What is Accelerated Depreciation (AD) under Section 32 of the Income Tax Act for solar plants?

Under Section 32 of the Indian Income Tax Act 1961, commercial and industrial enterprises investing in renewable energy devices, including rooftop solar PV plants, are eligible for 40% Accelerated Depreciation on the Written Down Value (WDV) of the asset. This allows profitable businesses to write off a major portion of their solar capital expenditure against taxable business income, creating a substantial cash tax shield.

What is the 180-day rule for claiming solar depreciation in Year 1?

If a rooftop solar plant is commissioned and put to use for 180 days or more in the financial year (on or before October 3rd), the business can claim the full 40% depreciation in Year 1. If commissioned after October 3rd (less than 180 days), 50% of the eligible rate (20%) is claimed in Year 1, and the remaining 20% is claimed in Year 2.

Are manufacturing companies eligible for Additional Depreciation on rooftop solar?

Yes. Under Section 32(1)(iia), businesses engaged in manufacturing or power generation can claim an Additional Depreciation of up to 20% in the first year of commissioning, in addition to the standard 40% accelerated depreciation, provided they operate under the standard corporate tax regime.

What is the typical payback period for a commercial rooftop solar plant in India?

For Indian MSMEs and commercial businesses, commercial electricity tariffs are high (₹9 to ₹14 per unit) and on-site daytime consumption is 85% to 95%. When combined with the 40% Accelerated Depreciation tax shield, the net capital investment is recovered within 1.8 to 2.8 years. For the remaining 22+ years of the panel warranty, solar electricity is virtually free.

What is the difference between Capex and Opex (RESCO) solar models for commercial entities?

In the Capex model, the business self-funds or takes a bank loan (e.g. SIDBI 4E or SBI Surya Shakti) to own the solar plant, claims 100% of the Section 32 tax depreciation benefits, and enjoys maximum lifetime savings. In the Opex/RESCO model, a third-party developer installs and owns the plant on the business's rooftop at zero upfront cost, selling the generated solar electricity to the business at a 20% to 40% discount to DISCOM grid tariffs.

Income Tax Act Section 32 Commercial Solar Suite

Commercial Solar Accelerated Depreciation Calculator (Section 32 Tax Shield, Capex & 25-Year Commercial ROI)

Model 40% Accelerated Depreciation tax write-offs, corporate tax cash savings, high-tariff commercial electricity offsets, and payback periods (1.8–2.8 years) for 10 kW to 1 MW rooftop solar plants.

Income Tax Act 1961 Section 32 Compliant • SIDBI 4E & SBI Surya Shakti Finance Model • 100% Client-Side Privacy

1. Commercial Plant Capacity

Medium MSME

Rooftop Solar Plant Capacity 100 kWp

10 kW (Small Clinic) ~8,000 sq.ft terrace 1,000 kW (1 MW)

Turnkey Capex Rate (₹ / kWp) ₹42,000 / kW

Total Gross Capex: ₹42,00,000

2. Corporate Tax & Section 32 Rules

Business Entity & Corporate Tax Rate

Commissioning Timeline (180-Day Rule)

≥ 180 Days Put to use by Oct 3 (40% Year 1)

< 180 Days After Oct 3 (20% Y1 + 20% Y2)

Manufacturing Entity: +20% Additional Depreciation Section 32(1)(iia) grants an extra 20% depreciation in Year 1 for manufacturing plants (Standard regime).

3. Commercial Power Tariff & Usage

Commercial / Industrial Power Tariff ₹11.50 / kWh

Includes HT/LT energy charges, wheeling charges & fuel surcharge.

On-Site Self Consumption Ratio 92%

Commercial facilities consume 85–95% of solar power directly during daytime operations.

Commercial Solar Loan Option 70% Debt : 30% Equity

100% Self Funded 70% SIDBI/SBI Loan

Section 32 Tax Shield + Energy Offset

Commercial Solar Financial Return

2.1 Years Payback

Year 1 Tax Cash Shield ₹4,22,856 40% AD write-off

Annual Power Bill Saved ₹14,94,840 1,32,000 units/year

Net Effective Capex ₹31,42,860 After 3-Yr tax shield

25-Year Net Project Profit:

₹4,12,50,000

Project Internal Rate of Return (IRR):

34.8% p.a. (Tax Free)

5-Year Income Tax Depreciation & Cash Shield Schedule

Written Down Value (WDV) write-offs under Section 32

Section 32

Financial Year	Opening WDV	Depreciation Claimed	Closing WDV	Direct Tax Saved (₹)

Capex (Own Asset) vs. Opex (RESCO PPA) Comparison

Which commercial ownership model delivers higher enterprise value?

Option A: Capex Ownership Recommended

Asset Ownership: Plant appears as an asset on your balance sheet.
Tax Benefits: 100% of 40% Accelerated Depreciation tax shield is retained by you.
Power Cost: ₹0/unit after payback period (2.1 years).
25-Year Savings: Maximum wealth retention (₹4.1+ Cr).

