Navigating Commercial & Industrial Solar Financing in India
Commercial and industrial (C&I) power consumers in India account for over 50% of the nation's total electricity consumption. With state DISCOM grid tariffs continually increasing by 4%–7% annually, adopting rooftop and captive solar power is the single most effective way for factories, warehouses, hotels, and hospitals to slash operating costs.
However, C&I leadership often faces a strategic decision: Should we invest our own capital (CAPEX) or partner with a solar developer under a zero-investment power purchase agreement (OPEX / RESCO)?
30-Second Quick Takeaways
Financial comparison of CAPEX vs OPEX / RESCO solar models
- Two Core Pathways: Commercial and industrial (C&I) enterprises can adopt rooftop solar either via CAPEX (Self-Funded / Bank Loan) where the business owns the asset, or OPEX / RESCO (Zero Upfront Cost) where a renewable developer owns and operates the plant.
- CAPEX Maximum ROI: Under CAPEX, the enterprise reaps 100% of the energy savings from Day 1, gets 40% accelerated tax depreciation, and achieves payback within 2.5 to 3.5 years with internal rates of return (IRR) exceeding 30%.
- OPEX Zero Risk: Under OPEX/RESCO, the developer funds, installs, and maintains the solar system, selling electricity to the factory at a discounted PPA rate of ₹3.80–₹4.50/kWh (saving 50%+ compared to ₹10–₹12 grid power).
- Green Debt Financing: Concessional clean energy credit schemes like SBI Surya Shakti, SIDBI 4E, and IREDA offer 75%–80% debt funding at competitive 8.25%–9.5% interest rates.
Detailed Financial Comparison: CAPEX vs OPEX / RESCO
| Parameter | CAPEX (Direct Purchase / Bank Debt) | OPEX / RESCO (Zero Upfront Cost) |
|---|---|---|
| Upfront Capital Required | 100% Self-funded or 20% equity + 80% loan | ₹0 (Zero Investment) |
| Asset Ownership | Commercial Buyer owns the plant from Day 1 | Solar Developer (IPPs) owns the plant |
| Cost of Solar Electricity | ₹1.80 – ₹2.40 / kWh (levelized over 25 yrs) | ₹3.80 – ₹4.50 / kWh (fixed PPA tariff) |
| 40% Tax Depreciation Benefits | Claimed 100% by Commercial Buyer | Claimed by the Solar Developer |
| Operations & Maintenance (O&M) | Managed by EPC or third-party AMC contract | 100% Managed and guaranteed by Developer |
| Payback Period / IRR | 2.5 to 3.5 Years Payback | 28%–35% Project IRR | Immediate 45%–55% monthly electricity bill cut |
Green Debt Financing: SBI Surya Shakti & IREDA Schemes
For enterprises opting for the CAPEX model, specialized concessional green energy credit lines make financing seamless:
- SBI Surya Shakti Solar Loan: Concessional interest rates (8.25%–9.25%), up to ₹10 Crore financing with 80:20 debt-to-equity ratio and repayment tenure up to 10 years.
- SIDBI 4E (End-to-End Energy Efficiency): Collateral-free green credit for eligible MSMEs up to ₹2 Crore at sub-8% interest.
- Group Captive Open Access: For heavy power consumers requiring 1MW to 20MW without adequate roof space, investing 26% equity in an off-site solar farm provides clean power with zero cross-subsidy surcharge (CSS).
INSTANT CALCULATION
⚡ Calculate Your 2026 Solar Savings & Subsidy
Select your monthly electricity bill to calculate the ideal system capacity, PM Surya Ghar subsidy, and lifetime savings:
Recommended System:
3.0 kW (Rooftop/Hybrid)
PM Surya Ghar Subsidy:
₹78,000 (Central Govt)
Net Out-of-Pocket Cost:
₹1,15,000 – ₹1,35,000
Estimated 25-Yr Savings:
₹9,80,000+
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Frequently Asked Questions (FAQs)
Which model is better for a manufacturing factory: CAPEX or OPEX? +
If your company has capital liquidity or good credit to take an 8.5% bank loan, CAPEX is vastly superior because you capture 100% of free power for 25 years and 40% tax depreciation. If capital is reserved for core business expansion, OPEX/RESCO offers instant 40%–50% bill cuts with zero capital expenditure.
What is the typical tenure of a commercial RESCO PPA in India? +
Commercial solar PPAs generally range between 15 to 25 years. At the conclusion of the PPA term, ownership of the entire solar plant is transferred to the building owner for ₹1.
What collateral is required for SBI Surya Shakti commercial solar loans? +
SBI Surya Shakti solar financing covers up to ₹10 Crore with hypothecation of solar assets as primary security, requiring competitive margins (15%–20%) and standard commercial cash flow backing.
Can MSMEs get collateral-free solar loans in India? +
Yes, through SIDBI's 4E (End-to-End Energy Efficiency) scheme and CGTMSE guarantee-backed clean energy loan windows, eligible MSMEs can secure up to ₹2 Crore without third-party collateral.