How University Microgrids Give Campuses Intelligent Control of Energy Assets and Use

Read the next article in our special report series on university microgrids. What makes up a true microgrid? And how do microgrids protect campuses from outages, as well as optimize renewable energy?

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A recent survey of 2,000 U.S. voters by the Civil Society Institute found that most had never heard of the term microgrid, or they had heard of it but had the wrong impression. But when microgrids were explained to them, they showed a strong predisposition to the concept.

“Once people understand microgrids, they see the importance of them in their community,” said Andrea Camp, senior project manager at the institute, a nonprofit public policy think tank.

Although microgrids have existed since the electric grid emerged over a century ago, the technology started regaining traction following Superstorm Sandy in 2012. Today, microgrids are viewed as a key component of the emerging smart grid, as well as the “smart campus” vision as defined by Siemens in their new Campus of the Future report. Navigant Research, a Guidehouse company, forecasts 10-fold growth for the microgrid industry from 2019-2028.

So, what is a microgrid, and why is this technology becoming an important part of the U.S. energy landscape?

A microgrid is a self-sufficient energy system that runs 24/7/365 and serves a discrete footprint, such as a college campus, hospital complex, business center or neighborhood. In a sense, a microgrid is the electric grid in a compact form because it generally contains the same basic elements: generators to produce energy, a means to distribute the energy, a means to control the energy supply and demand, and customers who use the power. Contemporary microgrids also often include energy storage systems, typically batteries, to help balance and optimize supply and load while providing backup supply capacity. And, microgrids have begun to incorporate electric vehicle charging stations, thus connecting the distributed electricity supply grid to a cleaner transportation fleet.

Intelligent control of your energy assets and use

But a microgrid is more than a mere grouping of energy assets. What sets a microgrid apart is its microgrid controller, the brain of the operation. This is a relatively inexpensive software-driven system that gives the microgrid the ability to undertake various beneficial functions, among them islanding from the central grid. If a power outage occurs on the grid, the controller signals the microgrid to separate from the grid to avoid the disruption. Its generation and storage systems ramp up as needed to become sole providers of power to the buildings the microgrid serves. Islanding can be designed to occur so seamlessly that those within the building are unaware that they are no longer on grid power but are being served by the microgrid controller and associated local generation assets.

Microgrids as protection from outages

This ability to island produces the hallmark benefits of a microgrid: reliability, grid independence, and resilience. University microgrids are able to keep the power flowing on campuses, at least to critical loads, even when their neighbors are in the dark. This is important as campuses often serve as community shelters during an emergency.

The ability of a microgrid to operate independently from the electric grid is especially important in North America because the magnitude of the grid and its interconnectedness make it particularly vulnerable to power outages. The U.S. grid encompasses hundreds of thousands of miles of high-voltage electricity transmission lines and millions of miles of lower voltage distribution lines that deliver power from thousands of generating plants to hundreds of millions of electricity customers. Because all of these elements are interconnected, a single tree falling on a power line can cause a cascading failure that knocks out power in several states, a lesson the U.S. learned during the Northeast Blackout of 2003.

University microgrids can be designed to capture market opportunities associated with grid integration such as renewables balancing, demand response and spinning reserves.

Microgrids to optimize renewable energy

While islanding may be the most notable characteristic of a microgrid, it is but one of several valuable functions made possible because of the intelligence of the microgrid controller. The controller can optimize for various outcomes. It might be programmed to maximize renewable energy or minimize cost or carbon output. The microgrid’s intelligence also can be leveraged to manage building electrical loads efficiently—when electricity prices are high, it can reduce energy flow to buildings or operations that are not essential, such as classrooms not in use at that time. Microgrids can also be designed to capture market opportunities associated with grid integration such as renewables balancing, demand response and spinning reserves.

Microgrid misconceptions

Microgrids are often confused with backup generators; in fact, they are much more. Backup generation, typically fueled by diesel or natural gas, is deployed (by definition) only when needed and typically using simple control systems. Backup generators alone do not enable independent operation from the grid during an outage and are typically limited to supplying short-term emergency power. In contrast, a microgrid combines localized distributed generation assets. As we described earlier, these assets may consist of a combination of reciprocating engines, solar PV, fuel cells, cogeneration, energy storage and other forms of energy supply. They serve a set of interconnected loads by way of a sophisticated controller that enables automated grid islanding and various levels of system optimization.

As a result, a robust microgrid has many layers of redundancy. If one asset is too expensive or does not operate—perhaps it’s a cloudy day and the solar panels are not producing energy—then another form of generation, imported power and/ or energy storage supply comes into play. This redundancy also proves beneficial when certain fuels become scarce. For example, after Hurricane Maria, Puerto Rico found itself short on the diesel required to run many of its backup generators.

But that’s not the only reliability advantage of a microgrid over a backup generator. Because most microgrids operate 24/7/365, performance is constantly monitored. Need for repairs or maintenance becomes evident and should be quickly resolved. The same is not true of backup or emergency generators. Since they typically are only run when needed, they sit idle except for periodic required testing. Too often, any malfunction only becomes apparent to a facility manager during a power outage when the backup generator is suddenly called upon to perform. When this happened at a New York hospital during Superstorm Sandy, hospital staff were forced to evacuate patients, and, in some cases, carry them down several flights of darkened staircases.