Distributed Energy Storage Systems: Page 4 of 6

Carl Mansfield
General manager of energy systems and services group, Sharp Electronics, sharpsmartstorage.com

What products and services does Sharp offer for solar-plus-storage applications?
Sharp offers the SmartStorage energy storage solution, which is designed to reduce peak demand. SmartStorage uses software to provide continuous remote monitoring of a building’s energy demand. Peak demand charges are the fastest-growing part of utility bills for commercial and industrial entities, and in some cases they can represent up to 50% of a company’s monthly utility bill. Our system uses predictive controls to limit a facility’s electricity demand by selectively releasing stored energy, offsetting spikes in demand. The SmartStorage system predicts where those peaks are going to occur, along with their magnitude. We discharge the battery during those peaks so that the actual net consumption is much lower than it would be otherwise.

What is the ideal physical and economic environment for Sharp’s SmartStorage solution?
We target commercial and industrial customers who are paying high demand charges—typically above $20/kW per month—in California, New York, New Jersey, Massachusetts and Hawaii. We don’t find specific property types are always good or always bad targets for our product; it depends on the individual energy usage profile, which the site’s operations dictate. However, schools tend to be good targets because their set daily cycle usually results in a narrow peak load from early morning to about lunchtime.

What makes energy storage systems ideal for demand reduction applications?
Battery solutions can achieve demand reduction without requiring changes in a site’s operations. Further, lithium-ion battery–based systems do not require substantial space. Our system can work as a hybrid solution deployed with PV, or as a stand-alone storage solution. We find that hybrid installations generally provide better returns. PV tends to narrow the width of the peak load and storage will lower its height.

What are the primary deployment challenges associated with demand reduction solutions?
This is a new technology and requires that we educate customers, who typically do not have a good understanding of rate structures that bill separately for demand and energy. We also have to provide a performance guarantee to create a bankable product. It is also challenging to predict future utility rates. While the prospect of rate redesign potentially risks future savings, our system is fully upgradable after deployment. We can easily and remotely adjust operating parameters to account for tariff changes.

Dean Middleton
Senior sales director for renewable energy, Trojan Battery, trojanbattery.com

What product platforms does Trojan Battery offer for solar storage systems in the US?
Trojan is the largest battery manufacturer that focuses on deep-cycle energy storage. We offer a range of deep-cycle products, including flooded and maintenance-free VRLA [valve-regulated lead acid] technologies. Our products have a long history in the global off-grid market and are also used in both residential grid-tied and backup systems in the US.

Which of these products are best suited for stand-alone microgrid or nanogrid applications?
Trojan products are designed to support stand-alone microgrid or nanogrid deep-cycle applications. The product line or model selected will depend on the application, system loads and customer expectations. In some parts of the world, we see a culture of maintenance and a willingness to care for a flooded battery to ensure maximum life. In others, the priority is on ease of use, which will favor maintenance-free AGM [absorbed glass mat] batteries. While price is a concern, it must be balanced with long-term value. Trojan’s Smart Carbon batteries are a good choice for situations where batteries operate frequently at a partial state of charge, which can quickly diminish the overall life of a lead acid battery, resulting in frequent and costly battery replacements. With batteries now one of the most expensive components of these systems, it is critical to maximize the life of the battery bank to reduce total cost of ownership.

What are the biggest challenges to the increased deployment and commercialization of distributed energy storage solutions and microgrids?
Accurately defining the load profile, or system sizing, remains one of the biggest challenges. Whether a system is off-grid or grid-interactive, it’s important to accurately define the role of energy storage, how it will function and what needs it will serve, to manage customer expectations and design a system that will deliver value over the long term. A one-size-fits-all approach to storage will result in either an oversized or an undersized system. Another issue is the rapid development of new energy storage technologies. New technologies need to prove their technical viability and cost effectiveness. Many companies that entered the energy storage space a few years ago are no longer around.

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