Ensuring Energy Security: The Role of Smart-Grid in Climate-Change Adaptation
Written by Soham Ghosh
In the last few years, a record number of severe weather events have considerably strained the electric grid and have caused some widespread blackouts, greatly endangering life and property. The integrity of the electrical grid is being challenged by climate-induced wildfires, massive unconventional winter freezes, and tropical hurricanes of ever-increasing frequency and ferocity. In this article, I present a summary of the formidable smart grid technologies such as adaptive reclosing of distribution feeders, distribution automation, microgrid systems, grid-interactive UPSes, rapidly deployable mobile control enclosures, and drone-based detection of wildfires at their onset using convolutional neural networks. These evolving grid technologies would allow us to harden the existing grid and take better control of the adverse effects of climate-change.
Historical weather patterns for rainfall and snowfall have shown considerable change in recent years in terms of its intensity, size, and duration. Prolonged droughts and higher than average summer temperatures have weakened vast forested areas rendering them vulnerable to human-induced wildfires. Recent events include the infamous Tubbs fire of 2017 in the state of California that culminated in an approximate economic loss of $1.2 billion, the Texas big freeze event of February 2021 causing estimated damage of over $130 billion, and hurricane Ida from August 2021 resulting in storm damages totaling about $95 billion. Major electrical utilities are responding to these challenges by investing in sophisticated smart grid technologies as they adapt to cope with the threats of emerging climate-change.
High Impedance Fault Detection and Automatic Reclose Adjustments
Vegetation contact contributes to the root cause of more than half of the wildfire events. The trend is being accelerated with increasingly severe droughts and human development in wildlife-urban fringe areas. Advanced reclosure technology with the ability to quickly sense high impedance faults and better tackle the potential wildfire situation is being widely explored. Relaying and protection algorithms are under development with an aim to detect and clear the fault in less than twenty milliseconds before it transforms into a formidable arc capable of igniting a wildfire.
To this effect, a growing number of utilities are relying on fault transmitters and receivers that are capable of continuously monitoring feeders in high-risk fire areas and could help dynamically adjust the protective relays trip and reclosing in real-time. These rapidly deployable fault transmitters and receivers are proven to be much sophisticated than traditional fuse based systems. The field transmitters/ receivers can wirelessly communicate fault current information to a reclosure control relay in a matter of a few milliseconds from fault inception, thereby greatly reducing the chances of a benign fault transforming into a ravaging wildfire.
Trends in Distribution Automation
With investments in sensor, processor, and communication networks forming the backbone of distribution automation systems, utilities can better manage their carbon footprint and support their post-storm response. Smart meters are at the forefront of distribution automation tools with utilities using them to:
- Better track consumer’s usage through net metering when they participate in distributed renewable energy programs
- Adjust HVAC system depending on occupancy levels in large buildings such as office spaces to shave peak load
- Monitor the extent of outages (especially multiple outages) and prioritize restoration depending on the nature of the load as read from the smart meter tag
The Definitive Role of Microgrids
Microgrid technology is likely to play a definitive role as our power grid evolves to adapt to the challenges of climate-change. Distributed energy storage system (DESS) based microgrids can:
- Support small, islanded operations in the event of a utility's transmission outage
- Promote a utility’s renewable commitments
- Be used as a black start resource in extreme scenarios
In discussions of how a microgrid can help a local community survive a major outage, the microgrid at California’s Blue Lake Rancheria (BLR) is often cited. The BLR microgrid project composed of 420 kW of solar PV arrays and a 950 kWh battery energy storage system  improved the resiliency of the BLR tribal area. In October 2017, the facilities being served by this microgrid survived and remained online after a major fire caused a massive grid outage. It should however be noted that potential risks exist with energy storage systems from a fire and safety standpoint and installations should comply with local or national codes such as the NFPA 855: Standard for the installation of stationary energy storage systems.
Data-Center UPSes Are on Our Side
Significant investments are being made in building new data centers. These data centers are safeguarded against power outages using Uninterruptible Power Supply (UPS) systems. A major drive has recently been experienced in equipping these data centers with smart-grid ready UPSes which can readily support grid imbalances due to fluctuation of renewable resources instead of having the batteries simply floating idly. Data-center UPSes can be further networked to form a microgrid with other dispersed energy resources.
Mobile Substation Control Enclosure
As a part of an industry wide effort to improve the resiliency of the electrical transmission and distribution networks, a growing number of utilities are considering having a set of rapidly deployable mobile control enclosures. These mobile control enclosures are expected to be deployed as a disaster response in case the main substation control enclosure is damaged by fire or flood. The design of the mobile control enclosure often involves a standard set of panels with microprocessor relays for protection of major substation equipment and marshaling cabinets for wiring the cables from the yard.
In the future, with the large-scale adaptation of the IEC 61850 substation automation standard and reduction in the number of yard cables, interfacing the merging units’ outputs is expected to be simplified.
Advances in Drone Technology
Drone based post storm survey and early detection of wildfires are two areas where tremendous potential exists. Post storm survey images can help utilities assess damage to their resources in a very short period and plan restorative actions.
On the other hand, early detection of wildfires is often the key to effective containment. Drones with onboard computing hardware may employ image processing and convolutional neural networks (CNN) trained to pick up small pit fires which are oftentimes the origin of larger wildfires. With advances in computer vision, several sophisticated state-of-the-art CNNs architectures exist, but often simple separable CNN architectures such as the one proposed in  yields sufficiently high sensitivity and are computationally less expensive. From an operations standpoint, early detection of wildfires can often allow system operators to reconfigure the grid topology, thereby allowing uninterrupted service to the majority of its users.
With record-setting climate events threatening public safety and general infrastructure, there is a huge driving force towards a more resilient energy grid. The smart grid technologies of today, as discussed in this paper, will continue to evolve with utilities and government institutions investing in their research and development in response to climate induced grid events.
- California Energy Commission, "Demonstrating a Secure Reliable Low-Carbon Community Microgrid at Blue Lake Rancheria," 01 2019. [Online]. Available: https://www.energy.ca.gov/sites/default/files/2021-05/CEC-500-2019-011.pdf. [Accessed 09 2021].
- S. Dutta and S. Ghosh, "Forest Fire Detection Using Combined Architecture of Separable Convolution and Image Processing," in 2021 1st International Conference on Artificial Intelligence and Data Analytics (CAIDA), Riyadh, Saudia Arabia, 2021.
This article edited by Ali Nabavi