24v House

Anything to do with environmental building projects.
User avatar
Bulworthyproject
Barbara Good
Barbara Good
Posts: 109
Joined: Sun Jun 26, 2011 1:38 pm
Location: Rackenford, Devon
Contact:

24v House

Post: #273435 Bulworthyproject
Sun Apr 21, 2013 3:59 pm

Until a couple of days ago we planned to make the electrics of our off grid house 12v (dc).

There are some downsides compared with 240v (ac):
Most people use 240v (ac) so there are more appliances available for 240v (ac)
The amperage is higher so the cables have to be thicker (therefore more expensive)
Running high wattage appliances on 12v is not as practical (due to high amps)

However:
A lot of mobile appliances are available in 12v to plug into cars and these tend to be more energy efficient.
You do not lose efficiency converting dc (from solar) into ac (through an inverter) just to convert it back into dc as this is what most small appliances work on.
Our whole ethos prevents us from regularly using high wattage appliances.

Balancing this all up we decided to go for 12v (dc) until we looked into 24v (dc). The amperages are halved so the cable costs are lower, as are regulator costs. Other than that it is the same as 12v except for the availability of appliances. Lorry drivers use 24v appliances so there is a market out there but it is not as large as that for 12v stuff.

Does anyone have any experience of 24v systems, the availability of appliances and any other issues?
http://www.bulworthyproject.org.uk/events.html

Bulworthy Project is an experiment in low-impact living and working

Follow us on Twitter @bulworthy

User avatar
Thurston Garden
A selfsufficientish Regular
A selfsufficientish Regular
Posts: 1455
Joined: Fri May 25, 2007 3:19 pm
Location: Scottish Borders
Contact:

Re: 24v House

Post: #273458 Thurston Garden
Mon Apr 22, 2013 2:01 pm

I don't have any experience really but will be interested to watch this thread. I seriously considered no grid tie when I built the straw hoose and keeping it 12v but I was talked around following a few threads and discussions on the Navitron forum. The thought on there was that £3k for my grid tie was not expensive (contrary to my thinking!) and to tie. I did, and I am not sure if I made the correct choice.

My consumption is small 0.6kWh a day although this did rise when I bought a wee freezer. I think if I had the chance again, I would probably not have had the tie.
Thurston Garden.

http://www.thurstongarden.wordpress.com
Greenbelt is a Tory Policy and the Labour Party intends to build on it. (John Prescott)

User avatar
Bulworthyproject
Barbara Good
Barbara Good
Posts: 109
Joined: Sun Jun 26, 2011 1:38 pm
Location: Rackenford, Devon
Contact:

Re: 24v House

Post: #273472 Bulworthyproject
Tue Apr 23, 2013 11:56 am

We're a bit far from the mains for grid-tie ti be practical and there is definitely something about a self contained system that makes you think about energy use. In a lot of situations grid-tie is the sensible option though.

0.6kwh per day is pretty good.
http://www.bulworthyproject.org.uk/events.html

Bulworthy Project is an experiment in low-impact living and working

Follow us on Twitter @bulworthy

User avatar
diggernotdreamer
Site Admin
Site Admin
Posts: 1769
Joined: Sat Jun 30, 2012 10:23 pm
Location: North West Ireland

Re: 24v House

Post: #273473 diggernotdreamer
Tue Apr 23, 2013 1:01 pm

How do you use so little electricity, try as we might, we cannot get our electricity useage down lower than about average 18kw a day

User avatar
Thurston Garden
A selfsufficientish Regular
A selfsufficientish Regular
Posts: 1455
Joined: Fri May 25, 2007 3:19 pm
Location: Scottish Borders
Contact:

Re: 24v House

Post: #273475 Thurston Garden
Tue Apr 23, 2013 4:30 pm

diggernotdreamer wrote:18kw a day
:shock:

