What Is Force Majeure (Solar)? Definition & Guide

Key Takeaways

A force majeure clause in a solar contract excuses delays and non-performance caused by events genuinely outside either party’s control
Common triggers include hurricanes, earthquakes, pandemics, trade tariffs, government moratoriums, and raw material shortages
The clause must be explicitly written into the contract — courts will not imply force majeure protections if the language is missing
COVID-19 and subsequent supply chain disruptions tested force majeure provisions across thousands of solar PPAs and EPC agreements starting in 2020
Proper drafting requires a defined list of qualifying events, a notice period (typically 5–15 days), a mitigation obligation, and a termination trigger if the event exceeds a set duration
Financial exposure from force majeure events can be calculated by combining daily carrying costs, lost revenue, and penalty clauses over the duration of the disruption

What Is Force Majeure in Solar Contracts?

Force majeure (French for “superior force”) is a contractual provision that temporarily or permanently relieves one or both parties from performing their obligations when extraordinary circumstances make performance impossible, impracticable, or illegal. In the solar industry, a force majeure clause in a solar contract protects developers, EPC contractors, offtakers, and equipment suppliers when events outside anyone’s control disrupt project timelines and budgets.

Unlike general contract law doctrines such as frustration of purpose or impossibility, force majeure is a creature of contract. It only applies if the agreement explicitly includes the clause and defines what qualifies as a triggering event. A solar project force majeure claim that lacks contractual backing will almost certainly fail in court.

A well-drafted force majeure clause solar agreement protects all parties from unforeseen disruptions while maintaining accountability for risks that can reasonably be managed. According to the Solar Energy Industries Association (SEIA), force majeure provisions became the most frequently negotiated clause in solar contracts following the COVID-19 pandemic and the U.S.–China trade disputes that disrupted module supply chains.

Types of Force Majeure Events in Solar

Environmental

Natural Disaster Events

Hurricanes, tornadoes, earthquakes, floods, wildfires, and severe weather that physically damages project sites, delays construction, or makes job sites inaccessible. These are the most straightforward force majeure triggers and are rarely disputed when properly documented with meteorological or geological evidence.

Regulatory

Government / Regulatory Events

New tariffs, import bans, sanctions, permitting moratoriums, grid interconnection freezes, and changes in law that make project completion illegal or economically unviable. The Section 201 and Section 301 tariffs on solar panels imported to the U.S. triggered numerous force majeure claims between 2018 and 2024.

Logistics

Supply Chain Disruptions

Port closures, shipping container shortages, raw material scarcity (polysilicon, silver, copper), factory shutdowns, and transportation strikes. The global polysilicon shortage of 2021-2022 caused module delivery delays of 3-6 months, forcing renegotiation of hundreds of solar EPC contracts.

Health / Safety

Pandemic / Public Health Events

Government-mandated lockdowns, quarantine orders, workforce unavailability due to illness, and public health emergencies that halt construction activity. COVID-19 was the first global pandemic to systematically trigger force majeure clauses across the solar industry at scale.

Force Majeure Impact Matrix

This table summarizes how different force majeure events typically affect solar projects, their expected duration, and the contractual remedies that apply.

Force Majeure Event	Impact on Solar Project	Typical Duration	Contractual Remedy
Hurricane / Major Storm	Physical site damage, construction halt, equipment destruction	2–8 weeks	Timeline extension + insurance claim for damaged equipment
Earthquake	Foundation and racking damage, structural reassessment required	4–16 weeks	Timeline extension + redesign costs shared per contract terms
Government Tariff / Import Ban	Module cost increase of 15–40%, delivery delays	6–24 months	Price adjustment clause or contract termination right
Permitting Moratorium	Full construction stop until moratorium lifts	3–12 months	Timeline extension; termination if moratorium exceeds cap
Polysilicon / Material Shortage	Module delivery delays of 3–6 months, price spikes	3–9 months	Timeline extension + cost escalation sharing formula
Pandemic Lockdown	Workforce unavailability, site access restrictions	1–6 months	Timeline extension; daily carrying costs absorbed per allocation clause
Grid Interconnection Freeze	Completed system cannot energize or generate revenue	2–12 months	Timeline extension; lost revenue compensation if utility-caused
Wildfire / Flood	Site destruction, evacuation orders, access road closures	2–12 weeks	Timeline extension + force account billing for emergency work

Calculating Force Majeure Financial Impact

When a force majeure event occurs, both parties need to quantify the financial damage to negotiate fair remedies. The core calculation combines the ongoing costs of maintaining the project in a suspended state with the revenue that would have been generated during the delay period.

