When the electric grid was created more than a century ago, it was intended to deliver power one way. At that time, no one could have imagined the technological advances resulting in the bidirectional flow of power entering the grid from many points. The intermittency of renewables combined with the influx of residential solar, microgrids, EV charging stations, energy storage systems and other distributed energy resources (DERs) are wreaking havoc on an electric grid that was not designed for this purpose.
As the race to net zero continues, utilities are pursuing renewable energy options despite the limitations of our current infrastructure. Of the more than 100 utilities participating in our 2021 survey about renewable integration conducted by Micatu and ZPryme, 90% told us they would integrate renewables over the next five years. Nearly half of the respondents have already integrated them.
While the debate rages on about what the future grid will look like, for now, electric grid operators need to manage renewable integration with the grid they have today. And that means measuring and monitoring factors that have not previously been a priority.
Two primary challenges with renewable integration emerged during the Micatu/ZPryme survey: power quality (65%) and backfeed (48%).
Power quality disturbances are changes in voltage, current, and frequency that interfere with the regular operation of electrical equipment. It will manifest as voltage sags, swells, flickers, harmonic distortions, power interruptions, and voltage imbalances which cause an inefficient flow of energy through systems in buildings, homes, devices, and more. Issues with power quality can lead to higher electricity bills for end users, increased emissions, a shorter lifespan for electrical devices and equipment, and increased chances for costly equipment maintenance and replacement due to breakdowns caused by overheating. It can also result in electrical fires and the overheating of electrical networks, making safety related to power quality a top concern for 77% of utilities.
The most effective way to manage power quality is to measure it and see what the data tells you. However, most utilities don’t have sensors that are sophisticated enough to monitor the data that is required to manage power quality. Legacy equipment, such as PTs and CTS, simply don’t have the capability.
DERs increase the number of points along the grid that generates backfeed, or the flow of electricity in the reverse direction of typical flow. Backfeed can sometimes be intentional, like when wind turbines or solar panels produce more power than is consumed during peak generation. But, more often, backfeed is unintended. This can result in hazards to the electrical grid and service personnel because of the transfer of large amounts of energy.
82% of utilities in the survey said they do not monitor backfeed. As with power quality, this may be primarily driven by the fact that legacy equipment cannot measure these factors.
If legacy equipment can’t provide the measurement and monitoring capabilities that electric grid operators need to manage the chaos on the current grid or monitor a modern grid, how can they maintain reliability?
Optical sensing technology is emerging as the solution to help operators ensure grid stability. Non-conductive sensors measure the electric field using light passed through a crystal to provide real-time data on voltage, current, vibration, harmonics, power quality, and temperature with an unprecedented accuracy of =/-0.5% on both current and voltage, allowing operators to monitor things on the grid that were previously invisible, such as power quality and backfeed.
An optical sensing platform also offers one of the safest ways to measure power quality on the grid today. By not passing electrons, grid operators can avoid equipment overheating and violent, explosive failures. For example, Micatu’s 69kV optical sensor has been tested and proven to withstand zero saturation damage up to 175kA.
To learn more about the benefits of the highly accurate data provided by optical sensing technology, read Micatu’s white paper, “A Grid Disrupted: How Optical Sensing Manages the Chaos with More Accurate, Digital Measurements.”
You can also access the complete Micatu/ZPryme renewable integration survey HERE.