Given the proliferation of renewables — plus the dramatic growth rates predicted for solar and wind power over the next year or two — plenty of people are looking to storage as the way to save us from renewable intermittency. But, storage is pricey. And, given the potential for long stretches of inclement weather that knocks solar PV output down or fails to turn the wind turbines, the storage we have available today is unlikely to be sufficient for the power grid’s needs.
What the power needs is a more holistic approach, a combination of distributed energy resources – including storage and demand response – working intelligently together to keep grid operations running smoothly.
Hybrid storage is relatively new concept that does just this. It combines multiple resources to provide efficient physical and process storage in a cost-effective way.
How does it work? With the Symphony by Enbala platform, the solution is a network that leverages a diverse portfolio of energy storage technologies to provide a combination of high efficiency, power and energy storage capability at a lower cost than typical energy storage systems commercially available today.
Loads participating in Enbala’s various engagements include universities, water treatment facilities, chiller operations and local schools. The result is a network of demand-side resources capable of providing a variety of grid services, such as rapid frequency response, constant power output for short duration, system load following and ramping, as well as power and energy absorption.
The platform also can accommodate devices, such as batteries and flywheels, to be dispatched with the rest of the network. A high power device, such as a Li-ion battery, is an ideal complement to the process storage network.
To make the most of hybrid storage, a system must continuously optimize use of each form of storage and take advantage of the best characteristics of each resource.
For instance, the fast response and ramp rate of the battery system will allow the network to accurately respond to the high frequency fluctuations in the signal for regulation service. The large, aggregated energy storage capacity of the thermal, dissolved oxygen and gravitational potential will provide enough energy to address longer duration services such as peak reduction for local capacity constraints or customer demand management applications. Together, the process storage and battery storage devices deliver a comprehensive solution for utilities and the ISOs that connect to their systems. Distributed energy resources may be scattered throughout the grid but, in aggregate, we make them truly useful to the grid as a whole.