More on Electric Power in Stephens Valley

 

Edition 1. Issue 7.                                 June 2022

Let’s talk some more about the issues of electric power, broadband, and mobile phone service, and the reliability thereof, here in Stephens Valley. After the storm on May 21, that seems to be a very timely topic.

While we covered the general topic of how our homes receive electric power from Nashville Electric Service back in Issue 4, this electric power discussion will be more focused on our individual reliability needs.

The industry that I spent my life in is changing rapidly. The association of electric power and broadband networks produces new opportunities and capabilities. In a former life, I called the offspring of that marriage “infotricity,” and I still think that is a good name. Had this concept been pursued at the onset of Stephens Valley, it would have been a tough fight to get it implemented, but things would be a bit different in our valley. SV could have included NES’s first micro-grid. A micro-grid is a semi-autonomous segment of a larger grid, one that is capable of isolation from the main grid, and temporarily operating on its own resources. Here is how the SV micro-grid would work. At the loss of power in the NES circuit which normally feeds SV, automatic switches would isolate SV from NES and begin to provide power to SV from its distributed resources. These resources would include solar arrays and grid-battery storage. Broadband would be used to command all non-essential loads in SV homes to turn off, so that the stored energy could provide lighting, refrigeration, garage door operations, and telecommunications. The resulting reduced load profile could allow such a battery system to keep SV afloat for several hours, while no single owner would be tasked with owning and maintaining an individual system.

Of course, micro-grids are a bit more complicated than that. The developer would have to allocate some land for the solar arrays, and an arrangement would have to be created with NES to interface the grids, but the result could have been an amenity that produces benefits, both in comfort and in economics. You see, the evolving power industry could also make it possible that the power produced by the SV generation is sold to NES/TVA on all the other days when that energy is not needed by the SV residents! An amenity that the residents and the developer both have equity in could be a real asset, but it seems doubtful that such a project would interest the developer. Still, of all the options available to us for improving our electric power reliability, this would be the gold standard solution, and all of the technology to make it work already exists.

Since a community-wide solution seems unlikely and nearly impossible, there are a lot of other options available to us for protecting our own homes from extended power outages. There are tried and true solutions, like installing an individual standby generation system. While these systems work great, they are expensive and must be constantly maintained after installation. There are new options coming too. Take a look at the tsunami of new electric vehicles coming to market. These EVs will increasingly offer technology to allow the battery system in the vehicle to back feed its stored energy into the home, allowing it to function like a standby generation system when it is plugged in. The exciting thing about these is that you can also take them out and drive them! EVs are proliferating at such a rate that home builders would be very smart to go ahead and install 240-volt outlets in the garages of all new SV homes. We are all going to need them soon enough, and it is certain that the next owners of our homes will want this feature installed.

But before we go off on one of these relatively expensive solutions to electric power reliability, let’s look closely at the size of the problem we seek to solve. Since we explained the architecture of the NES grid as it relates to SV in Issue 4, we know that NES has made some significant investments in reliable delivery to SV. Although the normal feed to SV comes down a tree-infested McCrory Lane, NES has also provided a couple of redundant feeds that they can use to restore our power if those trees fall. They have also provided redundancy within SV with alternative underground cabling routes. So just exactly how likely are extended power outages in SV, and how long should be expect them to last. We’ve really got to know these givens before we choose how we are going to protect ourselves.

I’m going way out on a limb here. I am going to suggest that we ought to expect an average of five hours per year of power outages from NES. Since we all live in new, well-constructed homes, we should endure the temperature just fine, even while our HVAC is out of operation. The reasonable and low-cost steps we should all take to survive those rare outages are these:  have flashlights strategically placed and every year on the first day of spring – replace the batteries; have a battery-operated AM-FM radio and follow the annual battery replacement guideline above; buy a mobile phone backup battery/charger (around $30) and make sure it is charged up annually; and consider buying a UPS (battery) to power your WiFi router (this solution is not perfect, because even though your home WiFi router is backed up, loss of power to other components on the broadband provider’s network can still leave your router down). We also learned something about AT&T mobile phone service during the May 21 outage. It isn’t very good. Look at the option of using more than one phone service vendor for the phones in your household. Diversity and redundancy are good for essential services, and our mobile phones are certainly essential. Using these relatively inexpensive safeguards can really help you endure the brief outages SV experiences.

William Ray - Author