Reality PV: Energy Storage for Renewable Integration Gaining Momentum
Energy storage was a key theme at this week’s Intersolar North America conference in San Francisco, where the PV Energy World Stage special exhibit focused on how storage can facilitate the increased integration of solar energy assets onto the grid.
This was actually a continuing theme from the European version of Intersolar last month, where, as Greentech Media observed, several solar module manufactures showcased their technologies paired with energy storage systems as a means of product differentiation.
And while additional technology partnerships were announced at this week’s show, some still insist that energy storage is not yet commercially viable.
Despite what the contrarians might have us believe, there are a number of large-scale energy storage systems globally that are either currently operational or are expected to come on line in the next six to 12 months. Some of these projects, like the 32MW/8MWh storage solution at the AES Laurel Mountain Wind Farm in West Virginia, are used for renewable energy integration and ancillary services like spinning reserve or frequency regulation.
Moreover, new projects have been announced involving major utilities deploying grid energy storage alongside solar photovoltaic (PV) arrays to demonstrate a number of applications, including voltage and frequency support, PV firming and ramp-rate control.
As we’ve discussed previously, fast, flexible and scalable energy storage solutions (such as advanced battery systems) can expand the effective capacity of traditional grid infrastructure to enable the integration and delivery of renewable generation.
Since generation from renewable sources is unpredictable, it becomes difficult to schedule and manage traditional generation assets to compensate. In addition, the continuous change in generation can result in imbalances and volatility, increasing the area control error (ACE), which measures the generation and demand imbalance (usually on a second-by-second basis).
Grid operators are struggling to respond to these changes, and options such as adding additional gas turbines to compensate for the variability of renewables not only counteracts the benefits and purpose of deploying renewable sources, but are also less effective in providing the fast response needed. Energy storage, on the other hand, can technically address most of the issues associated with intermittent renewable energy generation, including by shifting energy in time to “smooth” the output of renewable generation or reduce the peak load on constrained transmission assets.
There is a strong business case for using energy storage systems for renewable integration—especially when the solution is used for multiple applications—and as the number of commercial projects being announced or coming online indicate, utilities and power producers agree.