There's only me in the house. No dishwasher, no TV, only an A rated wee fridge, a mac mini and an amplifier on in the evening. One of the key things for me is I will make bread or do my washing when the sun is out so I am using my own electricity. My average consumption has definitely gone up now I have a freezer. Even at that, it's not near 1.8 neverheed 18. Are you sure next door don't have a secret cable connected to your supply :icon_smile:
Thurston Garden.



http://www.thurstongarden.wordpress.com

Greenbelt is a Tory Policy and the Labour Party intends to build on it. (John Prescott)

User avatar
Bulworthyproject
Barbara Good
Barbara Good
Posts: 109
Joined: Sun Jun 26, 2011 1:38 pm
Location: Rackenford, Devon
Contact:

Re: 24v House

Post: #273476 Bulworthyproject
Tue Apr 23, 2013 5:03 pm

Having lived 4 years in two caravans stuck together with 120w of solar panel, we dream of having 0.6kwh a day of electric. Previously when we lived in houses goodness only knows how much we used.

Not having a tv definitely helps. (not just with power consumption)
http://www.bulworthyproject.org.uk/events.html

Bulworthy Project is an experiment in low-impact living and working

Follow us on Twitter @bulworthy

User avatar
Thurston Garden
A selfsufficientish Regular
A selfsufficientish Regular
Posts: 1455
Joined: Fri May 25, 2007 3:19 pm
Location: Scottish Borders
Contact:

Re: 24v House

Post: #273478 Thurston Garden
Tue Apr 23, 2013 5:07 pm

Bulworthyproject wrote:Having lived 4 years in two caravans stuck together with 120w of solar panel, we dream of having 0.6kwh a day of electric. Previously when we lived in houses goodness only knows how much we used.

Not having a tv definitely helps. (not just with power consumption)


Being Scottish and miserable helps me!
Thurston Garden.



http://www.thurstongarden.wordpress.com

Greenbelt is a Tory Policy and the Labour Party intends to build on it. (John Prescott)

User avatar
diggernotdreamer
Site Admin
Site Admin
Posts: 1769
Joined: Sat Jun 30, 2012 10:23 pm
Location: North West Ireland

Re: 24v House

Post: #273480 diggernotdreamer
Tue Apr 23, 2013 8:31 pm

Are you sure next door don't have a secret cable connected to your supply

Hah, we did wonder that. We spent several weeks logging our useage. Then we turned everything off until the wheel stopped, so unfortunately, it is us that is using it. We have a fridge freezer, and we do watch telly in the evening, it all seems to add up, oh and the wizard is an engineer so we often have lights on in the workshop and he might run some machines if he gets a bit of work, we have the immersion on all the time, we found it was actually cheaper to leave it on then put it on when we wanted showers, and at the end of the day, we would have to boil kettles of water to wash up, so I guess we just have to grin and bear it, we don't waste it either

woodi
margo - newbie
margo - newbie
Posts: 5
Joined: Sun Aug 05, 2012 8:41 pm
latitude: 47.73855
longitude: 12.508828
Location: Ballyroney, Northern Ireland

Re: 24v House

Post: #273776 woodi
Tue May 07, 2013 7:47 pm

Hi - we lived for a long time in a truck, using 12v electrics powered by solar and wind. We've now moved about 10 feet away into a cottage that we were going to wire for 24volt, but eventually decided on 240v.
Here's why.
12 or 24 volt means you're carrying fairly high currents and so need heavier cable. It is also harder to find good durable sockets etc for 12 or 24v gear. Also you will need to rewire if you ever change your minds.
We plumped for wiring for 240v, using LED bulbs throughout. Our power comes in from only 500W of solar, through a couple of victron charge controllers, and into a pure sine inverter. Losses really are minimal, and we just use appliances sensibly. It runs all the lights in a 1 bedroom cottage, our fridge, a laptop and router. We've 500Ah of AGM batteries, and we don't make any significant dent in their state of charge.
Low voltage is grand if you have short cable runs and 12v appliances, but don't discount inverters and 240v.
cheers
Steve


Return to “Green Building”

Who is online

Users browsing this forum: No registered users and 3 guests