The U.S. is experiencing a boom in solar farms. During 2016, analysts estimated operators installed 14 gigawatts of solar panels, and 70% of these installations were utility-scale solar farms. This level of production provides enough solar energy to power 2.3 million homes and equals 14 large natural gas or coal plants.
In 2007, no utility-scale solar power plants existed in the U.S. By 2016, the number rose substantially with the Solar Energy Industries Association (SEIA) counting 2,100 solar PV projects over one megawatt. Solar Star near Rosamond, California is the world’s largest solar farm in terms of installed capacity. This 579-megawatt installation uses 1.7 million solar panels.
In addition to cutting carbon pollution, solar power contributes to economic growth and job creation. In 2016, the solar industry created jobs 12 times faster than the overall U.S. economy.
Although economic incentives and green initiatives drive this growth, government regulations also play a role. For example, North Carolina will require utilities to pull 12.5% of their power from renewable sources by 2021.
How a Solar Farm Works
Solar farms use solar photovoltaic (PV) panels to generate electricity that often feeds into the power grid. Typically built on the ground in remote locations, these large-scale operations can cover between one to 100 acres. Solar farms incorporate thousands or even millions of solar panels to deliver energy that powers residential and commercial buildings.
The solar panels within the solar farm convert sunlight into electricity. In more technical terms, the solar panel generates a flow of electricity by allowing photons, or particles of light, to knock electrons free from atoms in the semiconductor material. These electrons are captured in the form of an electric current.
Why Conduct Solar Farm Testing
Owners and developers that build utility scale solar farms must meet certain critical deadlines related to renewable tax credits, construction milestones, or PPA agreements. An important step in completing the commissioning requires a grid connection to energize the new facility to test all equipment and systems. But for many large facilities, the grid connection isn’t available when the testing phase needs to begin.
Even small delays can result in large financial losses from missed deadlines. The alternative is providing an alternative source of power to energize the system as an “island” and conduct testing without impacting the project schedule. A custom engineered system of generation and load banks enables full system testing even when the grid isn’t available. This protects investments, maintains public confidence in solar energy, and helps economic viability of the renewable energy market.
Commissioning of a solar farm typically involves:
- Verifying a complete installation
- Validating all components work together, especially inverters
- Ensuring safe operation
- Demonstrating compliance with applicable standards and regulations
- Documenting system performance
- Establishing performance benchmarks
- Reducing the likelihood of future outages
Advantages of Solar Farm Testing with Load Banks
A load bank is used to commission the electromechanical systems of high-performance operations like solar farms. These devices develop an electric load, apply that load to an electrical power source, and convert the power output of the source.
Load banks enable inverters to demonstrate operational performance without exporting power to the grid or customer facility. By providing a fully controlled load, load banks allow solar farms to safely and accurately measure the functionality of the complex equipment and systems within the facility.
Load banks allow you to test your solar farm without the power grid or even sunshine. Working with an experienced load bank provider, you can execute successful solar inverter testing with load banks. By emulating the power grid, load bank testing allows solar farm operators to:
- Commission installations in remote locations without power availability
- Reduce the reliance on grid availability
- Identify issues with design, installation, and system components before the operation goes live
- Avoid surprises and resolve problems before utility interconnection
- Protect investments by avoiding project delays, damaged equipment, safety incidents, lost productivity, and decreased revenue
- Offer more control over the commissioning and solar inverter testing process
- Eliminate risks of grid outages during testing
- Receive a constant and controllable load
- Save valuable time so that you can begin generating revenue as quickly as possible
- Avoid penalties from missing contractual obligations
- Meet federal and state deadlines to qualify for tax credits
- Ensure complete testing of solar PV power plants and performance to operational specifications
How to Perform Solar Inverter Testing with Load Banks
Commissioning your solar PV power plant systems involves:
- Providing a steady power source on the utility side of the PV inverters
- Energizing the entire site so available staff can work on different inverter pads simultaneously
- Connecting the power source at the main breaker of the substations
- Simulating utility power to activate the internal circuits of the inverters
- Producing power from the solar arrays and syncing them with the power source
- Providing an easily transportable generator system rated at 120% of the inverter size
- Using two paralleled generators to deter frequency variation caused by load reduction and application
- Testing medium voltage cables buried underground from the substation to the inverter pads
- Compensating for any capacitive-reactive energy created by buried cable runs with an appropriately rated inductive load bank
- Testing tracking systems to ensure the solar system tracks correctly to the sun
- Verifying array sleep and wake modes to confirm system total functionality
Simulating the grid using load banks ensures the most complete solar inverter testing and commissioning. When utility power becomes available, the solar farm can go live with the least amount of work.
ComRent’s team of experts helps ensure the success of your solar panel testing project. With zero failures on hundreds of tests, our equipment delivers the variable, sustained loads required to meet the strenuous 600+ hours of testing mandated by solar PV power plants. In fact, we provide the only combined load bank and generator solution for solar farm commissioning. Also, ComRent’s resistive and reactive solutions are the only load bank fleet in the U.S. engineered for solar PV power plants.