Delay Cost Formula

Delay Cost = (Daily Carrying Cost + Lost Revenue) x Force Majeure Duration (days)

Where:

Daily Carrying Cost = Interest on construction financing + insurance premiums + site security + equipment storage fees, divided by 365
Lost Revenue = Expected daily energy production (kWh) x offtake rate ($/kWh) for operational projects, or expected milestone payment value for projects under construction
Force Majeure Duration = Number of calendar days from the date the force majeure notice is delivered to the date normal performance resumes

Example: A 5 MW commercial solar project with $8 million in construction financing at 6% interest, $200/day in insurance and security costs, and an expected offtake rate of $0.07/kWh producing 22,000 kWh/day:

Daily Carrying Cost = ($8,000,000 x 0.06 / 365) + $200 = $1,315 + $200 = $1,515/day
Lost Revenue (if operational) = 22,000 kWh x $0.07 = $1,540/day
90-day force majeure event = ($1,515 + $1,540) x 90 = $274,950 total delay cost

This number determines whether the parties negotiate a timeline extension, a price adjustment, cost sharing, or contract termination.

COVID-19 and Supply Chain: The Force Majeure Stress Test

The COVID-19 pandemic, followed by the global polysilicon shortage and shipping container crisis of 2021-2022, tested force majeure clauses across the solar industry like no previous event. SEIA reported that over 60% of U.S. solar projects experienced material delays during this period. Many contracts drafted before 2020 lacked pandemic-specific language, leading to prolonged disputes over whether COVID-19 qualified as a force majeure event. The lesson was clear: generic “acts of God” language is not sufficient. Modern solar project force majeure clauses now explicitly list pandemics, government shutdown orders, and supply chain disruptions as qualifying events. Developers using solar proposal software should ensure their standard contract templates reflect these updated provisions.

Key Elements of a Solar Force Majeure Clause

A force majeure clause in a solar contract must address five elements to be enforceable and practical:

Defined Triggering Events. List specific categories (natural disasters, government actions, pandemics, supply chain failures) plus a catch-all for events “of similar nature beyond the reasonable control of the affected party.” Avoid relying solely on the catch-all — courts interpret vague language narrowly.
Notice Requirements. The affected party must notify the other party within a set period (typically 5-15 business days) after the force majeure event begins. The notice should describe the event, its expected impact on performance, and the estimated duration. Late notice can waive the right to claim force majeure relief.
Mitigation Obligation. The affected party must take commercially reasonable steps to minimize the impact. A contractor who stops all work during a supply chain delay, when other project tasks could proceed, may lose force majeure protection for the entire project timeline.
Relief Provisions. Specify what relief applies: timeline extension only, cost sharing, price escalation, suspension of liquidated damages, or a combination. The contract should state whether the non-affected party owes any compensation during the suspension period.
Termination Trigger. If the force majeure event continues beyond a defined period (typically 180-365 days), either party may terminate the contract. Define the financial settlement upon termination: payment for work completed, return of deposits, disposition of materials already procured.

Practical Guidance

Force majeure provisions affect every stakeholder in a solar project differently. Here is role-specific guidance for drafting, invoking, and responding to force majeure claims.

Design for resilience from the start. Use solar design software to model worst-case scenarios including equipment substitution. If a specific panel model becomes unavailable due to a supply chain disruption, having an alternative layout ready reduces the force majeure delay period.
Document weather and site risk factors. Include shading analysis, flood zone data, and wind load calculations in your design package. This documentation supports force majeure claims when natural disasters damage a project site.
Maintain version-controlled design files. If a force majeure event requires a redesign (different equipment, adjusted layout), you need the original design on record to calculate the cost and timeline impact of the change.
Pre-approve alternative equipment in the contract. Work with procurement to list two or three acceptable panel and inverter models in the contract specifications. This reduces the need to invoke force majeure for equipment substitution.

