Achieve Solar System Testing, without the Grid

Comrent is providing solutions for mission-critical power testing infrastructure.

What Happens During a Solar Farm Load Bank Test

In order for a solar farm to be commissioned for operations, it must undergo comprehensive load testing. During a load test, the solar system is fully energized to confirm the safety and efficiency of facility operations and to ensure that all inverters are working properly.Facility owners may use a grid connection to energize the new facility to test their equipment and systems, but for many large facilities, grid connection isn’t immediately available when the testing phase needs to begin. Grid power is also subject to potential fluctuations during testing that can lead to inaccurate and prolonged data collection.

With a custom engineered system of generators and load banks, facility owners can achieve full system testing even when the grid isn’t available. These devices deliver a sustainable and predictable power load to enable fully accurate system testing for short and prolonged periods of time. Here’s how the load bank testing process works:


The first step in solar farm load bank testing is scheduling a consultation with your load bank provider of choice. When selecting a load bank rental provider, there are several important qualities to look for. The top three selection criteria you should consider are:

  1. Customized Solutions: All facilities are different, and you should seek a provider to build a customized testing plan tailored to your facility. It is important to find a provider with a broad and diverse inventory of load bank solutions to address your specific needs.
  2. End-to-End Service: Look for a load testing service provider that can plan equipment placement, coordinate end-to-end logistics, provide roll-out/roll-up services and create a safe commissioning project. The more end-to-end services, the more streamlined your commissioning project will be.
  3. Flexibility: Find a proven provider that is able and willing to modify existing load bank equipment or design new solutions to complete your project. Every solar farm is different, so you’ll need a service provider able to accommodate your unique needs.

After selecting your solution provider, share all your project documentation to help them get a better idea of the strategy best suited to commissioning your facility according to your timeline. Factors like the size of your facility, power needs, timelines and equipment specifications will all come into play. Your provider will use this information to present a plan before any groundwork begins.

Delivery & Setup

Once you’ve had a consultation, your load bank provider will compile and ship all the necessary equipment directly to your facility. The setup process involves several key components but can vary according to your specific facility’s needs. The most fundamental equipment is:

  • Diesel generator(s)
  • Load bank(s)
  • Power quality monitors
  • Inverter


To successfully commission a solar PV power plant system, you must provide a steady power source on the utility side of the PV Inverters. A system of load banks and generators can be connected at the main breaker of the substation or one of several combiner boxes on site and activated to simulate the electric load.

Once utility power is simulated in the solar farm, this will activate the internal circuits of the inverters. The solar arrays, which constantly produce power during daylight hours, will then begin to produce power and sync with the power source.

The power system is achieved by providing a generator system rated at 120% of the inverter size. For best results, two paralleled generators are used to deter frequency variation caused by load reduction and application. A comprehensive load bank testing process will:

  • Energize the entire site so available staff can work on different inverter pads simultaneously.
  • Test medium voltage cables buried underground from the substation to the inverter pads.
  • Test tracking systems to ensure the solar system tracks correctly to the sun.
  • Verify array sleep and wake modes to confirm total system functionality.
  • Test inverter performance for efficiency and responses to power fluctuations.


Simulating the grid using load banks ensures the most complete solar farm testing and commissioning process. Once the commissioning process is completed, solar farm owners will be able to:

  • Validate that all components work together, especially inverters.
  • Ensure safe operations.
  • Demonstrate compliance with applicable standards and regulations.
  • Document system performance.
  • Establish performance benchmarks for future maintenance.
  • Reduce the likelihood of future outages.

Tear Down

Once your project is complete, your load bank provider will validate the results and confirm whether commissioning can be approved or if the facility needs modifications or repairs to take place.

Why You Should Partner With Comrent

Comrent provides the world’s most comprehensive load bank and generator solutions for solar PV power plant commissioning. Our equipment delivers the variable, sustained loads required to meet the strenuous 600+ hours of testing mandated by solar regulations. With both resistive and reactive solutions, Comrent’s load banks are the only fleet in the U.S. engineered for solar PV power plants.

With the largest rental inventory of load banks in the nation and 24-hour delivery, Comrent is the global leader in providing load testing services when and where you need them. Our technicians can manage delivering these components and setting up your load bank test. A turn-key solution provider like Comrent will ensure that your operations can proceed as normal almost immediately after testing has finished.

Comrent’s team of experts is ready to help ensure your solar system is successfully commissioned. We are offering a complimentary consultation to review your project and propose the right load bank solution for your requirements. Contact us today.

Contact a power testing equipment expert today

Do you have a question? Connect with one of our experts. Please fill out the form and a member of our team will contact you within one business day.

Call an expert at ComRent today!   888.881.7118
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.