Most solar engineering disputes begin not with a technical failure but with a contract that the parties never properly understood.
Liquidated damages, professional indemnity insurance, and performance bonds are the three financial mechanisms that sit between “the plant underperformed” and “someone pays.” For Indian utility-scale developers and US C&I developers alike, getting these terms right before signing is one of the most valuable legal steps either party can take.
Quick answer. In solar engineering contracts, liquidated damages (LD) are pre-agreed financial penalties for underperformance or delay, set per contract. For schedule delay, the SECI general conditions for a 300 MW EPC tender (2024) use 0.5% of contract price per week with a 5% maximum, and performance LD is set separately. Professional indemnity (PI) insurance covers design errors and omissions, the policy limits that matter for solar engineering are set by the contract and, on financed projects, by the lender. Performance bonds (bank guarantees, sized in the contract) protect the owner if the EPC defaults. SECI’s 2024 EPC tender asks for performance security of 5% of contract value for the supply and services stage. All three must be specified in the contract before work starts, not negotiated after a problem occurs.
TL;DR
- Liquidated damages must be a genuine pre-estimate of loss, not a penalty, schedule LD rates and caps are set per contract. SECI's general conditions for a 2024 EPC tender use 0.5% of contract price per week with a 5% maximum (clause 20).
- Professional indemnity (PI) insurance covers design errors and omissions, not physical damage or delay. Cover limits and the period the policy must stay active after commissioning are set by the contract and the lender.
- Performance bonds (bank guarantees in India, surety bonds in the USA) are typically 5-10% of contract value and protect the owner against contractor default, not routine underperformance.
- Force majeure clauses should be narrowly defined, grid curtailment and equipment supply delays are project risks, not FM events, and should not shield the EPC from schedule LD.
- Engineering-only contracts should cap LD at the engineering fee, not the full EPC value, since the designer cannot control 25-year variables like degradation or soiling.
- Lenders set their own minimum LD, PI insurance, and bond standards. Get them in writing and meet them before financial close, or the contract may be flagged during lender review.
This guide is written for US C&I developers who subcontract engineering and need MSA-ready contract language, and for Indian utility-scale developers working under IREDA financing, where lenders set minimum LD and insurance standards. Both markets are covered with the relevant currency conventions and regulatory context.
Liquidated Damages: The Most Misunderstood Solar Contract Term
Liquidated damages are not a penalty. That distinction is critical in both Indian and US contract law.
An LD clause specifies a pre-agreed, reasonable estimate of the damages the owner will suffer if the contractor fails to meet a specific obligation. A court will enforce an LD clause if the agreed amount is a genuine pre-estimate of loss, and will strike down a clause if it is a disguised penalty.
Definition. Liquidated damages (LD) are a contractually specified sum that one party agrees to pay the other in the event of a defined breach, most commonly schedule delay or performance shortfall. Unlike unliquidated (actual) damages, LD clauses establish the compensation amount in advance, removing the need to prove actual loss in court.
LD for Schedule Delay
The schedule LD clause compensates the owner for revenue lost while the plant is not generating. The standard formula:
Daily LD rate = (Daily expected revenue × Debt service factor) / Contract value
Delay LD rates and caps are set per contract, so there is no single standard. The first row is a published SECI example, taken from clause 20 of the general conditions of tender SECI/C&P/OP/11/013/2023-24 (dated 06/03/2024, 300 MW Ramagiri, Andhra Pradesh). The other rows have no standard figure, so take them from your own contract:
| Market | Typical Delay LD Rate | Cap | Trigger |
|---|---|---|---|
| India (SECI EPC tender, 2024, GCC clause 20) | 0.5% of contract price per week | 5% of contract price | Delay beyond the contracted completion time |
| India (Private C&I) | Set by the contract | Set by the contract | Agreed completion date |
| USA (C&I, private) | Set by the contract | Set by the contract | Agreed substantial completion date |
| USA (Utility, PPA-linked) | Based on PPA delivery obligations | Set by the contract | First day of PPA delivery term |
Field tip. In SECI auction contracts, the EPC's schedule LD exposure flows directly from the developer's SECI LD exposure. If the developer's own contract with SECI charges it for late commissioning, the EPC's delay LD should be sized against that exposure plus the developer's lost tariff revenue for the delay period. Read the developer's contract for the actual rate.
