Grid codes and testing requirements: What does a power plant operating permit require?
Grid codes provide the foundation for grid code compliance of power plants. Without compliance with grid requirements, a power plant cannot obtain the final operational notice (FON) from the grid operator. Grid codes typically also require testing to ensure compliance with grid requirements before granting the operational notice. The tests evaluate, among other things:
- the power plant’s ability to operate under over- and undervoltage conditions
- the performance of various control modes
- reactive power production and consumption
- active power limitation
Testing timing and conditions: When is the optimal time to perform grid compliance tests?
The timing for verifying grid compliance is usually determined by the schedule set forth in the grid code, where the deadline for testing is tied to an earlier milestone, such as an interim operational notice (ION). According to grid requirements, some tests must be conducted at a specific threshold power level, which is tied to the power plant’s rated capacity. This dependency on weather conditions, particularly for renewable energy production, makes the testing schedule uncertain and challenging to predict. Generally, spring and autumn are ideal times to test wind power plants due to favourable wind conditions that enable high-power testing. Similarly, solar power plants are mainly tested from spring to early autumn.
Spring and autumn are excellent times to test wind farms and solar power plants.
Test planning and implementation: How to ensure a smooth testing process
It is recommended to prepare for the tests well in advance. However, the test plan must be submitted to the relevant grid operator in Finland no later than two months before the grid code compliance tests. Ampner coordinates the arrangements for the tests with other relevant parties. Grid code compliance tests are performed when the power plant is fully commissioned and operates with its final control parameter settings. Typically, the tests are completed within a single working day, but testing hybrid power plants may require multiple days due to different power plant sections. During the tests, Ampner can conduct the required measurements using own measurement equipment or coordinate with the equipment supplier if compliant meters are already installed on-site. Ampner has extensive experience conducting grid code compliance tests remotely, which is possible in Finland, for example.
Test reporting and validation: Final steps in obtaining operating permits
After the tests, the data is processed and compiled into a test report, which is submitted to the grid operator within three months. Raw data is also structured and packaged according to requirements. At this stage, the project’s compliance verification process is in its final phase, with only validation using the PSS/E simulation software remaining. During validation, the simulation model is verified against the measured test data. Once the validation report and clarifications to previously submitted documentation are provided to Fingrid, the grid operator can grant the power plant its final commissioning approval.
Our main goal is always to obtain the operating permit on schedule.
Comprehensive partnership: Expert support from Ampner – from design to commissioning
Ampner aims to provide its customers with comprehensive services related to power plant design and grid code compliance, from preliminary planning and component selection to testing, modeling, and simulations. The primary goal is always to ensure that the customer receives the final commissioning approval on time.
Steps for grid code compliance testing and verification:
- Preparation
- Ensure power plant’s technical readiness for testing
- Plan testing schedule considering weather conditions
- Prepare test plan (to be submitted 2 months before tests)
- Test implementation
- Coordinate test arrangements with all parties
- Ensure availability and suitability of measurement equipment
- Perform tests within approximately one working day. Hybrid power plant testing takes several days.
- Documentation and reporting
- Process and analyze test data
- Prepare test report (to be submitted within 3 months)
- Validate simulation model
- Securing the permit
- Submit validation report and necessary clarifications
- Ensure documentation completeness
- Obtain final operating permit
Contact our experts to ensure smooth progress in your grid code compliance verification project.
