Home → Blog → Energy concepts → Intro to Power Quality: the Overlooked Challenge of the Energy Transition
By
Withthegrid Team
Published on:
06/11/2024
As the world races toward an electrical and sustainable energy future, there’s a critical piece of the puzzle that most of us have been missing. While solar panels, wind turbines, and battery storage tend to dominate the conversation, Power Quality remains unnoticed. But why does it matter?
The following might happen to you: you’re at home, plugging in your electric vehicle for tomorrow’s commute when, suddenly, the lights flicker, your smart thermostat reboots, and your EV charging slows to a frustrating trickle. These aren’t just minor disruptions – it’s a snapshot of what could happen to entire energy grids if we ignore the role of power quality in the energy transition.
Power quality, also defined as the reliability and stability of our electrical supply, is a fundamental requirement for the success of renewable energy integration. Ignoring it could cost us a lot down the line. Think of damaged infrastructure and electrical equipment, lost renewable energy production, and an unreliable energy system. So why isn’t this issue getting more attention? The truth is, we don’t see many of the problems described above – yet! Additionally, power quality can seem complex, technical, and perhaps, not as captivating as solar panels or wind farms. Yet, at Withthegrid, we recognize its essential role and aim to bring clarity to this topic.
📌 Withthegrid expert Pieter Hogeveen in collaboration with Henry Lootens gave an interview in Solar Magazine about Power Quality issues in the Netherlands. Interested? Read the article here: Spanningskwaliteit – een vergeten factor in de energietransitie?
I. Understanding Power Quality
What exactly is Power Quality?
Power quality describes the degree to which the electrical power supply matches ideal specifications for optimal and efficient equipment performance.
It involves key factors such as voltage, frequency, and waveform consistency – elements that impact everything from household appliances to industrial equipment.
What happens when these factors deviate? The consequences range from flickering lights to productivity loss, damaged equipment, disrupted operations, higher maintenance costs, network failure and in some cases, (public) safety risks. That’s why maintaining high power quality standards is essential, especially as more industries and technologies depend on uninterrupted electricity.
Standards in Power Quality
In the Netherlands, for example, residential voltage standards on the low-voltage grid specify 230 volts at a frequency of 50 Hertz, allowing for a 10% deviation (207 to 253 volts). Stray outside this range, and your appliances – everything from washing machines to laptops – become prone to inefficiency and damage.
In medium-voltage grids, where voltage reaches up to 25,000 volts, these quality parameters are equally critical. Standards established by the Electricity Network Code and NEN-EN 50160, regulated by the Netherlands Authority for Consumers & Markets (ACM), define these quality thresholds.
II. Causes and consequences of poor Power Quality factors
Common poor power quality problems
Poor power quality can arise from a variety of factors, which often relate to either the supply system or the loads on the system. Understanding these indicators can help professionals identify issues within power systems and inform strategies for mitigating their impact.
Voltage variations:
Voltage variations include dips/sags or swells/surges, where the line voltage temporarily rises or falls above or below the nominal voltage. Causes can include network faults, switching of capacitive loads, or excessive loading. These fluctuations can disrupt operations and shorten equipment life.
Interruptions/Outages:
Interruptions refer to a complete loss of power (voltage falls to zero), lasting from a few seconds up to several hours. The consequence is quite straightforward: all equipment stops working (for example).
Transients:
Transients, also known as voltage spikes, are brief yet extreme increases in voltage, typically lasting only microseconds. Common causes include lightning strikes, switching capacitors, and turning large loads on or off. Transients can pose a risk to sensitive equipment due to their high magnitude and rapid onset – it can lead to the destruction of components (particularly electronic ones) and of insulation materials.
Harmonics:
Harmonics are unwanted frequencies that are integer multiples of the system’s fundamental frequency. In other words, they are higher-frequencies that distort the normal electrical waveform. Harmonics can lead to issues like equipment overheating and a reduced power factor (see below), which impacts overall efficiency. Harmonics are often introduced by non-linear loads like variable frequency drives, electronic devices, and LED lighting.
Voltage unbalance:
Voltage unbalance is an issue in three-phase power systems where the voltage magnitudes differ across the three phases, resulting in an asymmetrical waveform. Unbalance can reduce the efficiency of motors and other three-phase equipment.
Flicker:
Flicker, primarily affecting lighting, is characterized by systematic variations or random changes in the voltage waveform, leading to noticeable fluctuations in light intensity. This can be disruptive in environments where stable lighting is essential.
Frequency variations:
Frequency variations are simply deviations from the standard supply frequency (50 or 60 Hz). More common in weak power systems, it can disrupt the operation of equipment that relies on precise timing. Sensitive systems, such as clocks, certain motor drives, and communication equipment, may experience errors or even fail to operate correctly
Noise:
Electrical noise, taking commonly the form of electromagnetic interference (EMI) or radio frequency interference (RFI), can negatively impact electronic equipment and communication systems. This interference can disrupt signals, resulting in data errors and reduced performance.
