Will Tesla Batteries Force Home Wiring To Go Low Voltage?

Industry consultant claims the advent of solar power and home batteries from companies like Tesla will force the reinvention of home wiring from primarily AC high voltage to DC home-run low voltage to reduce power conversion loss.


CE pros might be sitting in the proverbial catbird seat when it comes to the future of wiring homes.

With the solar revolution seemingly in full swing all across the nation, consumers are enamored with “going off the grid.” And many homeowners are counting on home batteries to be the next phase of their off-the-grid plans. Companies likes Tesla and RoseWater Energy Group are leading the way in the development of these new power storage devices for homes.

But if the battery power trend takes off, it must lead to a new paradigm in which homes will be powered more with low voltage wiring than line voltage electrical, according to a blog by CE veteran Paul Self on Buildz.com.

Indeed, will the pure science limitations of AC/DC conversion eventually force a gigantic sea change from builders, electricians and the National Electric Code itself in the way homes are constructed and wired? The answer is “Yes” that might have to happen, says Self.

Here is Self’s logic:

“An underlying issue with solar power and the Tesla battery is the fact that they run on DC while the power infrastructure in buildings is AC. Stepping power up and down from AC to DC and vice-versa wastes energy, about 20 percent is lost in the conversion. Some converters do a better job than others, but resolving this 20 percent loss is very important when working on a battery stored energy supply.

Many devices in a home could run on DC. Almost all non-incandescent light bulbs can run on DC and require a transformer to step the 110 VAC down to a 12 – 5 VDC signal for the bulb. Other devices like computers, TVs, cable boxes, and cell phone chargers all operate similarly. Appliances like electric ovens, electric water heaters, and air conditioners will require 110VAC, but most of the house is on DC.

Let me paint you a picture.

  • Sun generates 12VDC via the solar panel
  • Solar panels push power to a battery
  • The battery or the solar panel push 12VDC to a DC to AC converter (20% loss of power).
  • AC is distributed throughout the house
  • Many devices then convert the power BACK to DC (20% loss of power)
  • This all seems pretty silly to lose this much power. I am sure it is less than a cumulative loss of 40 percent power, but when your trying to free yourself of the power company, this really adds up.

If we are really going to “get off the grid,” then the design of homes will need to change beyond a solar panel on the roof and a battery in the garage.”

Home-run Low Voltage is the Solution

According to Self, low-voltage wiring infrastructure in a home-run topology back to a central power source is the answer.

“The home run part is important because DC loses power over distance due to the resistance in the wire. The gauge of the wire will also need to increase to minimize power loss. This all adds up to more copper and a distribution center with fuses in addition to the 110 volt system that is currently in the building. This is exactly how a boat is wired,’ he says.

Moreover, a wiring topology like this will allow the existing 110 volt system to be pared down because fewer devices in the home will require that amount of power, says Self.

Will this happen overnight? No. Will it be easy to phase out all the legacy devices requiring 110V? No. But the roadmap vision for the new electrical design of the home will need to happen before fully taking advantage of the Tesla battery and solar power.

About the Author

Jason Knott
Jason Knott:

Jason Knott is Chief Content Officer for Emerald's Connected Brands. Jason has covered low-voltage electronics as an editor since 1990, serving as editor and publisher of Security Sales & Integration. He joined CE Pro in 2000 and serves as Editor-in-Chief of that brand. He served as chairman of the Security Industry Association’s Education Committee from 2000-2004 and sat on the board of that association from 1998-2002. He is also a former board member of the Alarm Industry Research and Educational Foundation. He has been a member of the CEDIA Business Working Group since 2010. Jason graduated from the University of Southern California.




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