Power Quality Explained & why projects fail
Harmonics, Voltage Drops & Why Renewable Projects Fail
As renewable energy systems continue to scale across the UK, one issue is becoming increasingly difficult to ignore. Power Quality.
While system design, compliance, and hardware selection often take centre stage, the quality of the electrical supply itself can have a major impact on performance, reliability, and even whether a project is approved in the first place. In many cases, power quality is the hidden factor behind underperforming systems, or failed grid connections altogether.
What is Power Quality?
Power quality refers to how stable and consistent an electrical supply is. Variations in voltage, frequency, or waveform distortion can all introduce problems, particularly in systems that rely heavily on inverters and electronic components.
Globally recognised standards such as IEEE 519 help define acceptable limits for harmonic distortion and system performance. You can explore this standard here: https://standards.ieee.org/standard/519-2014.html
These guidelines, developed by the IEEE, are widely used across the industry to maintain safe and efficient operation.
What Are Harmonics?
Harmonics are distortions in the electrical waveform, typically caused by non-linear loads such as solar inverters and battery storage systems.
While often invisible during normal operation, their impact can build over time, affecting both performance and equipment lifespan.
Common effects of harmonic distortion include:
Overheating of cables and transformers
Reduced system efficiency
Increased wear on electrical components
Unexpected system shutdowns
For a deeper technical breakdown, this article provides a useful overview:
https://powerquality.blog/2021/07/22/ieee-519-harmonic-limits/
Why Power Quality Matters More Than Ever
As more renewable systems connect to the grid, maintaining stable power quality is becoming increasingly challenging.
According to industry specialists such as Fortop UK Automation & Energy Control (https://fortop.co.uk), issues like harmonics and voltage instability are now far more common, particularly on constrained networks.
In practical terms, this means installers and developers are now encountering:
Voltage rise during periods of high export
Phase imbalance across three-phase systems
Harmonic distortion from inverter-driven loads
Transformer overloading in high-demand environments
These are no longer edge cases. They are becoming standard considerations in modern project design.
How Power Quality Impacts Project Feasibility
Power quality doesn’t just affect performance. It can directly influence whether a project is viable.
In some cases, excessive harmonic distortion or voltage issues can prevent a system from meeting DNO requirements, leading to delays, redesigns, or outright rejection. This is particularly relevant in areas where grid capacity is already under pressure.
If you’ve already read our DNO application guide, you’ll know that approval is becoming increasingly dependent on how well a system integrates with the wider network, and power quality plays a major role in that.
Common Power Quality Issues in UK Solar Projects
From real-world project experience, the most frequent issues include:
Harmonic distortion caused by inverters
Voltage rise during peak generation periods
Phase imbalance affecting system stability
Overloaded transformers in constrained networks
This type of issue list is often referenced across technical discussions and highlights just how critical early-stage planning has become.
How to Prevent Power Quality Issues
The most effective way to deal with power quality is to address it early, not after installation.
A proactive approach should include:
Conducting power quality assessments during system design
Using monitoring equipment to track performance
Designing systems with mitigation strategies in place
Implementing corrective solutions where required
By identifying potential issues early, you can avoid costly delays and ensure smoother project delivery.
How can we help you
Power quality is no longer a secondary consideration, it’s a fundamental part of delivering successful renewable energy projects.
As systems become more complex and grid constraints increase, understanding and managing power quality will only become more important.
At G59 Projects, we’re seeing these challenges first-hand and are actively developing solutions to help clients monitor, manage, and optimise power quality across their installations.
🟢 Speak to the team at G59 Projects to discuss your project and how we can support you.
