Solar EPC Contract Clauses: India Industrial Buyer Guide 2026

Key Takeaways

• A solar EPC contract is the most critical document in your solar project — it determines legal protections, performance accountability, and financial outcomes for 25+ years
• The most important clauses: performance guarantee (kWh/year or Performance Ratio), liquidated damages for underperformance and delays, Defect Liability Period (DLP), ALMM compliance, and accelerated depreciation documentation
• Performance Ratio guarantee should be 78-82% for Year 1 (with defined degradation allowance for subsequent years)
• Liquidated damages (LD) clauses should cover both commissioning delays (₹X per day) and generation shortfalls (proportional LD per kWh below guarantee)
• Payment milestones must be tied to physical milestones, not calendar dates — 30% advance, milestone-based balance, 5-10% retention
• From June 2026, contracts must explicitly state ALMM List-II compliance (Indian-manufactured solar cells) to ensure net-metering and accelerated depreciation eligibility

Signing a solar EPC (Engineering, Procurement & Construction) contract is one of the most significant long-term procurement decisions an industrial facility can make — the plant will operate under the terms of this contract for 25+ years. Yet many industrial buyers focus primarily on the upfront price per watt and overlook the contract clauses that determine actual long-term value, legal protection, and recourse in case of performance shortfalls.

This guide covers the 10 most critical EPC contract clauses for Indian industrial solar buyers in 2026, written from the perspective of an experienced industrial solar EPC company that has structured and executed hundreds of contracts across India.

1. Scope of Work (SOW) — Be Exhaustive, Not Generic

The single most common source of disputes in solar EPC contracts is an inadequately defined Scope of Work. A strong SOW must specify:

What Must Be Included in the SOW

• Module specifications: brand, model, watt-peak rating, efficiency, temperature coefficient, ALMM certification, INSOLCHECK or IEC certification
• Inverter specifications: brand, model, rated capacity, efficiency, IP rating, communication protocol (Modbus, SunSpec)
• Structure specifications: mounting material (GI/MS or aluminium), galvanizing thickness (minimum 85 microns for IS-2062 HDG), design wind speed (per IS-875 Part 3, state-specific)
• Electrical works: AC and DC cable specifications (IS:694 conductor type, armoring), junction box ratings, switchgear (MCB, MCCB, ACB specifications), metering type
• Civil works: roof penetrations, mounting points, cable conduit routing, earthing and lightning protection (per IS:3043)
• DISCOM approval coordination: net metering application, HT connection modification, export meter installation
• Monitoring system: data logger, communication hardware, software platform (web + mobile), minimum 5-year software license
• Safety compliance: IS codes compliance list, CEA safety certificates, CEIG approvals (where applicable)
• Documentation deliverables: as-built drawings, SLD (Single Line Diagram), test certificates, O&M manuals, warranty cards

The key risk: contracts using generic language like "supply and install solar panels as per site survey" leave scope gaps that become contractor leverage for variation orders. The SOW must be specific enough that there is no ambiguity about what is included.

2. ALMM Compliance Clause (Critical from June 2026)

From June 1, 2026, MNRE's ALMM List-II mandate requires that solar modules used in net-metering, open access, and government scheme projects must use cells manufactured by Indian ALMM-approved manufacturers. Your EPC contract must explicitly address this.

What to Include in the ALMM Clause

"The Contractor shall supply only solar PV modules that are certified under MNRE's Approved List of 
Models and Manufacturers (ALMM) List-II, using solar cells manufactured by ALMM-approved domestic 
manufacturers. The Contractor shall provide the ALMM certificate number for each module supply at 
the time of commissioning. Non-compliant module supply shall be grounds for rejection and replacement 
at the Contractor's cost."

Without this clause, a contractor may supply modules using imported cells (non-ALMM-compliant), which:

• Prevents net metering approval from the DISCOM
• Disqualifies the plant from accelerated depreciation benefit (40% in Year 1)
• Creates liability for PM Kusum or other government scheme participation

See our complete ALMM mandate guide for the full policy background.

3. Performance Guarantee — The Core of Your Contract

The performance guarantee is the single most financially impactful clause in your EPC contract. It defines what the solar plant will actually deliver, and provides recourse when it underdelivers.

Performance Ratio (PR) Guarantee

The most important performance metric is the Performance Ratio (PR) — the ratio of actual energy output to theoretical maximum output based on irradiation and installed capacity:

• Year 1 PR guarantee: 78-82% (industry standard for rooftop industrial solar in India)
• Degradation allowance: typically 0.5% per year (meaning Year 5 PR can be 78-82% minus 2.5%)
• Measurement basis: annual measurement period (not quarterly, to account for seasonal variation)
• Exclusions: legitimate exclusions include grid downtime beyond X hours/month, force majeure events, and manufacturer defects during warranty claim processing

Annual Energy Generation Guarantee

Some contracts specify energy generation guarantees in kWh/year rather than PR:

• For a 1 MW rooftop system in a 1,500 kWh/kWp irradiation zone with 80% PR: approximately 1,200 MWh/year guaranteed generation
• The contract should state: "Contractor guarantees minimum energy generation of X MWh/year from the system for a period of Y years, subject to grid availability and irradiation within Z% of P90 baseline"

P90 Irradiation Baseline

A well-structured performance guarantee references a P90 irradiation baseline — the irradiation level exceeded 90% of the time based on historical data (Global Solar Atlas, Meteonorm, or site-specific measurement). This prevents disputes when low-irradiation years reduce generation below the nominal guarantee.

