Whenever a natural disaster hits, the electric grid is often damaged, disrupting the ability of the grid to deliver energy. Climate change has exasperated the frequency of natural disasters; as a result, power grid reliability is no longer enough. The electric grid must become more resilient to disaster. Here, we cover some strategies and technologies to make the electric grid resilient.
The difference between reliability and resilience:
Power grid reliability is the ability to meet customers’ energy demands both quantitatively and qualitatively. Reliability measures the ability of the electric grid to supply electricity with little to no interruption in accordance with interruption indexes proposed by the Institute of Electrical and Electronic Engineers (IEEE) Standard 1366. Energy must be delivered constantly and without interruption for the grid to be considered reliable.
Electric grid resilience, on the other hand, is the system’s ability to recover and function quickly following a disruption. Figure 1 shows the relationship between reliability and resilience, with reliability being a function of time which is no longer enough, due to increased disruptions caused by climate change and/or cyber-attacks.
Technologies currently available to improve electric grid resilience:
Several solutions are currently available to improve electric grid resilience. For example, renewable energy sources like wind turbines and/or solar farms are paired up with a lithium-ion battery bank to store energy generated to be stored for later use.
Utilities are increasingly relying on such energy storage solutions to increase resilience. There are at least ten battery storage systems paired with renewable energy generators that went live in 2021, namely; Moss Landing, Saticoy, Top Gun, Blythe Solar II, Agua Fria, Wilmot, Bat Cave, North Fork, Gambit, and Manatee.
To facilitate the increase of renewable energy use and elevate reliance on batteries as energy storage, legislations such as ‘H.4515: An Act Advancing Offshore Wind and Clean Energy’ are being passed in Massachusetts. Connecticut and Maine are also passing legislation with specific goals of increasing energy storage with Connecticut setting a 1000 MW and Maine 400 MW by the year 2030.
Storage systems reduce energy costs by using stored energy as backups during peak hours when energy costs the most. According to a study by the Ernest Orlando Lawrence Berkley National Laboratory comparing the amount of energy saved between PV and battery systems and PV alone, the combination of PV and battery systems reduces demand charges by 42% compared to 8% by PV alone.
Over 90% of all new storage capacity has been created since 2017. Based on a recent report by Wood Mackenzie, global cumulative lithium-ion battery capacity could increase more than 5x between 2021 and 2030, growing to 5,500 GWh.
Another current technique to improve grid resilience is using advanced metering and smart devices. This involves two-way communication between utilities and consumers. Two-way communication makes it easier to improve grid activities and operations, prevent outages and provide energy management services. The advanced metering infrastructure provides several key functions.
Smart meters work by keeping track of the amount and duration of electricity use. The information collected is then sent to the utility office, and the meter tracks energy flow to and from consumers with solar PV. State and local regulations have increased the usage of smart meters, which are now installed in more than 60 million American homes and businesses.
New technologies in development:
Sandia National Laboratory is developing technologies with the Harmonized Automatic Relay Mitigation of Nefarious Intentional Events Special Protection Scheme (HARMONIE-SPS), including an advanced automated grid protection system. This technology will be able to identify system conditions, mitigate cyber-physical consequences, and preserve operations during both anticipated and unforeseen disturbances. The HARMONIE-SPS will bolster grid resilience using diverse data and a machine-learning algorithm that can produce automated responses.
Packetized energy delivery is another solution in development that prioritizes load and boosts power density. This technology uses an asynchronous broadband power and communication system instead of constrained AC or DC voltage, a fixed scheduled delivery scheme (FSDS), and a flexible time delivery scheme (FTDS).
With the FSDS, the grid operator can specify the daily size and the delivery time of each packet, and the operator’s decision is made based on optimization to minimize a cost function within the limits of the system. With the FTDS, on the other hand, the customer can request an immediate delivery of energy packets (see Figure 4). The on-demand energy delivery can be implemented using explicit routing schemes developed for Internet traffic engineering.
Virtual Power Plant (VPP) is another development technology that could improve grid resilience. VPP is a cluster of microgenerators, renewable energy sources, cogenerators, or other energy sources connected to a control system that receives consumer input on the energy demand.
Varying demands between the day and night can force utilities to either build extra generators or buy more energy from other utility companies. VPPs could address this fluctuation by promptly sending more energy where it is most needed, with one central control system controlling the flow of energy accordingly. Responses are automated through distributed energy resources (DER), which tap into renewable (e.g. rooftop solar PV) and battery backup power systems to distribute power independently to different areas as required.
Some utilities and corporations such as Green Mountain Power (GMP) in Vermont and SunPower have announced their plans to launch their own VPPs. GMP has already launched its VPPs in 2022 and SunPower has also launched its VPPs at the end of 2021. The GE (General Electric) pilot program for Puerto Rico to increase resilience is also another example of VPP being developed in 2022.
Upcoming initiatives and projects to improve electric grid resilience:
To address the increase in power disruptions caused by the increase in natural disasters brought about by climate change, the Biden Administration has announced USD 13B grant meant to modernize and improve electric grid resilience in the United States. The grant will likely be open to submissions until February 2023, giving the perfect opportunity to implement improvements and upgrades, especially in more vulnerable areas.
GE is one of the larger corporations taking advantage of this opportunity. the company is launching its pilot project to make the Puerto Rico grid more resilient and prevent longer outages that could be caused by future natural disasters. The project involves using a combination of the mentioned technologies such as battery systems paired with renewable energy generators and advanced metering, and an automated power restoration system that would allow power to be restored sooner after the grid is down due to a natural disaster.
The automated power restoration system would rely on sensors that collect outage data soon after a natural disaster occurs. The system can determine the best course of action to restore power based on the collected data.
Conclusion:
In summary, it has become evident in the 21st century that the electric grid needs to be reliable and resilient in the face of climate-change-driven natural disasters and cyber-attacks. Resilience is the ability to bounce back to operation soon after a disruption. Some of the most important technologies currently in use include improved metering with smart devices, renewable energy—primarily solar and wind energy—paired with lithium-ion as energy storage, and renewable energy. Other technologies currently being explored to increase grid resilience further include VPPs and “HARMONIE-SPS.”
