If you’re like many people, you want your home to be well-lit and bright. Lighting can be a big energy-user, however. The U.S. Department of Energy and the U.S. Energy Information Administration estimates that a home’s lights consume up to 14 percent of residential electricity usage. Needless to say, energy use can add up quickly every time a light is left on. The adoption of energy-saving LED lighting is helping homeowners cut costs significantly, and some new technologies are paving the way to even greater savings.
Indianapolis-based technology developer, LumenCache, has combined the energy-saving power of LEDs with a communications platform that allows the LED lights to be wired into a home with Ethernet-grade Category 5 or Category 6 low-voltage wiring instead of the customary 110-volt high-voltage electrical wiring. Cat 5 or 6 cabling is used frequently in homes to facilitate control and media streaming to computers, TVs, and other devices. By utilizing this type of cabling, the LumenCache system is able to join this network, ostensibly able to synchronize its operations with other Internet of Things devices, and be managed and controlled by many popular home automation systems, including those from Control4, Crestron, and Savant.
Also appealing is the fact that the LumenCache system uses the Ethernet cabling to deliver power to the LED lights. This is possible because LEDs use low-voltage DC power, like your computers and electronics. Rather than having to convert high-voltage AC power to DC power, which screw-in LED lamps must do at the bulb, DC power is sent directly over the network cabling. This approach also reduces some energy waste that occurs at each AC/DC adapter. (Wall warts, “bricks,” and other adapters emit this waste energy as heat, which is why your laptop computer adapter can get hot.) Additional energy can be saved in the automation of the system through a plug-in gateway with LumenCache software that can set the lights to operate at an 80 percent intensity level instead of at 100 percent.
IndyCar Champ Saves $600 a Month with LumenCache LED Lighting System
When three-time IndyCar champ Scott Dixon and his wife Emma built their new home in Indianapolis, they asked LumenCache president Derek Cowburn if his company’s new system would make sense to incorporate into their construction plans. He said it was perfect.
A total of 136 recessed lights are controlled by LumenCache’s 12 Power Distribution Modules and 70 Switch Pucks, all in two 40-inch enclosures and a 28-inch enclosure, along two 12-volt batteries for energy storage.
The LumenCache lighting system and other electronic systems in Dixon’s home are controlled by an Elan g! automation system. The energy-efficient LumenCache system has helped make a huge dent in their electricity bills: In their new home, they pay only $150 a month for electricity, compared to $700 in their previous home.
The biggest problem was finding the right LED bulbs for 17 decorative chandeliers and sconces chosen for the home. “Emma spent a lot of money on fixtures and was really concerned about look of the bulbs. She loved that filament-style look,” Cowburn says. At the time, it was hard to find LED lights for these fixtures, let alone ones that could be powered directly from DC, rather than through AC/DC converters. But Scott went to 12voltmonster.com and found some appropriate candle-style bulbs for the fixtures.
LumenCache will also be included in the Team Orange County House for the 2015 Solar Decathlon green home competition in Irvine, Calif., in October.
In LumenCache’s system, Category 5 or 6 cabling is wired to each light fixture and wall switch—with two-way home runs to each light or groups of lights that pull more than 7 watts—and is routed to LumenCache’s power distribution panel located centrally in an equipment room or basement. There, installers simply plug the cables into the power distribution panel, add necessary drivers for each lamp and any accompanying sensors into the appropriate puck sockets—and a low-voltage LED network is created.
Other system components include a high-efficiency AC/DC power supply or charger to convert the home’s AC power to DC, and a battery for storage so the lights will continue to work in a power outage.
The 12-volt AGM (Absorbent Glass Mat) battery stores 18 amp hours of power for emergency lighting. With 16 lights on at full power, this will provide 15 minutes of illumination, says LumenCache’s founder Derek Cowburn, though in a power failure the lights can shut off and be used only as needed. Additional batteries can be added; the lights can also utilize energy generated from a solar power system. Having backup power on hand not only keeps a house lit in a power outage, but lets you take advantage of your electrical utility’s demand response or time of use pricing programs. You can use the backup power during more expensive rate periods.
To prove the effectiveness of this approach, LumenCache incorporated its system into the ReNEWW House (Retrofitted Net-Zero Energy, Water and Waste) show home built at Purdue University. Here, two solar panels were assigned to the DC-Powered LumenCache lighting system to power all the home’s LED lights. Such DC microgrids appear to be the way of the future, as interest grows in powering devices like electric car chargers with solar power without going through that troublesome AC/DC conversion.
In the meantime, LumenCache is looking at home and commercial markets and offers a starter pack for builders that provides several LED lamps and switches for rooms, including the living room, kitchen, bath, two bedrooms, and an entry, for about $5,000 retail. Of course, there will also be a labor charge to have the system professionally installed, but it should be no more than 10 percent higher than the installed cost of an old-style 110-volt AC dimmed LED lighting package, says Cowburn. Depending on the scope of the project and the size of the home, the installation costs can even be less. When more than 85 lights will be installed, LumenCache tends to cost less than AC-powered LED systems, says Cowburn. And because it’s only wired through cabling, the best time to have a system installed is while a home is under construction. EH
Steven Castle is a freelance writer and editor. He has covered home technologies for more than 20 years, and also writes about green tech and design. www.stevencastle.com