4. Liquidated Damages (LD) — Two Types Matter

Liquidated damages (LD) clauses provide pre-agreed financial remedies for contractor failures without requiring proof of actual loss. Your contract needs LD clauses for two distinct scenarios:

Type 1: Commissioning Delay LD

If the contractor fails to commission by the agreed date:

• Standard rate: ₹X per day (typically 0.1-0.2% of contract value per week of delay, capped at 10-15% of total contract value)
• Milestone-triggered: LD starts accruing after a defined grace period (typically 15-30 days beyond target commissioning date)
• Force majeure carve-out: LD does not accrue for delays caused by force majeure events, buyer-caused delays (late structural drawings, delayed DISCOM approvals), or imported equipment customs delays (if contracted delivery window is exceeded)

Type 2: Performance Shortfall LD

If the plant generates less than the guaranteed kWh/year:

• Standard mechanism: for every kWh below the annual guarantee, the contractor pays the buyer at the applicable grid tariff rate (or higher, as negotiated)
• Example: If guarantee is 1,200 MWh/year and actual is 1,100 MWh/year, LD = 100 MWh × applicable tariff (e.g., ₹8.50/kWh) = ₹8.5 lakh for that year
• Annual measurement: typically measured over 12 months to account for seasonal variation
• Cure period: contractor should be given opportunity to remedy performance shortfall before LD kicks in

Critical: ensure LD clauses are bilateral where appropriate — if the buyer causes delays (late structural approvals, delayed grid connectivity), the contractor should have equivalent protection.

5. Defect Liability Period (DLP) — 12 Months Minimum, 24 Preferred

The Defect Liability Period (DLP) covers the period after commissioning during which the contractor is responsible for repairing any defects in workmanship or materials at no cost to the buyer.

DLP Best Practices

• Minimum DLP: 12 months from commissioning date (industry minimum)
• Preferred DLP: 24 months for roof penetration, structural works, and civil items that may reveal defects only after monsoon season
• Scope of DLP: workmanship defects, material defects, wrong installation, structural failures — but NOT module or inverter manufacturing defects (those are covered by equipment warranties)
• DLP retention: retain 5-10% of contract value until DLP expires as security against defect rectification default
• Response time SLAs: contractor must respond to defect notification within 24-48 hours; repair within 7-14 days for non-critical defects, 24 hours for safety-critical issues

Distinction from Equipment Warranty

DLP ≠ Equipment Warranty. The contractor's DLP covers workmanship; manufacturer warranties cover equipment defects:

• Module warranty: 25-30 years linear power output (at 80-83% of rated power at end of warranty)
• Inverter warranty: 10-12 years (extended warranty available for 15 years with annual fee)
• Structure/mounting: 10-15 years (manufacturer warranty on galvanizing quality)

6. Payment Milestones — Tie to Physical Progress

Payment structure is the #1 leverage point for ensuring contractor performance. Milestone-tied payment ensures the contractor cannot receive payment before demonstrating physical progress:

Recommended Payment Structure for Indian Industrial Solar EPC

Critical: The 30% advance payment should be backed by an Advance Bank Guarantee (ABG) from a scheduled bank, valid for 6 months beyond the contracted commissioning date. This protects against contractor insolvency after advance payment.

7. Equipment Brand and Model Lock-In

A common contractor practice is to specify a "make or equivalent" clause that allows substitution of lower-quality equipment after contract signing. Prevent this with explicit brand and model lock-in:

• Modules: specify exact ALMM-listed brand and model (e.g., Waaree 555W Bifacial TOPCon WS-555BD or equivalent with buyer's prior written approval)
• Inverters: specify exact model (Sungrow SG125CX or Huawei SUN2000-125KTL) — not just "Tier-1 inverter"
• Any substitution requires buyer's written approval at least 30 days before delivery
• Substitution clause: "Any substitute equipment must be of equal or superior specification and ALMM-certified; Contractor bears all cost and schedule risk from substitution"

See our Waaree vs Trina solar panel comparison and string vs central inverter guide for equipment evaluation criteria.

