Community Energy Storage and the Smart Grid: A Powerful Union

.

By Ali Nourai

As we increasingly turn our attention to develop viable solutions for energy storage, one device stands apart from others: Community Energy Storage (CES).

CES is a small distributed energy storage unit connected to secondary transformers that serve a few houses or small commercial loads. CES can also be configured to act like a virtual substation battery. In this layout, a number of CES devices are aligned, so they feed into one substation through the CES integrated control system. These devices operate together like one fleet, which yields an aggregate storage capacity of multi megawatts and multi-hours to benefit the grid.

You might also be interested in … . Energy Storage: Making It Work with Generation Applications . Energy Storage Outlook: Nano-Enabled Batteries a $2.5 Billion Global Market in Five Years . Stationary Battery Storage Expands to Strategic Markets . Two DOE-Funded Pilots Will Test New CES Strategy with Li-ion Batteries

So, if we join CES to the Smart Grid, we could create a powerful union that offers the greatest potential. The Smart Grid can control distributed CES devices to act locally or for the greater benefit of the utility, if necessary. CES has several drivers that make it an especially attractive and viable storage device.

Distributed Generation

CES devices can integrate renewable resources into the grid for distributed generation. These devices could help smooth, shape, and firm renewable energy, as well as help to level out the load, which would reduce generation needed during peak times and decrease utilities’ capital investment. Furthermore, using CES devices where capacity upgrade needs are greatest would defer capital spending on transmission and distribution systems and, instead, pay for most of the batteries in CES.

Demand Response

The variability of energy production from distributed renewable resources prevents them from participating in demand response (DR) programs, since there is no guaranteed response to act on DR signals. CES devices enable the use of renewable resources for demand response programs. Stored energy in these devices would serve as back-up resources for DR, when the renewable technology is not producing energy.  

Batteries

CES devices can use technology and batteries similar to those within plug-in electric (PHEV) and hybrid electric (EV) vehicles. As manufacturers produce batteries for CES, EV, and PHEV at higher quantities and competition increases, their cost should decrease. Consequently, it would be expected that the cost of CES devices would also decrease faster than other storage technologies.

Compared to larger batteries located in substations, CES devices offer several advantages, including:

• More reliable back-up power to utility customers, since devices are located closer to customers and, thus, experience less line loss
• More scalable, flexible implementation, since they consist of many small units
• Easier to install and maintain  

Standardization

Standardization is a goal for certain features of CES devices. This will help to reduce cost and increase the adoption rate. American Electric Power (AEP) created initial open source specifications to encourage this process.

Moving CES Forward

CES devices can potentially overcome the top three barriers to storage development:

• Highly competitive pricing could be achieved
• High direct value can be offered to customers
• A variety of different storage technologies can be used

Whereas there are no major technical barriers to implement CES devices, pilot projects need to be conducted to develop and test some remaining details. Most significantly, algorithms must be developed to enable two systems on different sides of the meter to interact.

Note: This blog post includes excerpts from KEMA’s Utility of the Future leadership guidebook, “The Promise of Energy Storage.”

Ali Nourai is an executive consultant at KEMA, which is a leading authority in energy consulting and testing and certification. Contributing authors: Ralph Masiello and Rick Fioravanti.

.  

Stay connected with SGN …

Smart Grid Discussions: Get LinkedIn with Jesse

Smart Grid on Facebook

Follow Us on Twitter

Try our RSS feed

Get our email digest