LD for Performance Shortfall
Performance LD compensates the owner for sustained generation below the guaranteed level. The trigger is typically a performance test at commissioning (PR test per IEC 61724-1, with the test procedure written into the contract) and annual energy audit during the warranty period. The technical schedules that carry the test, the approvals and the handover list belong in the same contract.
Standard structures for performance LD in solar engineering contracts:
- PR-based LD: If tested PR is below the guaranteed PR (set in the contract; for example, one SECI 2024 tender contracted 81.50% measured at the 220 kV side of the pooling substation, a value that belongs to that site), LD is applied as a multiple of the shortfall. Formula: LD = (Guaranteed PR − Achieved PR) × Installed kWp × Tariff × Hours × LD multiplier.
- Annual energy-based LD: If annual generation is below the guaranteed figure (P50 yield), LD is calculated as (Guaranteed kWh − Actual kWh) × Tariff rate × LD multiplier.
5%
Delay LD cap in one SECI EPC tender (example)
SECI GCC clause 20, tender dated 06/03/2024
12 months
Defect liability period in one SECI EPC tender (example)
SECI GCC, tender dated 06/03/2024 (latent defect liability is separate)
Per contract
PI insurance limits
Set by the contract and the lender
5%
Performance security in one SECI EPC tender (example)
SECI SCC (GCC clause 24), tender dated 06/03/2024
Professional Indemnity Insurance: The Engineering Coverage Most EPCs Lack
Professional indemnity (PI) insurance, called errors and omissions (E&O) insurance in the USA, covers the financial consequences of a design error, a miscalculation, or an incorrect specification that causes loss to the client. It is distinct from general liability insurance (which covers bodily injury and property damage during construction) and is specifically triggered by a professional’s failure to exercise reasonable skill and care.
When PI Insurance Applies in Solar Engineering
PI insurance is triggered when:
- A design error causes underperformance (e.g., incorrect string sizing causes inverter clipping that the designer could have avoided)
- A structural calculation error causes a mounting system failure after commissioning
- An incorrect CEIG or DISCOM drawing causes a regulatory rejection that delays commissioning
- An energy yield report is found to have a systematic methodology error that caused the plant to generate 8% less than the guaranteed figure
PI insurance does not cover:
- Deliberate acts or fraud
- Claims known before the policy inception date
- Contractual obligations beyond reasonable professional care (i.e., LD for delay is not a PI claim)
- Physical damage to the plant (that is contractor all-risk / property insurance)
PI Insurance Minimums by Market
| Market | Minimum PI Cover (per claim) | Minimum PI Cover (aggregate) | Who Must Hold It |
|---|---|---|---|
| India (lender-financed projects) | Set by the lender | Set by the lender | Design consultant, IE firm |
| India (private C&I) | Set by the contract and the client’s insurer | Set by the contract and the client’s insurer | Design consultant |
| USA (C&I) | Set by the MSA and the client’s insurer | Set by the MSA and the client’s insurer | Engineering firm |
| USA (utility, DFI-financed) | Set by the lender | Set by the lender | Owner’s engineer, design engineer |
Watch out. PI insurance is a "claims-made" policy, meaning the claim must be filed while the policy is active, not necessarily when the error occurred. If your engineering consultant lets the PI policy lapse after project commissioning, a design error discovered later may not be recoverable. Contracts should require that PI insurance remain in force for a defined period after project commissioning and that the consultant provide annual proof of renewal.
The Solar Engineering Contract Risk Framework
This is Heaven Designs’ proprietary Solar Engineering Contract Risk Framework, a structured approach to allocating LD, insurance, and bond requirements across the engineering contract lifecycle.
Scope Definition Gate
Before any LD clause is drafted, the engineering scope must be precisely defined, what deliverables, to what standard, and by what date. A vague scope makes LD clauses unenforceable because the trigger event (failure to deliver "adequate drawings") is contested. Every deliverable in the SOW should have a defined completion criteria, see [bid-stage vs IFC-stage engineering deliverables](/blog/bid-stage-vs-ifc-stage-engineering/) for how that standard changes by project phase.