Send force majeure notices immediately. Do not wait to see if the disruption resolves itself. Most solar contracts require notice within 5-15 business days, and late notice can forfeit your right to relief entirely.
Document everything during the force majeure period. Keep daily logs of what work is possible, what is blocked, what mitigation steps you are taking, and all communications with suppliers and subcontractors. This record is critical if the claim is disputed.
Continue all unaffected work. A supply chain delay on panels does not excuse stopping electrical rough-in, trenching, or racking installation. Courts and arbitrators expect the affected party to mitigate by continuing every task that can proceed.
Review subcontractor force majeure pass-through. Ensure your subcontractor agreements contain matching force majeure provisions. If your EPC contract grants you timeline relief but your sub agreements do not, you may still owe liquidated damages to subs for the delay.

Explain force majeure provisions in plain language. Customers rarely understand legal terminology. Walk them through what events could delay their project, how timelines adjust, and what protections they have. Transparency during the sale prevents disputes later.
Use proposals to set realistic timeline expectations. When generating proposals with solar proposal software, build in buffer time for potential disruptions rather than quoting best-case timelines that require force majeure extensions when anything goes wrong.
Proactively communicate during force majeure events. If a force majeure event affects an active customer project, contact the customer within 48 hours with a clear explanation, expected impact, and updated timeline. Silence during disruptions destroys customer trust.
Know when force majeure does not apply. Cost increases alone, subcontractor availability issues, or internal business problems (cash flow, staffing) are not force majeure events. Misrepresenting these as force majeure to a customer is a breach of contract and damages your credibility.

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Sources & Further Reading

SEIA Research & Resources — Industry data on solar project delays, contract trends, and supply chain disruptions affecting the U.S. solar market
DOE Solar Energy Technologies Office — Federal research on solar project development risks including regulatory and supply chain challenges
UCC Article 2 — Sales (Cornell Law) — Legal framework for commercial impracticability, the statutory cousin of contractual force majeure
ABA Forum on Construction Law — Legal guidance on force majeure drafting and enforcement in construction and energy contracts

Frequently Asked Questions

What qualifies as a force majeure event in a solar contract?

A force majeure event in a solar contract is any extraordinary occurrence beyond the reasonable control of the affected party that prevents or materially delays project performance. Typical qualifying events include natural disasters (hurricanes, earthquakes, floods, wildfires), government actions (new tariffs, import bans, permitting moratoriums), pandemics and public health emergencies, wars or civil unrest, and supply chain disruptions (material shortages, port closures, shipping delays). The event must be unforeseeable, unavoidable, and not the result of the affected party’s negligence. Ordinary business risks such as cost overruns, labor shortages, or subcontractor disputes generally do not qualify.

Does a force majeure clause automatically apply if there is a supply chain delay?

Not automatically. A supply chain delay only triggers a force majeure clause if the contract specifically lists supply chain disruptions as a qualifying event and the delay meets the clause’s requirements, which typically include being beyond the party’s control, unforeseeable at the time of contracting, and not resolvable through commercially reasonable mitigation efforts. If a contractor could have sourced panels from an alternative supplier at a reasonable cost but chose not to, the claim may fail. The affected party must also follow the notice requirements in the contract, usually within 5-15 business days of the disruption.

How long can a force majeure event last before the solar contract can be terminated?

Most solar contracts set a maximum force majeure duration of 180 to 365 days. If the event continues beyond this period, either party typically has the right to terminate the agreement without penalty, subject to a financial settlement for work already completed, materials procured, and deposits paid. Some contracts use a stepped approach: after 90 days, the parties must enter good-faith renegotiation; after 180 days, either party may terminate. The specific termination trigger should be clearly defined in the contract. Without a cap, a force majeure event could leave both parties in indefinite limbo with mounting carrying costs.