The Home of Today Can Run on Direct Current

LumenCache lets you do it over computer wires.

Lumencache panel

Lumencache Panel

That's not your ordinary electrical panel feeding lights and switches in the photo; it is doing it in DC with a LumenCache wiring system, delivering lighting and controls over CAT5 computer wire. We have waited a long time for this.

In 2015 I wrote "The Home of Tomorrow will Run on Direct Current," suggesting that you "look around your house. If you have, like me, banished incandescent bulbs, almost everything you own is running on low-voltage direct current." Today it is even more so, with cordless tools and Roomba vacuums. Only the big white goods—the fridge and oven and clothes dryer—are running on alternating current. When I wrote that post, electrical codes still demanded 14-gauge copper running to outlets every twelve feet and to light fixtures and switches.

It is a lot of copper. According to, an average home has 195 pounds of copper wire. It takes a lot of ore to make a pound of copper; it is now down to 0.7% in many copper deposits, so 27,857 pounds of ore have to be processed to make your wiring, capable of carrying 1,800 watts but probably supplying an LED that draws 10 watts. Also, as noted in a recent post, increasing demand for copper for everything from heat pumps to electric cars to wind turbines is squeezing the supply of copper and driving up the price.

Much has changed since that 2015 post, including the electrical codes, and we are no longer talking about the home of tomorrow; it can be the home of today. Derek Cowburn is CEO of LumenCache, which designed a platform to replace 110V AC power with a standard that makes sense for our DC world. It feeds CAT5 computer wiring to LED lights, the same ones you can buy today. Except you don't need the electronics, the rectifiers, and transformers that convert the AC to DC, so the fixtures should be cheaper and last longer.

And soon, it will power more than just lighting. Cowburn tells Treehugger, "I am designing generation two now, to support up to 300 watts per channel. I can power every TV on the market, and possibly, small fan coil heat pump units. That's why I am such a huge fan of Passivhaus," because it reduces demand so much.

lumencache panel


This is what I recently called ephemeralization, Buckminster Fuller's term for doing more with less. "Instead of trying to find enough copper to generate enough electricity to run all the motors and compressors in our cars and heat pumps, maybe we should first try to reduce demand." Cowburn has ephemeralized our electrical wiring and control systems, running both on much smaller wiring with far more sophisticated possibilities for control.

wall switch with sensors
wall switch with sensors.


His light switches don't just turn on and off, but have sensors for temperature, ambient light, and motion. As we noted recently, this information is critical to monitor and fix air quality. This is a much more reliable method of control than the wireless mesh systems like my Hue bulbs; it just makes sense to merge the power supply and the control.

Typical small panel
Lumencache panel.


It is a simple panel. You plug in the standard module and then just run CAT5 to your lights, without danger or expensive trades. Because it takes so little power to run the lights, a backup power supply like the ITEHIL I recently reviewed can plug right into the system.

So why isn't everyone building with these now? It would save thousands of dollars per house, but it has taken ten years to get to this point. Cowburn tells Treehugger that builders wanted proof of reliable operation, longevity, price parity, ease of installation, and wide fixture selection, and LumenCache has finally checked all the boxes needed to take it beyond the niche proof-of-concept installations they have done until now. "We’re on target to demonstrate the first gen2 brand at some shows in October, then ramp-up with some help from a IndieGogo crowdfunding campaign to raise brand awareness. That should get us through the certifications and into production by the end of the year."

It is a dozen years since I first suggested a big step in building: Go DC. When I reviewed a commercial Power over Ethernet (POE) system a few years ago, I noted, "The energy savings are nice, but what really impresses is the control, the flexibility, and the elimination of layers of wiring installed by different trades, the elimination of high voltage so that anyone can move or replace a fixture as needed. In the future, I suspect our homes also might be wired this way, eliminating most of the problems people are having with the so-called smart home technology we have now. It just all makes so much sense."

It still does, and it looks like it might actually finally happen with the LumenCache platform.

View Article Sources
  1. "Copper Facts: Copper in the Home."

  2. "Back-of-the-Envelope Calculations: Percentage of Copper in Ore." Science Education Resource Center at Carleton College.