Project Managing the ASTM Capacity Testing Process

ASTM Capacity Testing is notorious for dragging out timelines for utility solar construction projects, delaying final EPC payments, and putting projects in a state of limbo. Our “Instant Capacity” process can give you capacity testing results in a few moments and dramatically speed up the performance engineering side of the equation. However, no amount of software wizardry can change bad project management decisions, bad weather, or fix a site if it’s not fully functional. On average, projects need to be fully operating and accumulating data for 30-45 days to run a successful capacity test. However, we’ve seen projects become stuck in performance testing phase for 6 months or more. We’ve also seen projects pass with as little as 15 days of data accumulation.

A large part of the difference is how well the project closeout process is managed.

In this article, we help you as a project manager avoid delays, by providing an overview of what to focus on to make sure that your project is ready to test as quickly as possible. Here we lay out what you should consider and when.

Step 1) Before your EPC contract is signed:

Make sure you understand the contract provisions related to ASTM performance testing and the potential risks associated with them.

Most EPC contracts with a requirement for ASTM Performance Testing have an exhibit that describes conditions for the testing. Often these exhibits include clauses that specify very significant liquidated damages if the site underperforms in the capacity assessment.

Additionally, some contract requirements may modify the ASTM testing protocols to make the test harder to pass. We’ve incorporated the most common variations on the test into our system, but we’ve seen some fairly outlandish technical modifications of the original protocols, some of which make it very hard or even impossible for EPCs to pass the test.

We’ve written a separate blog post covering some of the common issues with EPC contract clauses, but ultimately someone on your team needs to understand the ASTM protocol well enough to avoid signing a bad contract. If you don’t have someone on your team with the background necessary, contact us - we offer fee-for-service redline support for ASTM contract clauses.

Step 2) Before the project is complete:

Generate and submit your ASTM E2939 results to your client.

Remember that the first protocol in the ASTM process (ASTM E2939) generates a baseline for the project. It can be completed before the project is built - it simply requires a final PV Syst/production model, which you’ll input into our system (as an 8760 output). Once you’re beyond the point in construction where As-Built changes might impact the production model, you can get ahead by completing half of the capacity assessment process early. If engineering is completed early, many groups will even choose to complete 2939 results for inclusion in the contract as an exhibit - this avoids any possibility of confusion about the baseline for testing later on.

By completing the ASTM E2939 portion early, you give your client plenty of time to review these important results, thus avoiding delays caused on their end. Additionally, you’ll have one less thing to do internally once your project is ready to begin assessing performance.

Step 3) After mechanical completion:

Prioritize critical DAS install activities before demobilization.

We all know that DAS and weather sensor install sometimes takes a back seat toward the end of the project, when everyone’s focus is on getting the project ready to flip the switch and produce power. However, it’s important to understand that the project will likely not be producing any usable data for the capacity test until the monitoring system is fully installed and commissioned. Many projects can stall if an electrical team is demobilized before DAS install is completed.

Step 4) After substantial completion

Prioritize punchlist activities that impact the DAS or production.

Your site has to be operating at 100% to start the clock on the 30-45 days of data collection.

If a single one of your sensors (irradiance, temp, and wind) or meters (CTs/PTs) aren’t working, then you aren’t gathering data.

And if portions of your site aren’t working, you may be gathering data, but it may not provide you with the results you are hoping for.

Prioritizing commissioning the DAS to 100% as soon as the site has AC power is an absolutely critical step to making sure that you are getting the project closed out as quickly as possible. If the DAS and production issues are completed early, you can gather your 30-45 days of data while you finish any remaining punchlist tasks (civil/mechanical remediation, wire management, etc.). It may even be possible to remove capacity testing from your project’s critical path schedule entirely.

Step 5) After testing is complete

Clearly communicate status of capacity testing, along with the the results, methods, and assumptions of your successful ASTM E2848 capacity test to your client and IE so that they can review the results quickly.

The flexibility of the ASTM protocols is what allows them to be applied to project sites with varying equipment and varying climates all over the world. However, that flexibility means that “showing your work” on your ASTM capacity tests is critical to ensuring that they stand up to scrutiny from owners and engineers. At a minimum, reports should include not only the measured site performance and analysis, but also measures of reliability such as p values for all variables, the types of filtering that was conducted on the data, the number of data points that were included/excluded. Additionally, we provide access to “intermediary” and “final” data sets as CSV. This inclusion allows outside engineers to re-analyze the data to validate the conclusions if they so chose. We strongly encourage our clients to simply provide all of the generated information to their clients.

Without a high level of transparency and thoroughness in the initial reporting your ASTM capacity testing results, you risk long periods of back and forth requests for information with clients and independent engineers. By producing comprehensive reports immediately and providing all the data to back it up, our Instant Capacity system avoids not only the long period of time required for manual analysis, but much of that subsequent back and forth.

Additionally, Instant Capacity allows creation of brief explanations of any tests run that don’t generate passing results. Remember “not passing” is not the same as failing the test. Usually the issue is that the site hasn’t produced enough clean data to get results that meet the ASTM standard. By providing your team with a report that explains any data issues caused by weather, inverter clipping, challenging contract clauses, or other factors we enable you to provide regular updates to your client on project status even if the project is taking a while to pass due to issues beyond your control.

Instant Capacity is currently invite only - contact us to join our private beta.