[Multihullgirl]

This feller at the U of Toronto thinks so:
New technique offers spray-on solar power - U of T Engineering News

 

[UnionPacific]

No. Efficiency will be a big issue, if it works at all.
What we are lacking are good places to put solar. We are also held back by our love of 120/230 volts. You could LED light an entire house with one solar panel, and a battery. But we keep our 120volt lights for whatever reason.

 

[IStream]

No. Efficiency will be a big issue, if it works at all.
What we are lacking are good places to put solar. We are also held back by our love of 120/230 volts. You could LED light an entire house with one solar panel, and a battery. But we keep our 120volt lights for whatever reason.

Watts is Watts. 120V or 12V doesn't make much difference if you design the LED circuit properly.

 

[travellerw]

No. Efficiency will be a big issue, if it works at all.
What we are lacking are good places to put solar. We are also held back by our love of 120/230 volts. You could LED light an entire house with one solar panel, and a battery. But we keep our 120volt lights for whatever reason.

I'm not so sure you understand the problem..

Frankly I can think of no cheap way to convert an existing house from 120V AC lighting to anything else. I mean seriously you would need to rip walls apart and pull wire out.

Now I can hear a few of you thinking "Why not just run low amperage DC over the existing lighting wires". That would be fine if the electrical code for the last 100 years forced a separation between lighting and plug circuits. You will be hard pressed to find a house with lighting circuits and plugs completely separated, even new homes.

On another note.. AC LED lights with a buck/boost circuit are only %15 less efficient that standard LED lights. Frankly lighting is small potatoes when talking about standard residential.

 

[UnionPacific]

Frankly lighting is small potatoes when talking about standard residential.

A lot of small potatoes fills a truck. The USA has 132 million homes.

I mean seriously you would need to rip walls apart and pull wire out.

You can chase wiring with new wires, but no need. a simple disconnect from 120, and run a few new wires with a chase. However the buildings made from scratch should be the first low volt wiring candidates.

 

[UnionPacific]

Watts is Watts. 120V or 12V doesn't make much difference if you design the LED circuit properly.

there are still losses, LED modules run on DC, at least all the ones I know of. The AC is converted, at a loss.

 

[capta]

there are still losses, LED modules run on DC, at least all the ones I know of. The AC is converted, at a loss.

Are you advocating two separate wiring systems? One for lighting and the other for appliances? The more complicated something becomes, the more expensive it becomes. There is a certain point of diminishing returns, where the savings on electricity for running LED's may not offset the cost of doubling the wiring during construction.
I read somewhere that the average homeowner only keeps a home for 5 years, which would also be problematic economically with the more complicated/expensive construction.
I have no doubt that in time changes will come, but I don't see them in the near future.

 

[Minnewaska]

You guys channeling Tesla and Edison?

 

[UnionPacific]

Are you advocating two separate wiring systems? One for lighting and the other for appliances? The more complicated something becomes, the more expensive it becomes. There is a certain point of diminishing returns, where the savings on electricity for running LED's may not offset the cost of doubling the wiring during construction.
I read somewhere that the average homeowner only keeps a home for 5 years, which would also be problematic economically with the more complicated/expensive construction.
I have no doubt that in time changes will come, but I don't see them in the near future.

Lights will still be wired in, and the low voltage wiring would be far cheaper.

 

[mbianka]

No. Efficiency will be a big issue, if it works at all.
What we are lacking are good places to put solar. We are also held back by our love of 120/230 volts. You could LED light an entire house with one solar panel, and a battery. But we keep our 120volt lights for whatever reason.

Speak for yourself! I've been using a home built whole house LED lighting system in my house for years:
THE BIANKA LOG BLOG: WATTS GOING DOWN ON LAND AND SEA
I actually came up with this idea from using LED's when living on the boat. I can walk through any room in my house without turning on a light from dusk to dawn. Really puzzled the neighbors after Hurricane Sandy wondering how my house was the only one with power for ten days. I love being green and especially like having more green in the wallet.

 

[archimedes]

Speak for yourself! I've been using a home built whole house LED lighting system in my house for years:
THE BIANKA LOG BLOG: WATTS GOING DOWN ON LAND AND SEA
I actually came up with this idea from using LED's when living on the boat. I can walk through any room in my house without turning on a light from dusk to dawn. Really puzzled the neighbors after Hurricane Sandy wondering how my house was the only one with power for ten days. I love being green and especially like having more green in the wallet.

How did you resolve the separate wiring issue in your house?

 

[mbianka]

How did you resolve the separate wiring issue in your house?

I installed a separate DC wiring for the LED lights. Just simpler and cheaper with less hassle (Govt.) than grid tied systems IMO. Since the LED's draw so little current you don't need large large gauge wire. I used 12 AWG for the main run. Actually, the wire was left over Marine wiring from some boat projects. One light in each room provides plenty of light to move from one room to another. No real need to leave any other light on. The same two solar panels also power some 12 volt muffin fans that blow hot air from some home made solar hot air window boxes too. Though those are connected to the battery via separate fuses and separate wiring. They not hooked up via the solar controller that controls the lights.

 

[archimedes]

Interesting. So I guess you just ran the wires through the attic space?

