Testing Microgrid Solar Inverters

Big tax incentives, broader market reach, and innovative technologies have driven down the costs of solar power development. With solar costs getting closer to grid parity, the use of solar power within microgrids has become a more viable option and continues to see growth in the United States. The Solar Energy Industries Association estimates a new solar installation occurs every 3.2 minutes. With this growth, the group predicts solar use will triple in the U.S. by 2018.

The conundrum is ensuring your microgrid’s solar operation functions as intended and delivers anticipated solar inverter conversion efficiency. There are accurate methods of conducting solar inverter testing within your microgrid to provide the highest performance levels.

The Testing Process for Microgrid Solar Inverters

Before you begin a solar inverter testing project, you will need to answer some fundamental questions:

  • What is your Commercial Operation Date (COD)?
  • When will grid power be provided?
  • How many inverters are in the facility?
  • What is the interconnection facility?
  • Who is responsible for the system startup?

In renewable energy commissioning projects like solar farms, load testing can involve many complexities.For example, you must test each solar inverter employed at a utility-scale photovoltaic (PV) site for safety and functionality. This testing is required before connecting to local and regional distribution networks.

You can perform commissioning tests using load banks even if the grid is unavailable. In fact, load banks offer a preferred testing method compared to using the national grid. Testing with load banks meets IEEE standards for inverter testing and ensures all components integrate seamlessly for large-scale power production.

By not relying on the grid for load testing, you can maintain your project schedule. You can test when you want without relying on scheduling with the utility.

Typically, you conduct solar inverter testing when your microgrid operation is complete. Load bank testing involves a combination of diesel generators and load bank devices to emulate the grid and create a simulated grid connection.

Before connecting to the grid, you must secure approval from the utility. Testing ensures the PV system and inverters do not negatively affect the utility system.

Specific Inverter Testing Functions

Load testing microgrid inverters must include these tasks:

  • Checking inverters to IEEE 1547 and UL1741 standards – You can save time and money by testing off-grid. When backfeed is available, you can reach your COD faster. Bringing your plant online by the COD helps you meet the Investment Tax Credit deadline and costly delays. Also, when you use a load bank system at the substation, you can improve safety with less load transferring and cable switching.
  • Witness testing interconnection – When you outsource interconnection system testing, you can put the Distributed Energy Resource (DER) in service sooner. Witness testing reduces the burden on utility engineering resources.
  • Performing Sleep/Wake/GPS tracking functionality for solar tracking systems – You gain a maximum return on investment of the generation system with this testing.                   
  • Conducting Combiner/Collector network testing – You can save time by testing the collection system for power factor correction before the operation goes into service. You can also save money by verifying the power factor correction systems delivers adequate power to the grid.
  • Testing voltage and frequency variations of active anti-islanding systems – When the system performs per IEEE/NEC code requirements, you can avoid risk to personnel from unintentional islanding. 

When done correctly, testing microgrid solar inverters using load banks provides many advantages. You can reduce reliance on grid availability, gain greater control over the testing schedule, ensure testing to operational specifications, and meet tax credit deadlines. Plus, solar inverter testing requires consistency, flexibility, and reliability. Unlike the grid, load banks can provide these capabilities.

Download eBook for More Information

For a more detailed discussion on load testing microgrid solar inverters, download ComRent’s latest eBook titled “Choosing a Load Bank for Microgrid Testing.” This resource will discuss the phenomenal growth of microgrids in the U.S., essential components of a microgrid, why you should load test microgrids, critical questions to answer before deploying load banks for microgrid testing, and what to look for in a load bank provider.

ComRent’s team of load bank experts helps ensure the success of your microgrid testing project. We offer a complimentary consultation to review your requirements and propose the right load bank solution for your application. Contact us online today or at 888-881-7118 for more information on load banks and microgrid testing.

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