Domestic Low Voltage DC Supply

It would work, in principle, though to supply a stated power at low voltages would require greater currents to be drawn than on mains voltages, and the wiring may be insufficient cross-section to accomodate it, resulting in significant voltage drops where one doesn't have many volts to play with. For example, a 6A lighting circuit will only handle a maximum of 72W at 12V before the breaker starts wanting to trip. If up to 72W is all that is wanted, and one was prepared to tolerate a loss of a significant part of that in the wiring, then fine.

Otherwise, heavier cable is required than may be found ordinarily on a domestic 6A lighting circuit, as typified in marine and caravan/trailer applications. As a recommendation, try "The 12V Handbook" on internet booksellers as a good start. MAny dual-voltage systems use different plugs and sockets for appliances to reduce the risk of damage to their being connected to the wrong supply; the 'old' domestic 5A plugs and sockets are still available and often used by the marine fraternity on 12V, for example.

Yes in theory it is a good idea, but this would have to be driven by manufacturers who would have to supply a suitable range of equipment which people want, and therefore would force them to spend substantial sums of money converting their electrical installations.

The sort of system you mention has already been, and declined, in industrial applications mainly for safety reasons, where 240v, 110v, and 25v ring main circuits could be found in an installation using BS196 sockets and plugs originally, and later the BS4343 type connectors.

Unfortunately modern designers tend to incorrectly rely upon RCD protection for installations and the above applications are never seen now.

Applying these applications to domestic environments will be costly. 12v or v24v DC wiring requires a different colour coding under BS 7671 and therefore existing cabling cannot be used. Conductor sizes have to be increased with the respective high cost

In the UK this will become a major issue with introduction ofter new Home Owners Information Pack for house buyers, which will require the seller to provide a verification certificate of the electrical installation in the house. Verification and certification of electrical installations was introduced in the 15th edition of the IEE regs in 1984. How many people in the UK reading this post can say they have a valid electrical installation certificate for all works completed after 1984. It is anticipated that 96% of houses for sale in the UK will require substantial work or complete rewiring to gain a valid electrical installation certificate.

This is one of the reasons why the home information pack introduction has been delayed so many times.

So cost and availability of electrical equipment and appliances, and substantial installation costs are likely to be a major disadvantage for this proposal.

It is much better to leave the installation as it is at 240V and use any external LV supply converted to 240v.

12v and 24v - 240 inverters are becoming more popular and cheaper now and it is much easier to step up power supplies.

Why try to re-invent the wheel when you already have the the spokes, the rim, and the tyre.

You should need extra outlets (for d.c. and a.c.), extra wiring, thicker wires...

As the a.c. is the standard you can't have electrical set up for your house only for the d.c.... The d.c. could be an option in the case you would like to use wind generators or sollar cells... Even if you built your own house for the use of, only, d.c. voltage (customised house) you should convert the a.c. of the network to d.c. (in order to be compatible with the d.c. voltage of your e.g. solar cells and have redundancy of energy for safety reasons)... This means extra and expensive equipment...

Another reason is that the comercial manufacturers should produce the same products for use with d.c. or a.c. (e.g. a TV that operates with 12V or 24V d.c. and another T.V. that operates with 220V a.c.) and this means two different versions of a product, two product lines e.t.c....That's hard... Also, these "d.c. products" should be more expensive because the comercial demand would be small, as only few consumers would use d.c. voltage to supply their domestic devices...

In the early days of electrification in New York, the original DC supply would not reach the top of the taller buildings. AC was adopted because less power was lost in transmission -but losses are still an important consideration of why local generation is now being promoted.

But the story continues at the turn of the 20th century, of the conviction of a circus elephant, subsequently sentenced to death by electrocution for killing its keeper.

Unfortunately the new AC system was used and the poor animal suffered greatly as the AC current flowed around it's body rather than through its body -with an intent to stop its heart scientifically.

Interestingly, the USA has a 60Hz AC supply, the UK a 50Hz AC supply.

DC even at low voltages is potentially LETHAL, be very afraid! Storage of useful quantities of DC current for domestic purposes will expose you to this danger. DIY enthusiasm is all well and good, but the technology has many aspects which need to be fully appreciated to reduce the dangers of explosion, fire, chemical burns, toxic pollution and wake.

The Marine environment uses generator to produce 220v and then inverters or simply a battery charger to extract the 12v or 24v supply for instruments,lighting or any other usage. Any dual system gets complicated but take a 12v LED light that has a 110v converter and wire it direct and your light is happy. But what I would like explained is why some of the older boats had 32v systems and not 24v or 36v.

I'll ask my grandfather - he was Chief Engineer on the Marie Celeste.