Option B: Opex / RESCO PPA Zero Upfront

Zero Capital: Third-party developer finances and owns the panels.
No Tax Shield: The developer claims the 40% AD tax shield, not you.
Tariff Discount: You purchase solar power at ~₹6.50 to ₹7.50/unit for 25 years.
25-Year Savings: Moderate savings (~40% of Capex value).

Model DISCOM Net Metering Banking →

Corporate Tax Planning & Clean Energy

How Section 32 40% Accelerated Depreciation Creates a Massive Tax Shield for Indian Businesses

For profitable Indian MSMEs, manufacturers, hospitals, commercial complexes, and private limited companies, rooftop solar power is one of the highest-yielding corporate capital investments available under the Indian tax framework.

While typical plant and machinery assets in India are depreciated at standard rates of 15% per annum under the Written Down Value (WDV) method, Renewable Energy Devices (including Solar Photovoltaic systems) are categorized under a specialized depreciation block entitled to an Accelerated Depreciation (AD) rate of 40% under Rule 5 of the Income Tax Rules 1962 and Section 32 of the Income Tax Act 1961.

Section 32 Base

40% Accelerated Depreciation

Allows businesses to write off 40% of the solar asset value in the first year against gross commercial taxable profits. At a 25.17% corporate tax rate, this yields an instant cash tax savings equal to ~10% of the total capex in Year 1 alone.

Section 32(1)(iia)

+20% Additional Depreciation

Available to manufacturing companies and businesses engaged in the generation or transmission of power. Allows an additional 20% one-time depreciation in the year of installation, bringing total Year 1 write-offs to 60%!

Commercial Power Offset

High-Tariff Elimination

Commercial grid tariffs in India range from ₹9 to ₹16/unit. Because businesses operate during daylight hours, up to 95% of solar power is consumed directly, replacing expensive grid imports with ₹0/unit generation.

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Real-World Case Study: 100 kW Commercial Rooftop Solar on an Indian Factory

Financial Parameter	Without Solar (Grid Only)	With 100 kW Solar + 40% AD
Turnkey Capital Outlay	₹0	₹42,00,000 (@ ₹42k/kW)
Year 1 40% AD Tax Shield (25.17% Corp Tax)	₹0	-₹4,22,856
Year 2 40% AD Tax Shield	₹0	-₹2,53,714
Net Effective Capital Outlay	₹0	₹32,70,000 (22% recovered from tax alone)
Annual Power Bill Savings (1,32,000 units @ ₹11.50)	₹0	₹15,18,000 / year
Simple Payback Period	Perpetual monthly bills	2.1 Years (Fully recovered by Month 26)

Commercial Solar Loan Schemes for Indian MSMEs

SIDBI 4E Scheme

End-to-End Energy Efficiency

Concessional financing at 7.5%–8.5% interest rate for rooftop solar investments by eligible MSMEs, with up to 90% project funding.

SBI Surya Shakti Solar

Dedicated Commercial Solar Line

State Bank of India financing up to ₹10 Crore for commercial and industrial rooftop projects, with loan tenures up to 10 years.

Tata Capital / IREDA

Green Energy Infrastructure Loans

Non-banking financial corporation (NBFC) credit lines tailored for C&I rooftop plants with structured repayment matching monthly DISCOM power savings.

Frequently Asked Questions (Commercial Solar & Accelerated Depreciation)

Can an individual proprietorship or LLP claim 40% Accelerated Depreciation on solar?

Yes. Any entity carrying on a business or profession in India (Proprietorships, Partnership firms, LLPs, and Companies) can claim 40% Accelerated Depreciation under Section 32, provided the solar plant is owned by the business and used for business operations.

Can a company opt for Section 115BAA (22% corporate tax) and still claim 40% Accelerated Depreciation?

Yes. While Section 115BAA disallows certain special tax incentives (like Additional Depreciation under Section 32(1)(iia) and Section 35AD deductions), the standard 40% depreciation block for Renewable Energy Devices under Section 32 is fully allowed under the Section 115BAA corporate tax regime.

What is the GST rate on commercial rooftop solar installations?

Under GST Council rulings, commercial solar projects are billed under a composite 70:30 ratio (70% considered goods at 12% GST and 30% considered service at 18% GST), resulting in an effective composite GST rate of 13.8%. GST registered businesses can claim Input Tax Credit (ITC) on the GST paid, reducing net out-of-pocket capex.

What happens to unabsorbed solar depreciation if the business incurs a loss?

Under Section 32(2) of the Income Tax Act, any unabsorbed depreciation that cannot be set off against taxable business profits in the current financial year can be carried forward indefinitely and set off against business income in subsequent assessment years without any 8-year limitation period.

How much terrace area is needed for a 100 kW commercial solar plant?

Using modern high-efficiency TOPCon or Mono-PERC solar panels (550Wp to 600Wp per module), a 100 kW solar system requires approximately 7,500 to 8,500 square feet (700 to 800 square meters) of shadow-free rooftop or industrial shed area.

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