Risk Allocation Matrix
Map each project risk to the party best placed to control it. Design errors → PI insurance on the engineering consultant. Construction delay → schedule LD on the EPC. Equipment failure in warranty → manufacturer's warranty pass-through. Force majeure → shared exclusion. This mapping drives the contract structure, not the other way around.
Insurance Certificate Collection
Collect insurance certificates before work starts, not after. Require: PI/E&O certificate (with named insured, per-claim and aggregate limits, and effective dates), contractor all-risk (CAR) certificate, and workmen's compensation certificate. Require annual renewal certificates as a contract obligation throughout the design and warranty period.
Performance Bond Execution
Require the performance bond (bank guarantee, BG) before the first milestone payment is released. The BG issuing bank should be acceptable to the lender (for financed projects, lenders specify a panel of acceptable banks). Confirm the BG validity extends to at least 30 days beyond the defect liability period end date.
LD Trigger Documentation
Define each LD trigger precisely: the schedule delay LD trigger must reference a specific milestone date (COD, not a general "completion"), and the performance LD trigger must reference a specific test standard (IEC 61724-1, duration: 30 days of continuous monitoring). Ambiguous triggers are the primary reason LD clauses are disputed rather than paid.
Lender Alignment Check
Before finalizing the EPC or engineering contract, cross-check every LD clause, insurance minimum, and bond term against the lender's LDED requirements. Lenders set their own minimum standards (see the section below). An EPC contract that falls short of the lender's requirements can be flagged in the lender's review and may need renegotiation before financial close.
Performance Bonds: Structure, Bank Guarantees, and Alternatives
A performance bond in solar engineering contracts is a financial guarantee that the contractor will complete the work as specified. If the contractor defaults, the bond is called and the owner receives funds to engage a replacement contractor.
Types of Performance Security in Indian Solar Projects
| Bond Type | Trigger | Issuer | Amount |
|---|---|---|---|
| Bank Guarantee (BG) for performance | Contractor default / failure to achieve COD | Scheduled bank acceptable to lender | Set by the contract (5% in one SECI EPC tender, GCC clause 24) |
| Retention Money | Withheld at payment milestones where the contract provides for it | Deducted from contractor invoice | Set by the contract, usually released at DLP end |
| Advance Payment Guarantee | Where the contract pays a mobilisation advance | Scheduled bank | Usually equal to the advance amount |
| Warranty Bond | Performance shortfall during DLP | Insurance company or bank | Set by the contract |
In the USA, performance bonds are typically issued by a surety company rather than a bank. The structure is the same (the surety pays if the contractor defaults) but the mechanism is different, and the bond amount and term are set by the EPC contract.
Force Majeure: What It Covers and What It Does Not
Force majeure (FM) clauses suspend the contractor’s obligations during events outside both parties’ control. In solar engineering contracts, the definition of FM is frequently disputed. Standard Indian solar EPC contracts (based on FIDIC Yellow Book adapted for India) define FM as:
- Natural disasters: earthquake, flood, cyclone, lightning
- Government actions: war, sanctions, export restrictions
- Pandemic (post-2020 addition)
Force majeure does not typically cover:
- DISCOM or SECI grid availability issues (grid curtailment is a known project risk, not FM)
- Module or inverter supply delays (supply chain issues are a contractor risk)
- Labor strikes (except general strikes declared by the state government)
Watch out. Many Indian EPC contracts drafted by developers include grid unavailability or government transmission planning delays in the FM definition, meaning the developer bears the revenue risk of grid curtailment without a contractual remedy against the EPC. This is inappropriate. Grid risk is a regulatory risk that sits with the developer and the regulator, not the EPC. Ensure the FM clause is narrowly defined and that grid issues are addressed separately in the PPA's curtailment compensation provisions.
