Tech Insights

Minimizing Safety Shutdowns With Smart Technology

June 05, 2024 by Liam Critchley

When extreme weather or natural disasters occur, de-energizing the grid becomes necessary. Smart grid technology can help.

The U.S. power grid is among the world’s most complex machine systems but is aging and contains decades-old legacy equipment. This old technology is under increasing stress from recent natural disasters, including heat waves, wildfires, and hurricanes.

Aging grid infrastructure has contributed to the spread of wildfires, which have become more prevalent and destructive in several states, including California, Oregon, Minnesota, and Hawaii. Wildfire risk is higher when the wind speeds are high but the humidity is low. In these scenarios, above-ground power lines can blow into vegetation or cause sparks, which can start fires and spread with high winds.

 

Downed power lines in a storm.

Downed power lines in a storm. Image used courtesy of Adobe Stock

 

The current approach to protecting the grid and the environment is manually shutting off the power to localized areas experiencing a disaster or fault. As natural disasters have become more destructive, public safety shutoffs have occurred in California, Oregon, and Colorado. 

Upgrading the electrical grid with smart grid technology could help to improve the grid’s ability to automatically switch off in the presence of localized faults and larger-scale disasters.

 

The Need To De-Energize and Energize Power Grids

De-energization removes energy from power lines and shuts off power to targeted areas to protect the grid and the local environment. In addition to preventing natural disasters during heat waves, de-energizing grid sections is paramount during repairs to protect workers from electrical shock or exposure to an electrical arc. When the crisis is over, re-energizing is turning the grid back on.

De-energizing and re-energizing require more thought than simply flicking an on-off switch. Due to the power grid’s complexity, striking a balance across the grid is necessary so power is always flowing in some capacity from power plants to consumers. 

Power lines cannot store electricity for later use, so the grid’s dynamics differ from many other utility infrastructures. Therefore, de-energizing and re-energizing are performed in stages. This ensures the changes are not too abrupt and the supply side can adapt. For example, power plants can’t turn on instantaneously, and each has its own switch-on dynamics. Some can take minutes, but others will take hours. It’s also not possible for any power plant to raise its generating capacity from 10% to 90% with the flick of a switch. The process takes time and is done in stages to ensure smooth power distribution under variable conditions.

Traditional power grids have many sensors in the low-voltage distribution grids—the area delivering power to local neighborhoods—and can lack specific control over individual components in these grids. At this distribution level, unplanned outages are all reported manually. However, automating the task with smart grids can digitally connect these distribution grids and the wider grid. Automation can report outages and help control the electricity flow around the grid.

Burying power lines underground is a possible solution for larger outages, such as those caused by large adverse weather events and natural disasters. However, undergrounding is cost-prohibitive, costing as much as $1 million per mile for low-voltage distribution grids and more for high-voltage transmission lines.

Smart grids can monitor and manage the electricity distribution from various generation sources to meet users' demands. Smart grid technology can help minimize interruptions and manage unplanned outages during extreme weather events. It can also help restore energy infrastructure in a storm’s aftermath to reduce the impact on human life and critical infrastructure.

 

Protecting Against Natural Disasters

Extreme weather scenarios can cause sudden power surges arising from within the grid. For example, overusing air conditioning during heatwaves or droughts can cause energy consumption spikes. Smart grids can provide better foresight to predict and prevent potential outage issues, respond flexibly, and tailor the solution based on the problem. Smart technologies use advanced data collection, processing, and analysis capabilities to streamline detection and response.

 

Smart grid management system

Smart grid management system. Image used courtesy of Department of Energy

 

Additionally, interconnectivity enables various systems to communicate, which can help restore power more quickly or divert energy from distributed energy resources (DERs) to areas needing power when other regions are de-energized. Advanced IoT sensors and monitoring systems enable the smart grid to pinpoint and analyze issues and devise solutions.

Overall, smart energy distribution allows for self-healing to restore energy after a fault without human intervention. 

Sensors and monitoring devices are smart grids’ cornerstones. Smart sensors are integrated throughout the network to monitor the grid’s operation and relay the information to the decentralized network. Network sensors autonomously capture temperature, humidity, wind speed, and power flow data in real time, enabling the smart grid to anticipate and respond to weather events.

Smart grids can also use advanced weather forecasting algorithms to predict serious weather events. Preventative planning enables the grid to automatically adjust its operations after potential events. The sensor data collected is crucial to all smart grid aspects and provides the control systems with enough data to re-route power, prioritize critical infrastructure, and isolate or de-energize any damaged sections within the network after a weather event.

 

Renewable Energy Generation and Storage

Renewable energy sources have become critical DERs within the grid and can supply power during extreme weather events. Smart grids can direct energy flow from DERs to where it is needed. Predictive analytics can anticipate fluctuations in renewable energy generation during weather events. During weather events, battery storage systems are essential for stabilizing the grid, allowing excess energy to be stored during optimal operating conditions and released to the grid when required. 

 

Essential Smart Grid Components

Efficient communication between the smart grid’s networks allows the grid to respond to outages or de-energize a grid section. Robust communication channels can facilitate seamless information exchange between grid components, so even when some grid parts are experiencing extreme weather conditions, the grid can still relay critical instructions without disruption. Smart grids with artificial intelligence (AI) algorithms enabled can also optimize the grid response by analyzing historical data to make real-time decisions to mitigate damage. Predictive modeling can provide operators with enough data to make informed emergency decisions.

Microgrids can help build smart grid resilience to adverse outages and weather events because they can be deployed when the main grid is unreliable. They can provide resources to stabilize and restore the main grid if there is an outage. Microgrids can also help restore loads to the grid by minimizing the switching operations used while maximizing the restored load.

Finally, reclosers in smart grids can interrupt loads and fault currents. Reclosers switch off multiple times in a specific sequence and can be used to re-energize the grid after a fault. Reclosers can protect the sections most likely to experience power outages. They can interrupt faults and re-energize the network closer to the fault location, providing a better upstream service. Modern-day reclosers have better current interrupting ratings and are installed closer to substations.

 

Reclosers on utility pole.

Reclosers on utility pole. Image used courtesy of Wikimedia Commons

 

Smart grid reclosers are also equipped with sensors for voltage and current and two-way communications between the device and the controller. Taking voltage and current measurements provides greater protection as they allow for fault and load monitoring. Two-way communication enables remote command transmission, which provides regular status reporting and the transmission of events to the operator. 

 

Versatile Solutions Provide Versatile Planning

Integrating smart grid technology offers numerous solutions for monitoring and protecting against outages. It can also help switch off localized grids when problems occur and turn them back on when it’s safe. A more autonomous, decentralized, and robust system can monitor larger parts of the grid and help prevent weather-caused natural disasters from starting and spreading.