CAPEX vs OPEX Solar
CAPEX vs OPEX is the solar procurement choice: pay for and own the plant (all savings and duties yours) versus hosting a developer-owned plant and buying its units at a contracted PPA rate — capital versus commitment, with very different 10-year economics.
Why it matters on an MEPF project
CAPEX maximises value for owners who can deploy capital: the full tariff saving accrues to you, along with accelerated-depreciation benefits for tax-paying entities — at the price of owning performance risk (mitigated by warranties, generation guarantees and a real AMC). OPEX converts solar into an operating expense: zero capex, developer carries performance, you pay a PPA rate below your tariff — at the price of a long contract whose escalations, exit clauses and buyout schedule deserve legal-grade reading.
The honest comparison is a 10–15 year TCO on your numbers: tariff trajectory, PPA escalation, tax position, cost of capital, and what the year-12 inverter costs under each structure. Rules of thumb mislead here because the drivers (tax appetite, capital cost) differ enterprise to enterprise — this is a CFO decision wearing an engineering costume.
How it's specified in practice
| Parameter | Typical / working position | Governing reference |
|---|---|---|
| Capital | CAPEX: yours upfront · OPEX: none | structure |
| Savings share | CAPEX: full tariff delta · OPEX: tariff minus PPA rate | contract |
| Tax treatment | CAPEX: depreciation benefits to owner · OPEX: opex deduction | tax position (verify with your CA) |
| Risk & exit | CAPEX: performance risk yours · OPEX: PPA term, escalation, buyout schedule | contract terms |
Common mistakes
- Comparing year-1 cash flows instead of contract-life TCO.
- Signing OPEX escalation clauses nobody modelled.
- CAPEX bought without generation guarantee or AMC — ownership without protection.
- Ignoring buyout mechanics until you want the plant.
Related on this site
Frequently asked
Which saves more money?
For capital-rich, tax-paying industrials, CAPEX usually wins on TCO; OPEX wins on balance-sheet neutrality and transferred risk. Our CAPEX-vs-OPEX calculator runs the crossover on your tariff and rates.
What should I scrutinise in an OPEX PPA?
Escalation formula, term and lock-in, generation commitments and shortfall remedies, O&M scope, buyout schedule, and roof-licence terms. The rate gets the attention; the clauses carry the risk.
Standards referenced: contract-defined; tax positions verified case-wise