We’ve been seeing more and more luxury homes and second luxe homes going off grid with solar PV systems and battery storage. And now luxury homeowners seeking protection against power outages and contractors looking for something new and compelling to sell them will have a find in RoseWater Energy Group’s Residential Energy Storage Hub.
The unit, which is debuting at the CEDIA (Custom Electronic Design & Installation Association) Expo in Indianapolis, Ind., Sept. 5-8, provides up to 10 kilowatts of uninterruptible power to selected circuits and 12 kilowatt hours (kWh) of energy storage, integration with a solar photovoltaic array, wind turbine or generator, and power enhancement. It also is ready for demand response (DR) load management capabilities with utility smart grid programs.
A string of 24 Axion maintenance-free lead carbon batteries, which represent an advancement over lead-acid batteries, are used to store several hours of power for homes during blackouts and power failures. You could power computers and electronics for six hours or more, says Joseph Piccirilli, managing director of RoseWater Energy Group.
The batteries have a longer life cycle than lead acid batteries and can be cycled 2,500 times to a full discharge. Piccirilli says testing of partial discharge was stopped at 100,000 cycles.
The series-connected battery string is accompanied by two bi-directional DC to DC converters (48 to 400 volts), where power is stabilized. A built-in inverter handles the conversion from a DC to AC. “We convert all power to DC, stabilize it, and convert it back to AC,” says Piccirilli. “It’s a dual conversion to guarantee pure sine wave, constant 110v/60Hz.” The result is stable and reliable power for electronics. Piccirilli says despite the conversions, power loss is minimal, with conversion efficiency percentages in the high 80s and low 90s. An input for a generator ensures that power, which can often fluctuate, will be stabilized as well.
The DC to DC conversion corrects common power quality problems with the utility supply via automated power factor compensation, automated surge assist, frequency control and voltage regulation to correct for spikes and sags.
And yes, you will absolutely need someone on staff or a partnering electrician with a high-voltage license to install these.
An Energy Router contained in the unit has the software to track energy loads and sources and route energy to your selected circuits. There’s also a display control panel, automatic transfer switch with manual bypass, a main input circuit breaker, and an anti-islanding relay to prevent back feeding to the grid.
The demand response function can be set up to do non-critical load shedding if the home is enrolled with a utility smart grid program that offers incentives to turn off or turn down energy-intensive loads for power needs.
Larger Systems Possible
The system will be capable of paralleling up to five units to extend the total power and energy storage capability to 50 kW/60 kWh. System configuration is for a 110/220 split-phase electrical service. Three units can be connected to provide 220 VAC 3 phase. It is UL-approved and packaged in a NEMA 3 rated outdoor enclosure with an 1,800-pound battery system, ventilation fans and ducting.
Each energy hub can be used with solar electric system of up to 10 kw or a wind turbine. It can also be used with a generator alone or in combination with a renewable energy system. Piccirilli says it will interface with any energy management system as well. “We can give them our software to manage the storage and monitor [battery storage] on a cell-by-cell basis.”
The Residential Energy Storage Hub will retail for a pretty $45,000, and Piccirilli says it’s for large homes with $100,000-plus control systems. The rollout will be tightly controlled—the companies are not going to builders and developers yet—and Piccirilli personally wants to oversee the first 10 to 20 installs. Systems can also qualify for a 30 percent U.S. federal renewable energy tax credit for use with a solar system.
“This is not a rational purchase,” he says, meaning it’s strictly for the luxury market. “We want to give homeowners a lifestyle change that’s good for them and good for everybody. This is a system that integrators can go back to their customer base for or get new customers with.”
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