How Microgrids and Energy Storage Can Make the World’s Power Supply as Resilient as the Human Spirit
Over 20 years ago, the world watched famed Olympic gymnast Keri Strug injure her ankle landing a vault. Despite her injury, she vaulted again, landing essentially on one foot and in extreme pain—and clinching US gold for her team. In 2005, we saw Bethany Hamilton, a young surfer, win a national title just 2 years after losing her left arm in a shark attack. And in 2014, we saw Misty Copeland, a 31 year-old ballerina, who, after receiving countless rejection letters, make history as the first African-American soloist at the American Ballet Theatre in 20 years. What quality do these women all possess? Resiliency. The root of this word literally means “to leap or spring back.” Resiliency is the ability to recover, and in some cases, transform from adversity.
Resiliency is as important to the electrical grid as it is to the human spirit. It is crucial to the success, well-being and lifespan of the world’s modern power grids—and they must have the ability to bounce back from a shock.
Grids have always faced a host of “shocks.” Storms and heat waves are classic unplanned events that can throw them into a tailspin of blackouts and long-term recoveries. This is even more true of large centralized grids lacking modern design and technology upgrades. When there is an unexpected and severe event impacting some part of these grids, a huge number of people can be affected. We can, however, look to microgrids and energy storage as ways to help these grids “bounce back.”
Microgrids are smaller “grids” that maintain their own interconnected energy resources, such as generators, energy storage and energy users. Much of the time, they are connected to a main grid, and advanced analytics give them the power to analyze, predict and react to what’s happening on that grid. But, perhaps what makes microgrids most “magical” is their ability to turn into “islands.” Microgrids can isolate themselves from a main grid if it’s been shocked, e.g., knocked down for repairs or during an unexpected event. These “islands of electricity” can operate completely separately and autonomously from the main grid. This is the grid equivalent of Kari landing that second vault and winning the gold.
If a community, such as a military base or hospital, gets shut off from the main grid, the microgrid can leap into action. New York state has established a competition for $40 million to incentivize microgrids because it believes they can provide reliable service to urban, suburban and rural environments. And at Portsmouth Naval Shipyard in Kittery, Maine, a 10MW microgrid control system was installed by GE to ensure uninterrupted coverage in the event of a grid outage.
These successes, however, do not go without challenges. As more renewables come online, they create a tricky problem for grids of ALL sizes: energy supply is not always sufficient to meet full demand and, vice-versa. Energy storage technologies can help tremendously in this situation not only because they can stockpile electricity for use later, but because they help stabilize electricity flow, especially as intermittent sources such as solar and wind come onto the grid. They can even be used to re-start a grid gone black, as was recently demonstrated in California’s Imperial Irrigation District (IIID). A newly installed 32MWh energy storage system was successfully used to blackstart (i.e. start from zero in the absence of any grid support) a 50MW gas turbine plant. The advanced controls and power electronics of the system “created” a microgrid, transformed the gas turbine generator to work like an electric motor, started up the gas turbine, and then smoothly adsorbed the energy necessary for the microgrid to reconnect to the main grid.
Energy storage can also be fully integrated with existing power generation technology in the form of a “hybrid storage solution,” such as GE’s new Hybrid EGT (Electric Gas Turbine). The Hybrid EGT is the world's first battery-gas turbine hybrid systemand is a key step in the evolution of next generation grid storage solutions. “Peakers” - natural-gas-burning turbines that can quickly ramp up and pick up the slack when renewables drop off – have been used for decades. But even the fastest peakers take several minutes to reach full power, forcing operators to run them at minimum load to keep them ready. This burns excess gas, puts more wear on the machines, and costs more money. The Hybrid EGT is storage combined with a turbine and sophisticated power management software that allows utilities to control how fast the battery discharges and how quickly the turbine needs to ramp up from full stop. So, when wind farm output drops, the battery can kick in immediately and give the turbine time to start up without cutting off from the grid. The Hybrid EGT system allows the grid’s power management system to operate with higher expediency making the grid more resilient.
Through each story of human resilience above, we see individuals not only “bounce back” but transform their situations. Their resilience is innate, but it is undoubtedly fostered by the help of others. The same can be said of grids. A microgrid system plays the role of a central coordinator and fosters resiliency by making ALL stakeholders in the energy chain active participants. We see a great example of this just a short ride from the beaches of the French Riviera. Carros, France is now home to the world’s first smart solar microgrid, a system that could one day allow cities to generate more renewable energy closer to customers. GE was part of a consortium led by French distribution grid operator Enedis. This consortium worked at installing rooftop solar panels, implementing demand response technologies and creating battery storage across the grid. This activity can be analyzed by GE’s Distributed Energy Resource Management software, which meshes consumption information with forecasts from the grid and weather reports. All of this is helping transform Carros into a constellation of microgrids where consumers (or better put, prosumers) can instantly buy and sell electricity from each other depending on their needs. It is the network of supply and demand in constant communication that enables a microgrid energy management system to do its job so well that, if a “shock” hits, the grid bounces right back—many times, without anyone even noticing what happened.
On the electrifying stage that is the power grid, microgrids and storage solutions, like supporting dancers, can help ensure the resiliency of the entire performance, and therefore, its success.