The balance of supply and load on the grid must be continuously maintained. If it is not, the frequency of the AC power supplied changes.
If the grid is underpowered, the frequency falls. If the grid is overpowered, the frequency rises and the excess energy needs to be used or stored.
Our installations show that UltraBattery offers a performance superior to the traditional gas-peaking power plants typically used for grid frequency management. This is because UltraBattery responds instantaneously, while gas plants provide the requested power level seconds or minutes after receiving the request. UltraBattery also allows excess energy to be stored rather than simply wasted, as it is in a traditional power plant.
In the US we have installed MW-scale UltraBattery storage to supply frequency regulation to the PJM grid in Pennsylvania. We’re also developing this application into dual-purpose storage – grid-regulation batteries that turn immediately into standby batteries if there is a blackout.
Few batteries can maintain the constant fast cycling of frequency regulation services. UltraBattery loves it, year after year.
Dual purpose applications: where energy storage is heading
UltraBattery: Leading the field
In an exciting project for UltraBattery technology, a large industrial client in the US with a requirement for short-term MW-scale ride-through for critical infrastructure in a grid event has teamed up with Ecoult and a major energy supplier to develop an active dual-purpose UltraBattery system – one of the first such energy systems in the world at this scale.
Revenue-offsetting standby battery cost
When the grid is operating normally, the battery owner can receive significant income providing non–fossil-fueled, fast-acting ancillary services to the grid operator. Ecoult’s existing frequency regulation installations show that they can make tens of thousands of dollars per month in this market.
Dual purpose reserve
In the dual-purpose case the system is managed so that the required ride-through capability is always held in reserve. With UltraBattery, this reserve is available whether or not the battery is at a high state of charge. UltraBattery is an extremely tolerant technology and is not harmed by infrequent excursions outside its standard operating window (providing the control systems are adequate).
Because of this, even in the worst-case scenario – where maximum ride-through is required at the moment when the batteries are at a low state of charge (due to whatever high-rate services are being performed) – UltraBattery can still cover the event by dipping below the battery’s everyday minimum discharge level. Many other battery chemistries cannot safely operate – even infrequently – outside their minimum-to-maximum range.