A contract clause says your solar project's output must be verified by an ASTM E2848 capacity test — but who is actually allowed to run it? The short answer surprises most people facing the requirement for the first time: the standard does not say. ASTM E2848 defines the test method — the data, the filtering, the regression — not the tester. There is no license, certification, or accreditation for performing it.

That means the practical question is not "who is qualified on paper" but "whose result will the other side of your contract accept" — and that is decided by your contract, not the standard. (For what the method itself involves, see our ASTM E2848 capacity testing guide.)

Who Typically Runs the Test in Practice

The EPC or installing contractor. The most common case. EPC contracts usually make passing the capacity test a condition of substantial completion, and place the burden of demonstrating performance on the contractor. The EPC runs (or commissions) the test; the owner — often through an owner's engineer — reviews and accepts the result. If you are an EPC with this obligation and no in-house analysis capability, this page is probably why you are here.

An independent engineer or consultant. When the owner, a lender, or an investor wants a result at arm's length from the party being tested, they bring in a third party — typically an engineering consultancy. Some contracts name this requirement explicitly ("performed or verified by an independent engineer"); many do not.

The owner's or asset manager's own team. Owners run capacity tests outside of commissioning too: verifying performance before an acquisition closes, after major repairs, or when production numbers look off. Here there is often no counterparty to satisfy, and the test is run in-house as a matter of course.

Whoever executes it, the result stands or falls on the same thing: whether the method followed the standard and the report documents it defensibly. A test run by the "right" party with an undocumented filtering process is weaker than a test run by anyone with a report that shows its work.

What the Contract Actually Requires

Before deciding who runs your test, read the performance exhibit (sometimes a "performance test protocol" or acceptance-testing appendix). Look for four things:

  1. The method reference. Usually "ASTM E2848" by name, sometimes with a specific edition. Some contracts also pair it with a second, separate requirement — an availability test — at the same milestone.
  2. The acceptance criterion. A capacity ratio threshold (e.g., measured capacity must reach 95–97% of the model's expected capacity). This is the number the whole exercise produces.
  3. Who executes and who accepts. Many contracts are silent on the executor and explicit about review — the owner's engineer gets the report and the underlying data. Silence on the executor means you may choose, as long as the reviewer can verify the work.
  4. Prescribed test conditions. Some exhibits fix reporting conditions, filtering parameters, or the test window; others defer to the standard's defaults. This determines how much configuration the test needs.

If the exhibit explicitly requires an independent third party, note whether it names a firm or just requires independence — that distinction decides which of the routes below are open to you.

Your Three Options

If the test has landed on your desk, there are three realistic ways to get it done — compared in detail, with prices, in our capacity test cost guide:

  1. Hire an engineering consultant ($3,000–$5,000+ per site). They run everything and deliver a report under their name.
  2. Run it in-house with purpose-built software (from $599). You do the work; a platform like HelioTest enforces the method and generates the report. See plans and pricing.
  3. A managed test — we run the test on the HelioTest platform against your contract's requirements and you receive the full deliverable package. Described on the managed testing service page.

A Simple Self-Assessment

Route yourself with one question: are you comfortable working with a CSV of your monitoring data, and do you have the plant's PVsyst model?

  • Yes to both → run it yourself with software. The method's mechanics — filtering, regression, reporting conditions — are handled by the platform, and you keep the per-test cost at a fraction of outsourcing. There is a free tier to try it on your own data first.
  • No, I want it done → a managed test. You provide monitoring access and the plant model; the test, QA, and report are handled for you, typically within 3–5 business days of data receipt.
  • My contract demands a specifically named independent firm → a traditional consultant is your route. Whether a HelioTest-managed test satisfies a general independence requirement depends on your contract's wording — bring the clause to a scoping call and we will tell you honestly whether we fit it.

Not Sure Which Applies to You?

That is exactly what a scoping call is for. Bring the contract's test exhibit; in 30 minutes we will walk through what it requires, whether your monitoring data supports it, and which of the three routes makes sense for your situation — even if the answer is not us.

Book a scoping call

Or start with the deliverable: download a complete sample ASTM E2848 capacity test report to see what your counterparty's engineer will expect.