You may think you know the ins and outs of power quality. But in dynamic industries like power engineering, electricity generation and facilities management, best practices can change rapidly. This is especially true with the rising adoption of EVs and other new technologies in electrical power distribution.
In this blog, we’ll set the record straight on three common misconceptions relevant to power quality and power grid stability. Keep reading to discern fact from fiction about power quality analysis, the future of electrical power distribution and more.
Myth #1: Power factor is an exact science.
For industrial facilities consuming a lot of power, power factor is a critical metric for improving equipment performance, properly sizing equipment, monitoring energy efficiency — and ultimately keeping energy costs under control. But there are nuances with how utilities might calculate your power factor, as well as how utilities penalize businesses like yours for a low power factor.
To avoid additional charges, you need to understand how your utility penalizes for poor power factor. Typically, penalties are assessed when the ratio of working power (kW) to apparent power (kVA) falls below certain limits.
Knowing your utility’s approach will guide how you plan to meet power factor requirements — especially since power factor can change with tiny variations in your working, reactive and apparent power.
Consider the effect of load variability: Is your average power factor low because loads are frequently idle? This was the case for one Powerside customer running a grain elevator. Based on our analysis of their data, we found it best to consistently run a 200kVAR fixed unit capacitor to cover correction from the transformer at low load, and engage auto-switching with a 600kVAR capacitor as power on the system increases.
Ultimately, the key is investing in a power factor correction system that reacts with granular accuracy, like Powerside’s various power factor solutions. Choosing the right solution requires consideration of multiple factors — like those explored in this “Power Quality Analysis” Powerside blog — so be sure to seek professional advice.
Myth #2: Increased adoption of EVs will “break the grid” unless we build a massive amount of new power generation.
The U.S. government’s commitment to install 500,000 public EV charging stations by 2030 has many concerned. The question on everyone’s mind: Will the grid be able to handle the stress?
According to the Office of Energy Efficiency & Renewable Energy, power grid stability remains reliable even with high levels of variable renewable energy. That said, many utilities are optimizing energy capacity by offering EV customers off-peak charging rates and similar time-of-use (TOU) programs that divert consumption to less congested times. PwC analysts posit that by 2040, California utilities could shift up to 41 GWhs of combined daily load to more optimal times through well-designed TOU strategies.1
Meanwhile, don’t discount the power of microgrids as a viable answer to EV charging demand. The combination of renewable energy — most notably solar — as well as onsite energy storage devices create a localized “power station” capable of supporting EV charging. Additionally, engineers continue to work on vehicle-to-grid (V2G) and grid-to-vehicle (G2V) technologies that add further capacity as temporary energy storage systems (ESS) and can compensate for microgrid resource fluctuations. An interesting study out of Jordan University of Science and Technology demonstrated that this type of scheme reduced energy drawn from the grid during working hours by 90%.2
So, while many observers worry that EV demand will exceed generation capacity, the reality is that advances in energy efficiency have led to decreased power consumption. Even as we wait for widespread deployment of ESS technologies, the U.S. power grid remains relatively robust.
However, power quality is another story.
One problem that utilities and EV charging station operators do need to be concerned with are power quality issues that arise from these modern technologies. Inverters used in the charging equipment and in renewable power generation create voltage disturbances. The good news is that these challenges are successfully addressed with ongoing power quality monitoring and mitigation solutions at the site level.
Myth #3: Advanced sensors can be relied on to collect accurate measurements for power grid stability.
Power analyzers and advanced sensors are useful instruments for collecting equipment performance data. However, their veracity can’t be assured without further investigation on a localized basis. The metric used to quantify a sensor or sensor system’s measurement performance is called conditional accuracy.
Sensors are affected by several conditional variables relative to their location, such as weather and communication networks. Conditional accuracy provides a metric on how well the sensor system can work under unique operating conditions, like:
- Local temperature fluctuations
- External electric field disturbances
- Operating measurement range
- Timing and latency issues
It’s a challenge to cover every possible factor that can impact power analyzers and the sensors feeding the data. Even so, IEEE is currently working to create technical standards for smart grid sensor systems, with the goal of encouraging manufacturers to test their sensors in labs that mimic real-world scenarios. (Powerside’s own Nick Nakamura is part of the IEEE Power & Energy Society team working on this project, so we will be sure to keep you informed on progress.)
Read more about conditional accuracy and its role with smart-grid sensors here at the Powerside blog.
Stay ahead of the rapidly changing power landscape
It’s an exciting time for the power industry, with new innovations and sustainable practices emerging every day. This also presents new challenges to maintaining power grid stability.
Make sure your business never experiences a setback due to poor quality power. Explore our power quality solutions, or contact a Powerside expert to see how we can help you improve your power quality today.
1 PwC, EV charging growth: How can power and utilities prepare?
2 Study by Ahmad AbuElrub, Fadi Hamed and Osama Saadeh, “Microgrid integrated electric vehicle charging algorithm with photovoltaic generation,” published in the Journal of Energy Storage, September 11, 2020