8. Accelerated Depreciation Documentation Clause

Industrial buyers claiming the 40% accelerated depreciation (AD) benefit in Year 1 under the Income Tax Act need specific documentation from the contractor. Your EPC contract must specify this:

Required Documentation for AD Claim (Section 32, Income Tax Act)

The Contractor must provide:

1. Commissioning certificate: signed by contractor and third-party inspector, with exact commissioning date and system capacity
2. Asset-wise cost breakup: module cost, inverter cost, structural cost, electrical cost, civil cost — in the format required by the buyer's auditor for fixed asset registration
3. Equipment test certificates: IEC/BIS test certificates for modules and inverters
4. CEA compliance certificate: compliance with Central Electricity Authority (Technical Standards for Construction of Electrical Plants and Electric Lines) Regulations
5. ALMM certificate copies: for each module batch, confirming ALMM List-II compliance for cell and module

Failure to provide AD documentation can result in the buyer losing ₹41-47 lakh of tax savings on a 1 MW project. See our solar accelerated depreciation guide for the full calculation.

9. O&M Scope and Transition Clause

Most EPC contracts include 1-2 years of free O&M. Your contract should clearly define the O&M scope and the transition process to either buyer's in-house O&M or a separate O&M provider:

During EPC-Included O&M Period (Typically Year 1-2)

• Preventive maintenance schedule: quarterly cleaning + biannual thermal imaging + annual system audit
• Response time SLAs: 24-hour response for production losses above X%, 4-hour response for total plant outage
• Monitoring access: buyer should have independent real-time monitoring access (not just contractor access)
• Performance reporting: monthly generation reports vs guarantee

O&M Transition Clause

At end of included O&M period, the contractor must:

• Provide complete as-built documentation and maintenance records
• Transfer monitoring platform access to buyer
• Conduct a joint condition inspection with snagging list
• Facilitate knowledge transfer to buyer's facility team or new O&M provider

For ongoing operations, see our solar O&M guide for India and solar monitoring system guide.

10. Insurance and Safety Compliance Clauses

Construction Phase Insurance

The EPC contract should specify that the contractor maintains:

• Contractor's All Risk (CAR) insurance: covering the full project value during construction (buyer named as co-insured)
• Workmen's Compensation (WC) insurance: mandatory under the Workmen's Compensation Act 1923
• 3rd Party Liability: minimum ₹10 Cr per occurrence
• Insurance certificates must be submitted before mobilization

Safety Compliance Requirements

• HSE (Health Safety Environment) plan submitted 15 days before mobilization
• IS codes compliance: IS:875 Part 3 (wind loads), IS:3043 (earthing), IS:694 (cables), IS:61730 (PV module safety)
• CEA regulations compliance: Technical Standards for Construction of Electrical Plants (2010)
• All workers must have valid BOCW (Building and Other Construction Workers) registration

How to Evaluate Your EPC Contract

Use this checklist before signing:

A reputable solar EPC company in India will have standard contract templates incorporating all these clauses. If a contractor resists including performance guarantees, LD clauses, or ALMM compliance requirements in the contract, treat this as a major red flag.

FAQ: Solar EPC Contract Clauses for Indian Industrial Buyers

Q: What is the most important clause in a solar EPC contract? The most important clause is the performance guarantee — specifically, the PR (Performance Ratio) guarantee specifying the minimum annual energy output and the liquidated damages for shortfalls. Without a strong performance guarantee with financial consequences, there is no enforceable accountability for underperformance.

Q: What is a reasonable Defect Liability Period for industrial solar? The minimum acceptable DLP is 12 months from commissioning. For industrial projects with significant civil works (ground-mount, structural rooftop modifications), 24 months is preferred as monsoon testing reveals structural defects not visible at commissioning.

Q: How do I protect against advance payment misuse? Require an Advance Bank Guarantee (ABG) equal to 100% of the advance payment, issued by a scheduled bank (not an insurance company bond), valid through commissioning plus 6 months. The ABG can be invoked if the contractor fails to commission within the contracted timeline.

Q: What happens if my contractor supplies non-ALMM modules? Non-ALMM modules (those using imported solar cells, post June 2026) will be rejected by DISCOM for net-metering approval, disqualify the project from accelerated depreciation, and may affect warranty claims. Your contract should specify ALMM compliance as a condition of payment and provide for replacement at the contractor's cost.

Q: Should I have a lawyer review the EPC contract? Yes, particularly for projects above ₹1 Cr (500 kW+). An energy transactions lawyer familiar with CEA regulations, DISCOM interconnection agreements, and the Electricity Act 2003 can identify gaps in the standard EPC template. Sun Wave Technologies provides contract review advisory as part of our EPC services.

Q: What documentation do I need from my EPC contractor for tax purposes? For accelerated depreciation (Section 32), you need: commissioning certificate with exact date and capacity, asset-wise cost breakup for fixed asset registration, equipment test certificates, CEA compliance certificate, and ALMM List-II compliance documentation. Ensure these are specified as contract deliverables before signing.

Sources

• HLK Infra: How to Read and Evaluate an EPC Contract in India
• Energetica India: MNRE Seeks Monthly Solar Cell and Module Price Data
• Central Electricity Authority (Technical Standards for Construction of Electrical Plants and Electric Lines) Regulations 2010
• IS:875 Part 3 — Wind Loads for Buildings and Structures
• IS:3043 — Code of Practice for Earthing