New high-tech solutions keep power flowing more reliably than ever—along with good old common sense planning
Much of the work to keep your lights on nice and steady takes place behind the scenes, in places you can’t see. Electric utilities are continuously upgrading equipment and procedures. It’s part of their commitment to serve you around the clock, all year long.
To really understand these hidden improvements, it helps to know the difference between a “reliable” electric grid and a “resilient” grid.
A “reliable” grid is a system that consistently delivers high-quality electricity. Utilities operate different combinations of generators in their region to achieve a good match between the supply of electricity and the demand for it, providing exactly the right amount of power for all consumers. The flow of electricity is constant. Service is seldom interrupted, with very few brownouts or blackouts.
But when outages do occur, a “resilient” grid is a system that can recover quickly and easily from disruptions. Electric utilities strive for both a reliable system and a resilient system.
Planning and upgrading for reliability
Building on decades of experience, electric co-ops have devised good maintenance schedules that reduce outages due to equipment failures. For better reliability, an aging transformer might be removed and replaced a few months before the end of its expected useful life so that there’s no interruption in service. And utilities plan months in advance how to coordinate shutting down one power plant for regular maintenance, then starting up a different power plant to supply the correct amount of electricity. The transition occurs smoothly so consumers don’t notice any changes.
Co-ops have also crafted excellent emergency plans to recover from outages caused by disasters such as floods, tornadoes, or ice storms. For better resiliency, when severe weather is expected, replacement poles and coils of wire are pre-positioned where they’re likely to be needed. With these materials in handy locations it’s much quicker and easier to make repairs after the storm is over.
These are practical details, and they’re mostly based on mechanical and physical things. But what’s becoming increasingly important for both reliability and resiliency is the use of electronics throughout the power grid.
Since 2010, electric utilties in every region of the country have invested nearly $4.5 billion in advanced devices to improve the way the grid works. More than 10,000 automated capacitors (spring-like gadgets that respond to changes in the flow of electricity) have been added to distribution lines to keep the current moving steadily at the correct pace. Equipped with sensitive electronics, these capacitors don’t need a human to set them in motion.
More than 7,000 automated feeder switches have also been installed. When a problem occurs in one place, these devices can route the flow of electricity around the problem area and keep service steady without interruption. Computer technology allows these gadgets to do their work on the spot (either with or without human intervention) and report their activities to a central location.
Fancy equipment for better results
But the most remarkable power grid innovation involves mailbox-size devices that monitor the flow of electricity, gathering data up to 30 times per second. Known as “synchrophaser” technology, these gadgets and their continuous reporting allow power grid operators to “see” how electricity is moving through the system in ways that were never possible with strictly mechanical devices. So far, about 900 of these devices have been installed.
There’s very little room for error in the power grid. The movement of electrons that gives us the electricity we use in every part of our life has to meet certain standards that are measured in extremely tiny units—and things happen very fast. Synchrophaser technology gives power grid operators measurements of what’s going on in real time, often helping them spot a potential problem quickly enough to make rapid adjustments before serious interruptions occur.
Knowing about the split-second changes in the flow of electrons is becoming increasingly important as power flowing through the grid includes more electricity from solar, wind, and other renewable sources that produce electricity in variable quantities. Instant two-way communication between electronic devices and sensors strategically placed throughout the power grid will help power grid operators keep the system reliable—and keep your lights on when you need them.
How reserves keep the light on
The combination of generators that utilities use varies from season to season. Not all generators within a region produce their full amounts of electricity all the time. For example, only three out of four generators at a power plant produce electricity during mild autumn months. The amount of electricity that the fourth generator could produce is called “reserve capacity.” As temperatures get colder and demand for electricity increases during winter, these reserve generators begin operating.
During extremely cold spells, when all normal generators and all reserves are producing the most electricity possible, problems can occur if demand spikes even farther upward. During these unusual times, utilities may ask consumers to use fewer appliances, to set their thermostats lower, and take other measures so that demand does not exceed their ability to supply electricity.
The latest reliability studies and reports point out that having the right amount of reserve capacity will always be important—and certain standards must be followed. Many reports note the risk of taking certain kinds of power plants out of the generating mix to meet environmental regulations. If reserves get too low, that could make it more difficult for utilities to provide enough electricity during extremely cold or hot weather.
Nancy Grant from April 2015 Issue