Achieving Commercial Operations in Large-Scale PV Power Systems: Page 6 of 6

Strategies for Success

While we recognize that project team members may need to deviate from their conventional delivery models to accommodate the performance testing means and methods we have described here, our experience shows that such deviation is both necessary and beneficial. Although the solar industry has rigorously optimized system design, engineering, procurement and installation via iteration and continuous improvement, the performance testing process remains relatively immature and is ripe for development.

We have based our perspective on project closeout on the testing and commissioning problems our clients have encountered in the real world, as well as on our (sometimes limited) ability to identify root causes and solutions. While contract closeout problems are unpredictable and usually very complex, our experience is that hard work and high-quality data analysis can solve most of these issues. With adequate monitoring and commissioning documentation, a project team can investigate, diagnose and correct the majority of performance shortfalls within the timeframe of the project schedule. The following is a summary of project closeout practices that have worked well for us.

Say no to secrets. We strongly advocate an open and transparent project delivery model, in which the team shares energy models, design documents, testing target, evaluation methods and commissioning reports. While this approach may not be right for every team, all parties need to recognize that any insistence on secrecy or confidentiality introduces risk. Secrecy impedes troubleshooting. It is a risk to propose keeping other stakeholders in the dark or to accept this secrecy. A transparent and collaborative testing and closeout process works well precisely because it allows the team to find solutions more quickly.

Centralize data. Create a central repository for all relevant project information. This data center should contain any resources that affect, inform or influence performance testing and project closeout. As a general rule, the data center should contain all the information a completely uninformed third party would need to validate or conduct performance testing from scratch without help. This information archive should include commissioning data, testing model, target results with derivations, test evaluation tools, unrestricted access to operational data downloads and backup data for troubleshooting.

Establish a tiger team. Assemble a group of smart people from multiple disciplines to shepherd the project from inception to closeout. The configuration of this team will evolve as the project matures. At the time of performance testing, the closeout team should include agents representing the owner, EPC firm, SCADA provider, inverter supplier, independent engineering providers, design engineering team and party responsible for energy modeling. This team of experts will meet on an as-needed basis during the project development process and on a daily basis during the big push to complete performance testing. Membership  continuity is critical to the team’s success. It is also important to keep all team members fully informed at every step of  the process.

Ready triage teams. Closeout team members must assure they have adequate backup resources available for problem-solving and troubleshooting. It is especially important to have a backup squad available during the run-up to the performance tests, as projects approaching COD cannot wait for a given vendor to assemble an ad hoc squad to solve problems. It is the direct responsibility of each closeout team member to ensure that he or she has the right engineers, programmers or field personnel available at the time of the performance evaluation test.

Conduct preliminary tests. While project schedules often omit this step, it is critical for success. Come test time, everything has to work reliably, accurately and simultaneously. A single stakeholder running behind schedule will delay the test schedule. One wayward sensor will jeopardize the accuracy of the performance evaluation. The failure of any major component will invalidate the test results. These examples illustrate why it is essential to have triage teams at the ready. Conducting a preliminary test run—or a series of runs, if necessary—can potentially save weeks by obviating test period extensions. Preliminary test runs eliminate nuisance problems, provide a forum for multi-disciplinary validation of system operation and significantly speed up the formal testing process.

Keep all eyes on the prize. At the time of testing, the closeout team should meet every day to evaluate preliminary test results, troubleshoot problems and validate operational information. Problems are easy to identify and solve when you make data sets available to all participants, who bring different points of view to bear on the issue. This is the greatest advantage of the process and the most useful part of the open approach to testing. When you have a team of experts dedicated to making a system work, amazing things happen.

Strive for consensus. Those who are used to more-hierarchical methods of project delivery sometimes deride consensus methods as “group therapy.” Our response is simple: What is wrong with group therapy? We all know that things can and do go wrong. Some schedules will slip. Some system will underperform. Some liquidated damages will require negotiation. But these risks are independent of delivery method. The thing we should be concerned about is how we are going to work through these problems. If we all work together, we can fix problems faster, and we can all take pride in a job well done. The overarching goal—and the likely end result—of the open project–delivery process is a shared sense of accomplishment when the project reaches COD.

With mutually agreed upon assumptions, models and test methods, each team participant can revisit individual processes based on testing outcomes. The owner and developer can apply results to future projects and adjust business models accordingly. EPC teams can perform subsystem analyses to better predict under- or overperforming systems. Independent engineers can review and analyze reliable data sets. Regardless of any individual outcome, the information gathered from an open testing process is valuable for everyone involved, especially future owners and operators. There is no better foundation for long-term viability than an asset that is fully documented and complete when it enters commercial operations.


Anastasios Hionis, PE / PV AMPS / Sacramento, CA /

Mat Taylor / PV AMPS / Paradise, CA /

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