When a power outage occurs and the lights go out, every minute counts. Some of these disruptions may be significant enough to cause a power station to shut down, or trip in industry parlance. In these situations, electric utilities can draw on other generating units to stabilize the grid. But the issue is most units require grid power to start. Should an entire grid lose power, or “de-energize,” due to a significant event (e.g. a hurricane hits), that grid must be “re-energized” carefully beginning with a single generator — a “black start” unit — that has the ability to start without grid power.
In the past, such “black starts” usually required separate gas or diesel generators to start larger generators that are capable of providing power to the grid. But advances in battery-storage technology are now enabling some utility-scale units to black start by drawing power from a battery, rather than a gas or diesel engine.
Engineers have been chasing ways to store energy ever since the dawn of electricity more than a century ago. Those efforts led to discoveries ranging from Thomas Edison’s reversible alkaline cell — the GE founder received 147 patents touching on battery technology alone — to batteries powering modern electric vehicles. But with the exception of pumped storage, which stores and releases massive amounts of energy by moving water between two lakes built at different altitudes, grid-scale batteries remained out of reach.
But in December 2019, GE unveiled a black-start battery-storage system at Entergy Louisiana’s Perryville Power Station — part of a larger network serving 1.1 million customers throughout the state — that stores 6.4 megawatt-hours of energy, or enough to execute two black starts back-to-back (with plenty of capacity to spare) before needing a recharge.
GE’s system consists of three 40-foot-shipping-containers, loaded with 21,400 lithium-ion battery cells, connected to a series of controls to convert the DC battery energy to AC power for starting the plant.
The Perryville project took 11 months and presented an array of unique challenges. For example, this project marks the first battery-powered black start of a GE heavy-duty 7F.03 gas turbine. There are 900 of these massive turbines installed in 12 countries around the world and capable of pumping out 150 gigawatts, about the output from 150 average nuclear power plants.
With Perryville, GE added to a budding black-start portfolio. In 2017, the Imperial Irrigation District (IID), a utility near San Diego, California, performed the first black start of a power plant in North America when it charged up its renewables-based El Centro power station with only a GE battery-storage system. The 33-megawatt system allowed IID to shutter its backup fossil fuel plants while still serving 44,000 homes.
Expect battery-powered black-start technology to gain momentum, especially in sun-drenched states like Arizona, California and Hawaii. Arizona, for example, plans to add 3,000 megawatts of storage capacity by 2030, while California passed a law to accelerate storage projects in order to reach its goal of sourcing 50% of its electricity from renewables by 2030. Navigant Consulting forecasts the energy storage system market will cross $16 billion by 2025.
Says Prakash Chandra, Renewable Hybrids CEO at GE Renewable Energy: “Achieving a black start with batteries is a very big deal,” says GE’s Chandra.
Top image credit: Entergy.