Chattanooga, Tennessee, boasts one of America's most advanced power grids. It can self-heal and restore electricity in seconds.
The local power company, EPB of Chattanooga, spent $280 million to overhaul its electrical system with smart technology. In its first decade, the project generated $2.7 billion in economic value, according to a study commissioned by EPB. Such smart grids promise a more efficient, secure, and cleaner energy future with lower bills and fewer outages, Business Insider reports.
In most places, power starts at a large power plant. Transmission lines carry electricity from there to substations that lower the voltage and send it out on distribution lines to homes and businesses. As climate change intensifies, extreme weather events increasingly damage electrical infrastructure, causing power outages that cost American businesses an estimated $150 billion per year, according to the U.S. Department of Energy.
Meanwhile, climate solutions put their own strain on the grid. Wind and solar farms feed electricity into the system intermittently, making it difficult to match supply to the fluctuating demand for electricity throughout the day. Renewables also multiply the number of sources: From 12,000 power plants, the U.S. could need electricity from a million distributed sources like micro-hydro dams and rooftop solar panels within a few decades.
To accommodate this, the grid needs an upgrade with smart technology, said Kevin Schneider, principal engineer for power systems at the Pacific Northwest National Laboratory. A key job of any grid is to balance supply and demand. Too much electricity can overwhelm the system, while too little will leave people without power. Smart grids automate that balancing act with a network of smart meters, sensors, controllers, and computers.
EPB of Chattanooga initially needed a way for all its smart devices to talk to each other so that they could make these critical updates to their system, said David Wade, CEO of EPB of Chattanooga. Fiber was the answer. In 2008, EPB's board of directors approved the plan. With a $169 million bond, crews began digging trenches and laying fiber-optic cable throughout Hamilton County. The project was supposed to take a decade to complete, but a $111.5 million grant from the U.S. Department of Energy helped pay for an expedited timeline, cutting the completion time in half. EPB finished building its smart grid in 2012.
In just four years, EPB had installed a fiber network and connected more than 180,000 smart meters to homes and businesses. It also installed about 1,200 smart switches, which can open or close the flow of electricity on command from software or human operators from afar. These devices can quickly reroute power, closing off damaged lines to prevent outages. That means the system can self-heal and restore electricity in seconds.
As a result, EPB has recorded a 55% decrease in annual outage minutes, or 19 million minutes. Previously, utility workers had to drive to each switch and close or open it by hand. Over the next decade, EPB plans to spend another $115.5 million expanding its smart grid.
Summary
Chattanooga, Tennessee's smart grid is a model for how to prevent power outages and improve the efficiency and security of the electrical system. By using smart meters, sensors, and switches, the grid can automatically balance supply and demand, reroute power around damaged lines, and restore electricity in seconds. This technology has the potential to save businesses billions of dollars per year and make the grid more resilient to climate change.