Power Factor issues:
Power factor represents the relationship between apparent power (measured in kVA) and active power (measured in kW) in an electrical system. It measures how efficiently electrical power is converted into useful work (active power). A low power factor indicates that the system uses more apparent power than active power, signaling inefficiencies and leading to wasted energy.
Power Quality challenges in the Netherlands
Fluctuations in Power Quality level are often tied to variations in sustainable energy generation, shifts in demand or badly designed and operated equipment. With the increasing integration of renewable energy sources and rise of electrification, we can see that power quality issues are becoming more common.
Power Quality in a carbon-free system
Shifting to a carbon-free electricity system involves changing how energy flows across the grid. As we move from centralized power plants to decentralized sources like solar panels, EVs, and wind farms, there are increased variability and direction changes in energy flows across voltage levels. Parts of the network are now at risk of overloading, which means that grid reinforcement and operational adjustments are no longer optional.
At the same time, our homes and businesses are filling up with electronic devices that complicate the predictions of electrical system behavior. Many devices introduce “harmonic pollution,” which can strain systems and reduce reliability. Adding the growing load from electric vehicles (EVs) and batteries, we’re reaching a tipping point.
The challenge is now to integrate all these new technologies while maintaining voltage quality standards and minimize costs for both consumers and grid operators.
Recently in the news
In the Netherlands, Power Quality issues particularly arise in areas with extensive decentralized solar energy generation. A recent report by Netbeheer Nederland (2023) highlighted several incidents illustrating these issues:
- For instance, in Zevenbergen, a household connection recorded a total harmonic distortion (THD) level slightly above the accepted 8% threshold, reaching 8.04%.
- In Bleiswijk, a rapid voltage variation was recorded, contributing to noticeable flickering in lighting systems.
- Additionally, slow voltage variations have been reported in locations such as Schoonebeek, Bargermeer, and Coevorden. In these cases, the issue stems from decentralized generation leading to a low-loaded network, particularly at sunrise and sunset, when network voltage spikes occur.
These examples highlight that the grid is already encountering power quality deviations, which challenge the reliability of our electricity supply.
III. How to address Power Quality issues? It starts with monitoring
To maintain a reliable power supply, continuous monitoring and intervention are key. Tools like Power Quality Monitoring (PQM) systems provide insights into system performance, helping identify potential disruptions before they cause serious issues and anticipating maintenance.
However, many conventional PQM systems only measure based on 10-minute averages for a period of 7 days to meet EN 50160 standards.
This approach overlooks short-term voltage peaks that can cause significant issues, such as the shutdown of solar panels due to excessive voltage in areas with high levels of decentralized generation. Similarly, undetected peaks in harmonic distortions can lead to gradual damage to equipment and network components, such as transformers.
Without timely identification, these distortions may lead to large-scale network failures as the energy transition progresses and the grid faces increasing demand and strain.
Withthegrid’s Asset Monitoring Platform fills these gaps by providing near real-time data on power quality metrics. Using IoT-connected devices, it continuously tracks key metrics including voltage fluctuations and harmonic distortion, providing immediate alerts on anomalies that may otherwise go unnoticed.
This proactive monitoring helps prevent issues, such as transformer damage and equipment shutdowns, supporting grid stability and extending asset lifespan – especially important as demand increases. Learn more here.
Conclusion
Power quality is a foundational, though often overlooked, component of the energy transition’s success. Without stable, reliable voltage, the potential of renewable energy sources, electric vehicles, and smart grids cannot be fully realized.
Engie Laborelec advocates for a significant expansion in monitoring capacity, which involves installing more smart meters at strategic locations and implementing real-time monitoring to better manage the dynamic changes within the grid. This is particularly critical in regions with high levels of decentralized generation and frequent fluctuations.
Following recent recommendations, increased weekly or continuous measurements in renewable-energy-heavy areas (with for instance, a lot of PV, heat pumps or EVs) would allow grid operators to detect and address potential issues earlier. To support these improvements, the Netherlands Authority for Consumers & Markets (ACM) is preparing a market consultation to explore advancements in power quality.
Implementing enhanced, more frequent monitoring is essential for addressing both current and future voltage quality challenges. Only through these measures can we secure a resilient and sustainable energy infrastructure that supports our transition to a cleaner, more efficient energy future.
Have a question? We’re here to help!
Power Quality may be a behind-the-scenes topic, but it’s the backbone of a reliable energy system. Reach out, and let’s talk about how we can help you monitor your grid and transformers for Power Quality issues.