I’ve written about the way this works (or doesn’t!) in a previous post. It’s about chaos, which isn’t really chaotic at all. It may have gotten that moniker as a way to deal with systems that can fly away from where you thought they were headed. It’s about natural and man-made systems with trajectories that can catapult to a very different place.
Here in the Western U.S., and across the country, there are calls for a greatly expanded network of high-voltage power lines. Those plans carry significant environmental and ecological costs. The threat from fire alone can quickly rework plant communities and just as quickly eliminate human ones. Soil erosion, damage to watersheds and water-tables, and the loss of wildlife habitat are all included in those costs.
We’re likely talking cart before the horse or, in this case, anticipating a push from the top-down before we have any feeling for pull from the bottom-up. The rapid proliferation of distributed energy sources – residential solar installations feeding into battery storage including the batteries in electric vehicles – is starting to give us just that feeling. Those emerging resources are being integrated into the electric ecosystem using digital controls, something new under the sun for the grid. Smart meters and smart inverters can use that digital intelligence in real time. That brings demand management into play so that utilities can partner with their customers to save energy on an as needed basis.
But that’s not where many utilities are headed. The legacy of rural electrification gave many a guaranteed fee they could tack onto the cost of infrastructure and the financing. All of that goes onto their customers’ electric bills – your electric bills. The big players in that arena have been at the forefront of calls for more power lines, big power lines. They will get much more money for that multi-billion dollar infrastructure than a digital build-out of the local and regional transmission grids to tap the emergence of distributed energy resources. They’ve been incentivized to chase those big dollars for more than eighty years, a business model that remains largely unchanged.
But high-voltage power lines are where the chaotic rubber hits the road. In contrast to DC power lines, AC lines are prone to failure and they will remain so. They are best described as non-linear dynamical systems. Any instability can result in blackouts. The larger the system, the more likely those are to occur.
That behavior informs many ecological systems, and the power grid is just such an ecosystem. In my time with the U.S. Forest Service, we used non-linear descriptions to model population dynamics which are also unpredictable. It was understood that without complete knowledge about the state of the system at a precisely defined time (an impossibility), any instability means the trajectory can’t be predicted. Fast-acting controls can help mitigate the resulting fluctuations, but only within well-defined limits. Push past those, and transitions to different states (including complete failure) are the rule.
The world of engineering has recently started to wrestle with this difficult fact. The seminal research only dates to 1982, when it was found that the swing equations used by power system modelers were analogous to those used in the analysis of planetary dynamics. The original work on such systems was initiated by the great French mathematician, Henri Poincaré in the late 1800s. He won an international prize competition by telling the world that solving the equations for gravitational attraction between three planetary objects didn’t have a single solution, and that some of them were beyond calculation. That was a breakthrough that led to a very different way of thinking about systems with feedback.
An AC power grid is just such a system. In a nutshell: even a simple 3-generator system was shown to transition from stable to unstable:
…in response to simulated faults on the line: tweak the operating parameters of the large generator just slightly, and a previously stable grid would run away…
This reality precisely describes the disastrous turn of events in Texas brought on by the cold spell and snowfall of February, 2021. As uninsulated nuclear plants, gas plants, pipelines, and to a lesser extent wind turbines randomly failed, the resulting instabilities pulsed through the Texas grid managed by Electric Reliability Council of Texas. Power would be restored at various intervals and at different locations, only to fail a short time later. The grid was so unstable that it came perilously close to catastrophic collapse. That’s the really important takeaway from the rolling loss of power sources during the blackout, yet it’s barely made the news.
The idea of the electric grid as a non-linear system subject to such behavior has started to take root. A detailed examination of the implications for grid planning was published in Spectrum, the journal of the IEEE, in 2004.
This missive has been met with the same sort of resistance other disciplines have faced when informed that their equations are too sensitive to initial conditions to be absolutely predictive. The answer as mentioned above is emerging and picking up speed though it’s going to take a bit of effort: rework local and regional grids with distributed generation and digital control surfaces to make the grid more stable. Doing that will allow portions of the grid to quickly disconnect themselves when disruptions happen, as they will.
Australia is moving there very quickly, and the U.S. Department of Energy’s National Renewable Energy Lab has validated that distributed generation can be used to re-energize the grid piece by piece. At the heart of this approach is a model more akin to the bottom-up Internet than top-down control of all the emerging sources. That makes little sense once tens of thousands of such sources are producing and storing electric energy.
We can grow our own and bring utilities to the table as partners, those who are willing to change those obsolete business models. I believe that’s what should happen for the good of all those ecosystems, including the human ones!
ERCOT as it’s known, does not seem to give reliable counsel. Their preferred business model of unregulated laissez-faire economics has been disastrous. They are now being sued by the largest co-op in Texas. In its bankruptcy proceeding, Brazos Electric claims that the disastrous fluctuations in the power grid resulted in per-megawatt charges that went stratospheric during the brutal cold period.