There is a flowchart that continues to haunt me. According to the beautiful people at Lawrence Livermore National Laboratory, an estimated 38.1 quads of electricity were generated in the United States in 2012. Of those 38.1 quads of electricity, only 12.4 quads were used, and the other 25.7 quads … were, well … lost. They’re gone. They were generated, by either burning something into thick, black smoke or the elegant swooshing of windmills, and now have returned to the Universe, never having been utilized by utility company customers.
Just to put that in perspective, ONE quad of electricity is the energy equivalent to 36,000,000 metric tons of coal. That is a very large pile of coal. While some of this loss of energy is due to transmission losses as the electricity travels to users, the majority are due to power quality issues.
The topic of power quality is fairly complex, the main culprits being poor power factor, total harmonic distortion (THD), phase imbalance, and voltage variations. Since the ‘60s, inductive loads (e.g. lighting ballasts, induction motors, etc.) and non-linear loads (e.g. computers, variable frequency drives, etc.) have become much more prevalent. And due to the electronic nature of these devices, the physics of how they operate, issues related to power factor, THD, etc., have skyrocketed.
These problems range from drawing more electricity than necessary to increased heat and vibrations in equipment and wiring, causing equipment and network failure. Not only is power quality problematic to the electrical network of a facility, but the “dirty power,” as it’s sometimes called, is returned back to the grid, passing on those problems to not only other users but also utility companies. This is why for users of electricity who have poor power factor, typically <.95, excessive THD, or phase imbalance issues are charged with power quality penalties, the penalties themselves at times costing the electricity user more than their actual power bill.
When confronted with this issue, the skeptic asks, “Where is capitalism? If this issue is so costly, wouldn’t the market motivate some level of innovation so that companies can recoup their electricity losses?”
Well, capitalism came out swinging. There are a variety of devices available, known as “Power Factor Correction” or “Harmonic Filters” that compensate for power factor with capacitor banks or “filter” THD. But despite what many of these so-called “solutions” claim, they are only able to mitigate the effects. Some savings may be found, but unfortunately, a majority of these systems that can be implemented are enormous and very costly, so much so that for many companies, they are not fiscally possible to implement. What makes fixing power quality so difficult is that electricity is constantly changing at extremely high rates. The only way to be able to eliminate the “electrical contaminants,” so to speak, is to dynamically analyze the electricity and interact with it more or less simultaneously. “Real-time,” as it’s called, is a term often used when a device is able to sample at high speeds, like 120 samples a second. But even this is not quite fast enough. Given the ability of today’s supercomputers, however, these obstacles are being overcome, unbeknownst to many.
Renewable energy, on the other hand, is booming. According to the Solar Energies Industries Association, photovoltaic installations generated 7,221 MWof electricity in the US in 2012, a 76% increase from the year before. What is ignored, however, is that the process of creating solar cells, which involves the excavation and purification of silica, and manufacturing uses a lot fossil fuel energy.
Like wind mills, solar energy generation is dependent on the availability of the source (e.g. wind, direct sunlight), creating inconsistent power production. Under production causes blackouts and over production can cause the grid to be unstable, changing electrical frequencies. Beyond these issues, power quality problems persist, not to mention that the process of converting the DC to AC creates a large amount of THD, making the power quality of the generated electricity even worse. This means that there is a limit to how much power can be introduced to the grid with renewable energies before the poor power quality leads to instability and eventual grid failure. This and the high cost of solar is why there is still such a huge demand for fossil fuels like natural gas.
To me, just a single person sitting behind a desk currently in North Carolina watching winter storm Pax roll in, it makes sense, both in the short and long run, for power quality to take center stage as we combat ever increasing fuel costs and the consequences of dated technology.
Henry Maneuver is an associate with 3DFS Power Solutions, a technology company specializing in power quality.
