for personalised advice."

Frequently asked questions

What is Accelerated Depreciation for solar in India?

Accelerated Depreciation (AD) for solar power generating systems in India is a provision under Section 32 of the Income Tax Act, 1961. It allows businesses that purchase and own solar systems to claim 40% of the asset's value as a depreciation deduction in the first year, with remaining value depreciated in subsequent years. For a business in the 25% tax bracket installing a ₹55 lakh system, this generates ₹5.5 lakh in tax savings in Year 1. AD applies to companies, partnerships, LLPs, and proprietorships that use the solar plant for business purposes.

Does PM Surya Ghar subsidy apply to commercial rooftop solar?

PM Surya Ghar Muft Bijli Yojana is designed for residential rooftop solar consumers and does not apply to commercial or industrial properties. Commercial sites are not eligible for the central ₹78,000 subsidy. However, commercial buyers can claim 40% Accelerated Depreciation under the IT Act, which provides a larger financial benefit than the residential subsidy for businesses in the 22–30% tax bracket.

What is the GST rate on commercial solar EPC?

Commercial rooftop solar EPC contracts attract 12% GST as a composite supply, per CBIC notifications and the applicable works contract provisions. This is higher than the 5% rate for residential composite EPC. The EPC can claim ITC on all inputs (panels at 12%, inverters at 12%, mounting at 18%, cables at 18%), and the commercial customer who is GST-registered can also claim ITC on the 12% charged on the EPC invoice. See our detailed guide on GST on solar systems in India for the full framework.

Can a company claim both Accelerated Depreciation and REC income?

Yes. AD and REC income are independent, a commercial plant owner can claim AD on the asset purchase (under IT Act Section 32) and simultaneously register for and earn RECs on the generation (under CERC regulations). The only restriction is that REC benefits cannot be claimed alongside PM Surya Ghar or other government subsidy schemes. A commercial site that received no government subsidy can claim both AD and RECs.

How much does a 100 kW commercial solar system cost in India?

A 100 kW commercial rooftop solar system in India costs approximately ₹50–₹60 lakh all-in (installed, commissioned, with DISCOM net metering connection) as of mid-2026. The cost varies by state, roof type, inverter brand, and module quality. ALMM-listed modules and Tier-1 inverters are typically required for commercial buyers seeking CERC registration for RECs. See our detailed 100 kW solar price guide for a full breakdown.

How does Accelerated Depreciation work if the system is installed mid-year?

If a solar system is commissioned on or after October 1 (after the halfway point of the financial year April–March), many tax practitioners apply 50% of the normal year's depreciation in the first year, giving 20% AD instead of 40%. This "half-year convention" is widely applied but your CA should confirm your company's specific depreciation policy. To maximise AD, commission before September 30 to ensure the full 40% rate applies.

Is REC income taxable for a commercial solar plant owner?

Yes. REC income is taxable as business income for a commercial entity. It is included in the turnover for income tax purposes and taxed at the applicable corporate tax rate. This does not materially reduce the ROI benefit, even after tax, REC income at ₹99,000/year for a 100 kW plant contributes approximately ₹74,000/year net to the ROI (at 25% tax), adding about 5 months of payback improvement over 25 years.

What happens to Accelerated Depreciation if the solar system is sold?

If a business sells the solar system before it is fully depreciated, the sale proceeds are compared against the written-down book value. If the sale proceeds exceed the book value, the surplus is taxed as a short-term capital gain. If the sale is below book value, a terminal depreciation deduction is available. Businesses planning to sell the property, including the rooftop solar installation, should discuss the tax implications with their CA before the sale.