Comparison: Engineering-Only vs EPC Contract LD Structures
| Contract Type | Engineering-Only (Design Firm) | Full EPC Contract |
|---|---|---|
| Schedule LD trigger | Late delivery of specified drawings | Late COD |
| Performance LD trigger | Yield shortfall in bankable PVsyst report | Annual generation below guaranteed figure |
| PI insurance required | Yes, standard per-claim/aggregate | PI required for the design sub-contractor |
| Performance bond | Rarely, retention money more common | Yes, 5-10% BG standard |
| LD cap | Set by the contract, often tied to the engineering fee | Set by the contract (the SECI example above caps delay LD at 5%) |
| Maximum contractor liability | Engineering contract value | EPC contract value × LD cap % |
The distinction between engineering-only and EPC LD structures matters because developers sometimes inadvertently apply EPC contract terms to engineering-only engagements, or vice versa. An engineering-only contract where the consultant is responsible only for design deliverables should not carry an unbounded performance LD linked to the plant’s 25-year yield.
The engineer cannot control module degradation, grid availability, or soiling frequency, and an LD clause that attempts to make the engineer responsible for these variables will either be unenforceable or will price the engineering service at a significant risk premium.
WELL-STRUCTURED CONTRACT
- Each risk allocated to the party controlling it
- LD triggers precisely defined with test standards and dates
- PI insurance covers design errors for 5+ years post-commissioning
- Performance bond covers contractor default, not normal performance shortfall
- FM clause is narrow and specifically excludes grid and supply chain risks
POORLY STRUCTURED CONTRACT
- Engineering firm exposed to 25-year yield shortfall LD
- No PI insurance requirement, design error unrecoverable
- FM clause covers grid curtailment, EPC faces no schedule LD risk
- Performance bond absent, no recourse if EPC defaults
- LD cap is a percentage of engineering cost, not EPC cost
See a bankable engineering deliverable with PI insurance documentation
Download a sample Heaven Designs engineering package, including the MSA insurance certificate, SOW scope definition, and a redacted PVsyst report from a recently closed project.
Get the sample pack →Insurance Types Required in Solar Engineering Contracts
Beyond PI insurance, a complete solar project contract requires multiple insurance products. Developers who do not specify all required insurance types in the contract create gaps that an unscrupulous contractor can exploit.
| Insurance Type | What It Covers | Who Holds It | Minimum Limit |
|---|---|---|---|
| Contractor All Risk (CAR) | Physical damage to work in progress during construction | EPC contractor | Full EPC contract value |
| Advanced Loss of Profits (ALOP) | Revenue loss during construction delay due to insured event | Developer | Set by the lender and the insurer |
| Professional Indemnity (PI) | Design errors and omissions | Engineering consultant, IE | Set by the contract and the lender |
| Workmen’s Compensation | Worker injury and death during construction | EPC contractor | Per Workmen’s Compensation Act, 1923 |
| Third-Party Liability | Damage to third-party property during construction | EPC contractor | Set by the contract and the insurer |
| O&M Comprehensive | Operational damage post-commissioning | Developer or O&M contractor | Replacement value of plant |
What Lenders Require for LD and Insurance
Lenders set their own contract conditions, so the figures below are not fixed by any regulation or by one lender’s published standard. Ask the lender for its requirements in writing before you sign. Typical headings to check:
- Schedule LD: rate and cap as agreed with the lender, with no FM exclusion for grid availability or equipment supply
- Performance LD: basis and cap as agreed with the lender for sustained yield shortfall
- LD cap: as agreed with the lender, for delay and performance combined
- PI insurance: minimum cover per event and how long the policy must be maintained, as set by the lender
- Performance bond / BG: size, issuing bank and validity period as set by the lender, normally running through the defect liability period
- CAR + ALOP: whether required, and whether the lender must be named as additional insured
Many LD disputes start with vague delivery terms. Our solar design SLA and turnaround guide shows how to write measurable delivery commitments, and the bid-stage engineering checklist for solar EPCs covers the risks to price before you sign.
How Heaven Designs Helps
Heaven Designs works to contracts with defined delivery milestones and a written scope of work. Every engineering deliverable is produced to a defined scope of work that specifies completion criteria, making LD triggers, if they arise, unambiguous.