 

[RichH]

Suggest you carefully look at your local existing wiring codes vs. 12vdc.
In most places if youre not 'up to code' you may be in for BIG surprise ... and if you have a fire when not fully code compliant, your Insurance underwriter may tell you to 'go take a hike'.

Functionally, DC does not 'like' long runs of wiring.

 

[mbianka]

Interesting. So I guess you just ran the wires through the attic space?

Used some electric wall molding from Home Depot for some runs along wall. Also ran some wires in interior closets. Though did run one wire through the ceiling into the dining room overhead LED light. Also recently added door activated switch for some interior locations not often accessed (i.e. laundry room) saving even more energy. Also have a switched light in the bedroom (for sleeping). Though most rooms are always lit. Been called by a number of those solar companies who tell me they can save me money by installing solar panels on the roof. I laugh when I tell them how much my electric bill is each month and they admit they can't really save me money since it is so low already.

 

[ccriders]

AC/DC houses are going to be common in the future. Things like lights, fans and appliance motors can be more efficient (and quieter in the case of motors). Air conditioners will continue to be AC until locally produced DC can be ramped up. Most good quality LED lighting is more expensive because it has to be plugged into AC necessitating built in transformers.
My father built a DC house twenty years ago and used rectified DC for uniquely AC requirements. Every room had one AC outlet. He converted all of his appliances to DC. He started with a propane refrigerator but canned that for a converted electric one.
His battery bank in the basement was a set of glass cased cells recycled from a telephone exchange. He had two 4X8 panels on a servo that kept them pointed at the sun. As I remember he modified a tracker for a telescope for his array.
He did all of this with his 50 year old high school education and was so far out in the woods he didn't worry about city codes, just used common sense wiring practices. Insurance? That's another thing he left behind in the city.
It can be done and there will be more of it when people realize they can continue to operate even when the electric company fails them and sell back their excess electricity.
John

 

[travellerw]

Frankly, I respectfully disagree with a bunch of these posts.

I believe the odds of utility companies offering DC anytime in the next 100 years is %0.

At least here, low voltage wiring is still subject to code requirements. I'm also guessing that %90 of people would never accept any retrofitted wire ran along wall or in closets, even in a proper wiring chase. Aesthetics matter to most people.

I have pulled my fair share of wire (used to help a journeyman electrician). I can tell you, in a modern finished house there is no way you could simply pull new wire to the existing fixtures. There is simply no direct run back to the electrical panel. Over %50 of the time, a light will be a leg off of a plug run with a finished wall and roof in between. Anyway, if you don't believe me, then it sounds like you have a million dollar idea and should start up a company to prove me wrong.

For me, I will simply take the %15 loss and pay the %20 premium for LEDs with built in AC drivers. I switched my house to CFL and LEDs about 2 years ago. Although my power bill dropped, it was only like %7. Lights were a small portion of our power draw. Now, if my wife would give up the dryer, then I could really save some green (well blue, purple, green, red and brown here in Canada)

 

[UnionPacific]

Functionally, DC does not 'like' long runs of wiring.

Only if power draw is high. With a light drawing 0.2 amps it likes it just fine.
Besides 24 volts is available too.

 

[UnionPacific]

I have pulled my fair share of wire (used to help a journeyman electrician). I can tell you, in a modern finished house there is no way you could simply pull new wire to the existing fixtures. There is simply no direct run back to the electrical panel.

Its a simple drillbit thru the floor joist, into the wall, pulled from an existing switch hole, then you use the existing wire up to the light. Not rocket science. You can keep the wiring in the basement. Maybe in Canada all basements are finished?

 

[mbianka]

I agree with you about the utility companies will not be offering DC service. That's why I did it myself. Plus it's easy enough to remove the wiring if I ever need too. There is no need to wire up to any switches as the lights come on at dusk and turn off at dawn. They provide enough light to walk anywhere in the House. I have not touched the original house wiring or electrical panel. Every time you turn on a grid tied light money starts flowing out of your wallet whether you are in the room or not. I just stopped that flow for several years now. Very happy I did. But, it was my boat living that showed me how to be more self sufficient with the time I spend on land. I keep expanding and modifying it and solar heating options and without relying on any subsidies from the government too.

Frankly, I respectfully disagree with a bunch of these posts.

I believe the odds of utility companies offering DC anytime in the next 100 years is %0.

At least here, low voltage wiring is still subject to code requirements. I'm also guessing that %90 of people would never accept any retrofitted wire ran along wall or in closets, even in a proper wiring chase. Aesthetics matter to most people.

I have pulled my fair share of wire (used to help a journeyman electrician). I can tell you, in a modern finished house there is no way you could simply pull new wire to the existing fixtures. There is simply no direct run back to the electrical panel. Over %50 of the time, a light will be a leg off of a plug run with a finished wall and roof in between. Anyway, if you don't believe me, then it sounds like you have a million dollar idea and should start up a company to prove me wrong.

For me, I will simply take the %15 loss and pay the %20 premium for LEDs with built in AC drivers. I switched my house to CFL and LEDs about 2 years ago. Although my power bill dropped, it was only like %7. Lights were a small portion of our power draw. Now, if my wife would give up the dryer, then I could really save some green (well blue, purple, green, red and brown here in Canada)