A solar PPA is a 15–25 year binding contract that affects your property and your electricity cost. This guide walks through 10 key clauses for C&I factory owners — what each means and the question to ask your lawyer before signing, plus 5 FAQs. (Educational, not legal advice.)
This article is for educational purposes only and is not legal advice. A PPA is a long-term (15–25 year) binding contract that affects your property — always have a licensed Thai lawyer review the actual document before signing. CapSolar is not a law firm; we share what we see in real C&I project negotiations so you can brief your own counsel more effectively. Regulatory items (e.g. the Direct PPA pilot) are in draft and may change.
A private/corporate solar PPA in Thailand is typically a 15–25 year agreement in which a developer owns and operates the rooftop system and sells you the electricity it generates. Unlike the standard-form PPAs from EGAT/MEA/PEA, which generally do not allow for much negotiation, a private rooftop PPA is between two private parties, so there is genuine room to negotiate. The clauses that most affect a factory owner are: term, tariff & escalator, minimum-purchase (take-or-pay), performance/availability, force majeure vs default, early termination & buyout, end-of-term asset transfer, roof/land lease & mortgage covenants, transfer-on-sale, and change-in-law — all of which your lawyer should review.
New to PPA? Start with What Is a PPA. Deciding PPA vs buying outright? See PPA vs EPC.
The number of years you must buy power from the developer. Typical Thai private solar PPAs run 15–25 years; some Thai-market self-investment-vs-PPA explainers cite 10–20 years (ranges seen in the market, not a fixed rule).
Does the term match the realistic remaining life of my roof and my business plan for this site? What are my options if I want to exit early (see the buyout clause)?
The per-kWh price (usually a discount versus your current grid tariff) and the annual escalator (a fixed % the price rises each year). Thai-market explainers commonly describe a discount of roughly 10–30% versus the current grid rate (vendor-quoted market ranges, not a guarantee). We do not state a specific escalator % — it is per-contract.
Is the escalator fixed or indexed? Over the full term, does the escalating PPA price stay below my projected grid tariff (see factory electricity cost)? What happens to the price if the grid Ft charge falls?
A clause obliging you to buy (or pay for) a minimum amount of electricity each month regardless of how much you actually use.
Are the minimums "not excessive and easily managed in light of anticipated future use"? What happens if I cut production, relocate a line, or shut down for retooling?
The developer's promise on how much the system will generate or be available, and the remedies if it underperforms. There is no Thailand-specific statutory figure for this, so treat it entirely as questions.
Is there a guaranteed annual kWh or availability %? What is the compensation if it underperforms, and who measures it? (See what normal output looks like via factory solar sizing.)
Distinguishes uncontrollable events (force majeure) from a party's breach (default). A point to watch is the right to terminate if neighbouring obstructions (new buildings, trees) render the system ineffective.
What counts as force majeure vs default? Can I exit if shading from a new neighbouring building kills my output? Who bears the risk during a prolonged outage?
What it costs to end the PPA before the term, and any option to buy the system out early. We do not state a specific buyout figure — it is per-contract. (Separately, on the utility-interconnection side, the distribution utility may levy a penalty for breach of the grid PPA; that is a utility-grid matter, NOT the private PPA buyout cost — have your lawyer keep the two distinct.)
Is there a published buyout schedule (declining over time)? Is the early-termination fee a clear formula or open-ended? Have your lawyer keep any utility-grid penalty clearly separate from the private PPA buyout.
What happens to the system when the PPA ends — typically ownership transfers to you, often at no extra cost (per Thai-market explainers; secondary sources say "many PPAs" do this — verify in your own contract).
Does ownership transfer to me automatically and free of charge? In what condition (refurbished? remaining warranty?)? Or does the developer remove the system?
The developer occupies your roof for 15–25 years. Check that the install won't breach your lease, won't be wrongly classified as a permanent fixture, and review mortgages/encumbrances — whether an existing property mortgage affects the developer's collateral rights or creates lender conflicts.
If I lease (not own) my building, does my lease allow this for the full term? Will my bank/mortgagee consent? Is the system a "fixture" that complicates a future sale or refinance?
Whether the PPA obligation passes to a new owner if you sell the building, and on what terms. Assignment / transfer-on-sale is general contract practice, so frame it as questions for your lawyer.
Can I assign the PPA to a buyer of the property? Does it make my building harder to sell? What consents are needed?
A good PPA should "envision how new rules affecting the transaction will be addressed." Thailand's regulatory landscape is actively shifting — the ERC's draft Direct PPA / Third-Party-Access (TPA) regime (NEPC-approved 2,000 MW pilot, June 2024; ERC draft regulation Oct 2025) could change what's possible (draft, subject to change). Step-in rights (a lender's or developer's right to step into the contract on default) are a financing-side clause — have your lawyer explain them.
Who bears the cost if the law changes (e.g. new wheeling charges, the Direct-PPA pilot)? Do lenders have step-in rights, and how would that affect me?
Eight action-oriented steps to prepare before you sign — and to brief your lawyer thoroughly.
Confirm whether this is a private PPA (negotiable) or a utility standard form (largely fixed).
Map the full term against your roof life + business horizon.
Model the escalating tariff vs your projected grid cost across the whole term.
Pressure-test the take-or-pay minimum against your worst realistic production year.
Get the early-termination/buyout schedule in writing.
Confirm end-of-term ownership transfer terms.
Clear roof-lease / mortgagee consent before signing.
Have a licensed Thai lawyer review the contract — this checklist prepares you to brief them, it does not replace them.
This article is prepared by Frank Lee, Founder of CapSolar, which has delivered 80+ MWp of commercial & industrial solar across 150+ projects for 100+ clients. CapSolar is not a law firm; we share what we see in real C&I PPA negotiations so you can brief your own counsel.
Reviewed by: CapSolar Research Team | Updated: Jun 2026
CapSolar has delivered 80+ MWp of commercial solar across 150+ projects. We help you understand PPA structures and prepare to brief your lawyer — free consultation.
Reminder: this is educational information, not legal advice. Always have a licensed Thai lawyer review the actual contract before signing.