Energy Storage Power Electronics: Page 2 of 6
Inside this Article
Eguana Technologies designs and manufactures power electronics for distributed smart grid and microgrid applications. Founded in 1999, Eguana initially focused on developing low-voltage inverters for utility-interactive fuel cell systems. It launched its first-generation Sunergy inverter in 2010 and second-generation Paralex inverter for thin-film PV applications in 2012. In 2014, Eguana introduced its Bi-Direx inverter for grid-tied energy storage systems. The inverter’s initial target was the European energy storage market, where it shipped more than 4,000 units in 2014–2015. In 2015, Equana launched the AC Battery, an integrated battery-ready power electronics platform for solar self-consumption and backup power applications, in the North American market.
The flexibility of Eguana’s AC Battery system allows for integration with diverse storage technologies that include LG Chem’s lithium-ion batteries, Aquion Energy’s saltwater electrolyte Aqueous Hybrid Ion products and Primus Power’s flow batteries, as well as VRLA lead-acid battery models from various manufacturers. Eguana manufactures five Bi-Direx inverter models. Developed for the US market and certified to UL 1741, the B5048US model is designed to integrate with 120/240 Vac 60 Hz electrical services. On the dc side, the B5048US has a nominal voltage of 48 Vdc and an operating range of 40–66 Vdc.
The standard AC Battery configuration couples Eguana’s Bi-Direx inverter with LG Chem M4860P2S2 lithium-ion batteries configured at 48 Vdc nominal (42–58 Vdc operating range) for use with the AC Battery product. Five battery storage system capacities are available with ratings at C/1 of 6 kWh, 9 kWh, 12 kWh, 15 kWh and 18 kWh. The batteries are rated for 4,000 cycles at 90% depth of discharge (DOD), 25°C and C/1. Users can ac-couple solar arrays to the system via third-party string or microinverters, which perform system MPP tracking and array dc-to-ac conversion. The system's SunSpec-compliant Modbus communications interface integrates with third-party energy management systems and gateways that enable self-consumption functionality. Eguana Technologies’ AC Battery carries a standard 10-year warranty.
Eguana Technologies • Calgary, Alberta, Canada • 403.508.7177 • eguanatech.com
Founded in 2006, Enphase Energy is largely responsible for creating the modern microinverter product class. With an eye toward current and projected changes in net energy metering programs and policies that limit exporting solar energy to the grid in the US and beyond, Enphase developed its AC Battery for global markets that benefit from or require self-consumption functionality or energy time-of-use optimization. After announcing the product in October 2015, Enphase began marketing the current design in February 2016 and expects US availability in late 2016.
The AC Battery is a scalable, modular energy storage system. Designs can ac couple it with Enphase’s microinverters and module-level online monitoring platform. Enphase also designed the AC Battery for compatibility with any grid-tied system, regardless of the brand and model of a given system’s inverter or modules, with the addition of its Envoy-S Metered gateway and Enlighten monitoring products.
The Enphase AC Battery uses lithium iron phosphate cells configured to provide 1.2 kWh of capacity. It can discharge to greater than 95% of rated capacity and has a round-trip cell efficiency specification of 96%. Weighing only 55 pounds, the AC Battery is designed for single-person installation and interconnection with standard household wiring. Its enclosure is NEMA 2 rated for indoor installation in an unoccupied space. Certifications to UL 1741, UL 1973 and UL 9540 are pending. The AC Battery carries a 10-year or 7,300 cycle warranty for greater than 80% of its initial rated capacity.
Enphase Energy • Petaluma, California • 877.797.4743 • enphase.com
Founded in 1945 in Pettenbach, Austria, as a welding equipment manufacturer, Fronius today focuses on products and systems for welding, battery charging and solar energy applications. Fronius USA is headquartered in Portage, Indiana, where it develops and manufactures string inverters and related equipment for the US solar market. In 2014, Fronius began rolling out its SnapINverter generation of single and 3-phase string inverters for solar projects in North America.
Fronius gained its early experience with power electronics for energy storage applications in the European self-consumption market, where the company combined its long history in battery charging– equipment design and manufacturing with its solar product development efforts. With established availability in Europe, the Fronius Energy Package includes a Fronius Symo Hybrid multiport inverter, a lithium iron phosphate Fronius Solar Battery and a Fronius Smart Meter to monitor system energy flow.
In 2015, Fronius shared the headlines with Tesla as one of two inverter manufacturers developing a high–dc-voltage multiport inverter for integration with Tesla’s Powerwall Home Battery. Fronius’ initial relationship with Tesla stems from the welding systems it supplies for manufacturing Tesla electric vehicles. Scheduled for a Q4 2016 release, Fronius’ first dc-coupled storage system for the US market is its multiport Primo Hybrid. The Tesla-compatible inverter will be available in power classes ranging from 5 kWac to 11.4 kWac and will feature three dc inputs: two solar MPP trackers and one battery input. The MPP trackers’ input voltage range is 80–600 Vdc. For seamless integration with Tesla’s Powerwall battery, the inverter’s dc bus operates at 350–450 Vdc. Both the Fronius Primo Hybrid inverter and the Tesla Powerwall battery are rated for outdoor installations.
Fronius has also partnered with JLM Energy to integrate Fronius inverters with JLM’s lithium iron phosphate battery systems, as well as its products that monitor and control self-consumption and energy time-of-use optimization. JLM’s battery products and the Fronius inverters communicate via the SunSpec-compliant Modbus RTU interface. JLM’s residential solutions couple Fronius’ standard Primo inverter with JLM’s Energizr 200 storage system to create an integrated system for self-consumption, peak shaving and load shifting applications.
Fronius USA • Portage, Indiana • 219.734.5500 • fronius-usa.com