The Cybersecurity Value of Microgrid Islanding

This is the third article in a Microgrid Knowledge series that explores why we need to focus on microgrid cybersecurity and the value of microgrid islanding. 

cyber grid attack

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The value of microgrids as a cybersecurity defensive measure begins with their unique ability to operate in two different modes: connected to the electric grid or islanded from it as a self-contained system and independent power provider.

In most instances, a microgrid operates in grid-connected mode and its assets contribute to the strength of the overall grid. But if a fault in the utility grid causes a loss of power, a microgrid can disconnect from the grid and independently serve its customers via its on-site generation resources. This islanding ability makes microgrids very attractive for critical operations, such as emergency first responders, military operations, hospitals, airports, and water treatment facilities.

Microgrid islanding would come into play if cyber terrorists crippled the electric grid and caused a major power failure. Sensing the disruption, software technology would isolate the microgrid’s local generation sources and loads from the trouble. Those local power sources within the microgrid’s footprint would activate and supply electricity to the microgrid’s customers. Often these power sources are some combination of renewable energy, batteries, combined heat and power, or emergency generators.

Microgrid islanding would come into play if cyber terrorists crippled the electric grid causing major power failure. Click To Tweet

We have no examples of microgrid islanding occurring in North America during a cyberattack because – fortunately – the grid has never been crippled by a hack. But microgrids have demonstrated the value of islanding during other major calamities.

Microgrid islanding during Superstorm Sandy

For example, in 2012 when Superstorm Sandy came ashore in New Jersey and ripped up the East Coast, eight million electric customers lost power, but the lights stayed on at Princeton University because the school’s microgrid islanded.

The microgrid operated until power was restored to the main grid – a day and a half later – providing necessary electric power and heating needs. Because of the microgrid, Princeton became a refuge where police, firefighters, paramedics, and other emergency services workers could charge phones and equipment. Local residents were also invited to warm up, recharge phones and use the wireless Internet service at a hospitality center the university made available.

It’s not only hurricanes and cyberattacks that threaten the electric grid. #cybersecurity #microgridsClick To Tweet

It’s not only hurricanes and cyberattacks that threaten the electric grid. Many power outages are caused by more common thunderstorms, ice storms, and scheduled brownouts. Individually and in aggregate, these disruptions can significantly affect a grid customer. In one example, a microgrid in California powered the community of Borrego Springs for nine hours after a transmission line was damaged by lightning. Here again, microgrid islanding proved itself as a way to ensure power supply.

microgrid islanding

If a fault in the utility grid causes a loss of power, a microgrid can disconnect or island from the grid and independently serve its customers via its on-site generation resources.

Nested microgrids being developed in Chicago, New York and Pittsburgh, among other locations

These are some examples of microgrids exhibiting the ability to provide backup power, resiliency, and redundancy. In these cases, the microgrids stand alone. Offering even greater promise are microgrids that are linked together or ‘nested’ with other nearby microgrids.

Still a nascent approach – but one that offers superior opportunity for resiliency (the main goal of cybersecurity) — nested microgrids are electrically interconnected so that power can be interchanged. They can share and switch between power sources to ensure optimal efficiency. For example, a solarpowered microgrid might pull the load on a sunny day while a nearby microgrid with a combined heat and power plant would take over on a stormy day.

Resiliency, a benefit often associated with microgrids, describes the ability to avert power failure or restore service quickly after a disaster.

In Chicago, Commonwealth Edison has proposed a microgrid in the Bronzeville neighborhood. When completed, it will provide resiliency and security for local residents, as well as for the hospital and police and fire headquarters. The Bronzeville microgrid would also nest with an existing microgrid at the Illinois Institute of Technology that has been in operation since 2013.

microgrid islanding

When Hurricane Sandy came ashore in New Jersey and ripped up the East Coast, 8 million electric customers lost power, but the lights stayed on at Princeton University because of  microgrid islanding.

In New York, the town of New Paltz has proposed a $12 million modular microgrid that would comprise 10 independent zones or nodes, with each having its own energy resources to serve one or more critical facilities. In all, the New Paltz nested microgrid would serve 25 critical facilities.

It’s clear that microgrids offer protection during a cyberattack because of their islanding ability, in essence creating a gap between the electrical systems under attack and the microgrids’ own assets. But microgrids are also built upon software and data communications, and if microgrids are intended to protect against the risk of cyberattacks on the utility grid, it’s essential that the microgrid itself is protected from those attacks.

Designing a truly cybersecure microgrid

In this respect, it is important to recognize that the very elements that make a microgrid resilient can also make it vulnerable. Microgrids often include distributed energy resources (DERs), such as solar panels, that require inverters to send power to consumers or the grid. One of the key enabling features of a microgrid, in fact, is the two-way data communications among the microgrid participants and with the grid to which it is connected.

Those control and communication functions can create vulnerabilities by increasing the microgrid’s attack surface — in essence presenting portals for cyber intrusions – and undermining the very resiliency that a microgrid is designed to provide.

A hacked microgrid could even be a portal that opens the grid itself to cyber attacks. At the least, building a microgrid that is not cybersecure would be a poor investment. At the worst, it could precipitate or aggravate a catastrophe.

However, it is important to underscore that a truly cybersecure microgrid overcomes these vulnerabilities. What are the microgrid design elements needed to accomplish that? That is the subject of the next chapter.

Over the next few weeks, the Microgrid Knowledge Special Report series on microgrid cybersecurity will cover the following topics:

The full report, “Microgrid Cybersecurity: Protecting and Building the Grid of the Future,” is downloadable free of charge courtesy of S&C Electric.

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