Heaven Designs covers the engineering and insurance documentation side of the contract; EPCs that also need installation and commissioning capacity under the same performance bond can pair this with Heaven Green Energy’s solar EPC services.
- Solar Rooftop Detailed Engineering Design, IFC-grade deliverables with clear revision control for lender review
- Bankable PVsyst Reports, Yield studies with full methodology disclosure, reducing the risk of a yield-based LD dispute
- Electrical CEIG Drawings, CEIG-ready drawings, reducing the risk of regulatory-rejection disputes
- MW-Scale Project Management Consultancy, Owner’s engineer service that reviews EPC contract terms, including LD and insurance provisions, before financial close
- Download a sample deliverable, See the scope and format of typical engineering deliverables
Contact us to discuss MSA terms, insurance requirements, and how Heaven Designs structures engineering contracts for lender-financed projects.
FAQ
What is the difference between LD and a penalty in a solar contract?
Liquidated damages are a pre-agreed, genuine estimate of the loss a party will suffer from a specific breach. A penalty is a sum disproportionate to the expected loss, designed to punish rather than compensate.
Under the Indian Contract Act, 1872, and US contract law (Uniform Commercial Code), courts enforce LD clauses but may strike down penalty clauses as unenforceable. In solar contracts, ensure your LD amounts can be justified as a reasonable pre-estimate of actual revenue loss, not a punitive amount.
Is professional indemnity insurance the same as contractor all-risk insurance?
No. PI (professional indemnity) insurance covers errors and omissions by the design professional, it applies when a design mistake causes financial loss. Contractor all-risk (CAR) insurance covers physical damage to the work in progress during construction, it applies when a storm damages the partially installed structure.
Both are required in solar project contracts, but they cover entirely different risks and are held by different parties. An engineering consultant must hold PI; the EPC contractor must hold CAR.
What happens if an EPC contractor does not have PI insurance?
If an engineering design error causes underperformance and the EPC (or design subcontractor) does not hold PI insurance, the only recovery available to the developer is through direct litigation against the EPC, which may recover only the value of the EPC contract, not the full 25-year yield shortfall.
For this reason, lenders often make PI insurance a contractual and financing condition. Developers should not accept a design subcontract from an EPC unless the EPC can produce a PI certificate with limits adequate for the project size.
How is the performance bond typically called in Indian solar projects?
A bank guarantee for performance (performance bond) is called by the developer sending a written demand to the issuing bank, citing the breach and the amount being called. The bank must pay within the number of days specified in the BG (typically 5-7 business days for an unconditional BG).
The contractor can dispute the call through injunction proceedings, but an unconditional BG is treated as equivalent to cash and courts are reluctant to grant injunctions on unconditional BGs. This is why contractors negotiate hard on BG terms, and developers should insist on unconditional BGs for performance security.
What is a reasonable LD cap for an engineering-only contract?
For an engineering-only contract (design services, not EPC), a reasonable LD cap is 100% of the engineering contract value for delay LDs, and the same cap applies to any performance-related LD for design errors. This is different from an EPC contract, where the cap is set by the contract and is a share of the full EPC value (the SECI example above caps delay LD at 5% of contract price).
An engineering firm typically charges 0.5-2% of the EPC contract value for design services, capping their LD at the engineering contract value correctly limits their exposure to the fee they receive, not the full EPC value.
How should force majeure be defined in a solar EPC contract?
A well-structured FM clause for solar EPC contracts should list specific qualifying events (natural disasters, war, government sanctions, pandemic) and explicitly exclude events that are foreseeable project risks: grid unavailability, equipment supply delays, labor market shortages, and financing delays.
For SECI projects, the FM clause should align with the FM definition in the PSA, the developer cannot pass on more FM relief to the EPC than the developer receives from SECI. See the solar engineering workflow guide for a broader discussion of contract structure for Indian EPC projects.
Does Heaven Designs carry PI insurance?
Ask about PI insurance at the scoping stage. Whether cover is in place, what it includes and the policy limits should be confirmed in writing for each engagement, not assumed from a website.
For lender-financed projects where the lender needs a PI certificate for the LDED package, raise it with Heaven Designs before the contract is signed so the requirement is written into the scope.