Achieving Maximum System Output with Solar Commissioning

Solar commissioning has several different definitions:

  • A homeowner can “commission” a new solar photovoltaic (PV) system by hiring a professional installer.
  • A solar sales representative might receive a “commission” – based on how many PV systems they sell.

This article explores a specific type of solar commissioning – one that can help large-scale PV projects achieve their full potential by delivering predictable financial and environmental returns for their owners.

Read on to learn what solar PV commissioning is, how it works, and why it matters.

What Is Solar Commissioning?

Solar commissioning is the process of configuring and verifying that all the PV components in each project are properly designed, installed, and optimized per the expected performance requirements of the solar system owner (or investor).

It’s technically possible to do this at the residential level. Most installers conduct various types of solar field acceptance tests when setting up PV panels for homeowners. Solar commissioning is often reserved for larger commercial installations or utility-scale PV facilities. Tiny performance anomalies can have a huge impact when those losses compound across thousands of solar panels and other PV components.

Most solar projects over a certain size are customized and designed from the ground up. As such, they don’t necessarily benefit from the automatic warranty protection that many consumer goods receive.

Technicians check solar panels for proper operations

Comprehensive solar PV commissioning overcomes these problems by providing system owners with performance guarantees that allow them to better forecast returns from their clean energy investments.

What Are the Benefits of Solar Commissioning?

Most solar PV facilities are profit-generating enterprises, with investors and owners trying to maximize their returns. And the primary function of solar commissioning is to guarantee that the facility meets the operational requirements of the investors.

More specifically, solar PV commissioning allows one to:

  • Verify that all PV components are installed per manufacturer guidelines.
  • Ensure that the PV system has been installed per all engineering and design requirements.
  • Identify and correct any potential defects, energy losses, or performance issues within the solar project.
  • Enhance the financial security and ROI predictability of the entire clean energy investment.

Handoff from the engineering, procurement, and construction (EPC) team to the operations and maintenance (O&M) team is not successful unless all performance evaluations and acceptance tests are satisfied by the project’s completion. The same is true for grid-connected solar projects that must meet any number of local regulations.

There’s another benefit of PV commissioning.

Optimizing solar facility performance allows one to more accurately calculate the PV project’s expected energy production, which in turn, helps to determine critical metrics like profitability, payback periods, ROI’s, and Power Purchase Agreement (PPA) compliance. In addition, solar PV commissioning helps to establish benchmarks against which to measure future performance. In fact, it’s impossible to determine whether a facility is underperforming or not without having a baseline.

What Is Solar Recommissioning?

Solar commissioning is a one-off job for newly built PV facilities. But for existing solar assets, a lower level of commissioning can help keep facilities in optimal condition through various preventive maintenance protocols. For example, solar “recommissioning” helps identify issues that are easily missed by direct current (DC) overbuild within the system. Or you might discover hotspots within the panels or corroded electrical wiring somewhere in the facility.

Either way, preventive maintenance is often cheaper than emergency repairs, since occasional inspections allow you to isolate and fix issues before they grow into much larger and more expensive problems that lead to decreased production, savings, and earnings.

What Does Solar PV Commissioning Involve?

The basic mechanics of PV technology remain the same – whether one is installing rooftop panels on a home or designing a sprawling solar farm meant to serve a nearby community. If you open the hood, you’ll find PV modules, racking, wiring, combiner boxes, conduits, inverters, monitoring systems, and routers. There may also be on-site storage capabilities and electric vehicle charging.

As such, field testing is always important during the installation phase. And in fact, the US Department of Energy has a free solar commissioning checklist designed to help residential installers test and troubleshoot the most common issues.

But as the size of the system grows, so too do the sheer number of PV components involved. Therefore larger commercial and industrial-scale projects require a more methodical solar PV commissioning approach that involves diligently inspecting every component in a prescribed order (like the one below).

1. Electrical Testing

This involves inspecting all the electrical components in the PV system, including the wires, panels, inverters, and even substations. The primary goal of electrical testing is to verify that every component has the correct current, voltage, and amperage – both individually and across the entire facility.

2. Mechanical Testing

Most solar PV facilities have zero moving parts. But mechanical inspections of all racking, mounting, and other structural components of the system are essential. This is true for solar projects installed in areas with high winds or seismic activity.

3. Performance Evaluations

With performance evaluations, you measure the expected (or modeled) output of the facility to its actual output (after adjusting for things like weather). This performance ratio (or “PR”) helps to establish a baseline when forecasting both the long-term energy output and financial returns of the solar project.

4. Corrections Reporting

The final step involves providing the facility manager or system owner with a report detailing recommended corrective actions for any issues discovered during the previous testing and evaluation stages.

Example Solar Commissioning Checklists

Because most large-scale solar projects are customized from the ground up, there is no universal solar commissioning checklist that will work across all PV facilities. The broad strokes might stay the same, but the actual optimization and evaluation processes vary based on the facility’s size, location, and what technology is being used. For example, the steps for testing and repairing string inverters are very different from the troubleshooting protocols reserved for microinverters.

Moreover, there are often strict regulatory hurdles throughout the process, each with its own compliance requirements. In addition to utility permission to grid-connect, larger solar projects must also pass extra permitting inspections from the local authority having jurisdiction (AHJ) throughout the PV development, installation, and completion stages. And in the case of utility-scale projects, regulators might also request environmental impact analyses as well.

As you can see from the examples below, solar commissioning checklists can be surprisingly short or many pages long:

The True Impact of Solar Commissioning on Long-Term Financial Performance

The solar PV commissioning process is sometimes baked into the installation cost of the PV system itself. Consequently, this cost is often overlooked as a priority standalone item. And system owners who recognize solar commissioning as an optional added cost might be tempted to forgo the extra expense. After all, if the completed solar project is operationally functional and working well enough, why pay more than necessary?

But again, tiny problems can quickly mushroom into larger ones if left unaddressed. And understanding this helps to reposition both solar commissioning and preventative maintenance as “investments” as opposed to traditional “expenses.” Equally important, solar PV commissioning is critical in determining the performance ratio of the system. Without this initial baseline, forecasting returns is impossible. It also becomes harder to identify opportunities to optimize performance or mitigate bottlenecks.

One final word of warning.

As a PV system owner or project manager, you may be tempted to reduce or eliminate solar commissioning costs by outsourcing the job to local regulators during inspections. However, city and utility officials do not typically inspect PV systems for performance or analytics. Rather, they focus on things like compliance and safety. And quite often, solar projects will receive the green light from regulators – even if they suffer from severe underperformance issues.

A Different Approach to Solar PV Commissioning

One of the challenges of solar commissioning is how specialized many aspects of installation, maintenance, and repair have become as technology continues to mature.

This trend already exists in the residential market, with many installers now struggling to update solar monitoring equipment for their customers before the major telecoms stop supporting 3G wireless technology. The average residential installer is also ill-equipped to troubleshoot on-site storage solutions or EV-charging ports.

As the size of the PV system grows, so do the challenges involved with finding the right technician(s) for the job – whether the goal is:

  • Solar commissioning
  • Preventative maintenance
  • Emergency repairs

365 Pronto offers an innovative approach to this growing problem.

We carefully analyze your solar installation or facility to develop a unique “DNA” profile – based on variables like your PV project’s size, location, age, and components. This unique profile instantly matches whatever service or repairs you need with certified technicians. Our technician matches ensure exact skills, training, and expertise are required to complete the job – quickly and affordably.

If you’re looking for a bespoke team to ensure that all the solar components in your bespoke PV system have been designed, installed, tested, and maintained according to your own operational requirements, learn how 365 Pronto can help.