Home: Electricity
Solar-powered low-voltage lighting   (+3, -2)  [vote for, against]
Nobody's thought of this yet? Seriously?

Many consumers are now choosing to install exterior accent lighting that runs off of a 12-volt transformer plugged into an outdoor outlet, rather than the much more complex (read: dangerous to idiots like me) 120-volt lighting that was standard for the previous 50 years or so.

Low-voltage lighting is a lot like track lighting for your sidewalk: stick the lights where you want 'em, clip them to the self-sealing copper lead (which can be buried as shallow as you like), and plug that into the wall. Ta-da.

As a bonus, if you get bored with one style of lamp, it's an easy job to replace them with a new fashion. Change them for the seasons, even.

Sucks if you don't have exterior outlets, though.

So, for those who don't have exterior outlets or want to light an area far from power sources, there's always solar accent lighting. It's a little more expensive up front, but much simpler - just jam the sucker into the dirt, wait for Helios to pull his chariot, and that night, light. Ta-da.

Problem is that if your house is close to another, this'll never work.

Now, there are some solar kits that have a remote solar panel, but these consist of at most 4 lights and are not interchangable with other brands or styles. Once you have one remote-panel kit, you're stuck with it.

So why not combine the two? Simply marry a solar panel to a 12-volt rechargable battery pack and photocell, run the low-voltage wiring, and darkness begone! (for up to 8 hours, results may vary, eat your vegetables).

By using this system, the homeowner can utilize any of his/her preferred models of low-voltage lamps, and still take advantage of the long-term cost savings and feelgoodness of solar lighting.
-- shapu, Mar 26 2007

http://www.solarilluminations.com/ Like the floodlight in the center of the second row? [jutta, Mar 26 2007]

Solar 12v rechargable lighting kit. http://www.selectso...ics/shedmatekit.php
Bring Your Own Battery. [jutta, Mar 26 2007]

How-To, system details http://www.backwood...ticles2/yago92.html
[jutta, Mar 26 2007]

Solar Powered Garden Lamp http://mysolarshop.com/pro519762.html
This, No? [gnomethang, Mar 26 2007]

So, what's new about this is that you've moved the solar panel away from the garden fixture, rather than it being directly attached?
-- jutta, Mar 26 2007

What's new is that this is interchangable with any other 12-v outdoor lamp - current solar kits are either attached to the lamp (as you pointed out) or have 3 or 4 lamps that are not compatible with any other brand. This is a universal power source (should have made that clearer, I think).
-- shapu, Mar 26 2007

Hm. Hm! So the invention would consist of a box containing the following, readily available components: (a) a 12V battery; (b) a solar panel and cables to connect to (a); (c) various kinds of cabling to run the 12V somewhere in a garden; (d) a timer or photo switch?

[What does the standard 12V interface look like? I mean, I know the little halogen thingies hanging from two wires, but surely you'd want something more covered for outdoors?]
-- jutta, Mar 26 2007

Pretty much, yeah - preassembled for folks who, like myself, have a hard time plugging in the vacuum correctly. And low-key, if possible.

Answer to question two: The 12-v cable is a pretty simple beast. It doesn't require deep burial, unlike the 110 or 120, nor the boxes or conduit. Three or four inches is plenty deep, though you can put it deeper if you like. The current standard is a transformer that plugs into any outdoor outlet, which then runs a self-sealing lead out to the lights. The lights have a clip that breaks the seal around the lead.
-- shapu, Mar 26 2007

OK, thanks for explaining!
-- jutta, Mar 26 2007

I grok. I dig. But then I can see the homeowners association nabobs passing ordinances against solar panels standalones.
-- bungston, Mar 26 2007

Um... Am I missing something here?. I know countless households with solar powered lawn/path lights (Linky).
I naturally assumed that they were widely known to exist.
-- gnomethang, Mar 26 2007

Those folks are using independent, standalone solar lights. This is a system that allows you to strand normal 12-v lights and power them all from one remote solar cell, rather than an exterior outlet.
-- shapu, Mar 26 2007

Sorry, you are quite correct. I'm not sure how this scores over the stand alone variety, though.
-- gnomethang, Mar 28 2007

The primary advantage is that you can have the solar panel in a space that actually gets solar light, while the lamps need not be.

I wonder if I am far more (too?) emotionally involved in this idea than everyone else?
-- shapu, Mar 29 2007

Umm... solar powered low voltage lighting with the panels and the lights widely separated have been widely available for yachts and motor homes since the seventies.

Of course, those were interior lights...
-- ye_river_xiv, Mar 30 2007

I think the invention here is standardisation of components across diverse manufacturers. Makes sense. We standardise house lighting and wiring. How would it be if you could only get the right kind of light bulbs for your house from the company that installed the wiring?

I believe the current lack of standards is down to the fact that 12V isn't going to kill you, whereas 110-240V can.
-- BunsenHoneydew, Mar 31 2007

That sounds like a dare to me, [Bunsen].
-- shapu, Apr 01 2007

[Bunsen], granted it's not as common, but if you put enough amperage behind that 12V you'll end up just as dead as using 110-240V.

I think [shapu] has simply suggested combining existing products in a sensible manner, sort of like putting peanut butter inside a chocolate coating, so kudos for the common sense, but it's neither bun- nor bone-worthy.
-- Canuck, Apr 01 2007

//granted it's not as common, but if you put enough amperage behind that 12V you'll end up just as dead as using 110-240V.// How many amps? I've held the terminals of a bus battery, probably easily capable of a good 200 amps without even feeling warm. On the other hand, 240V bounced me across the room.
-- coprocephalous, Apr 01 2007

That would be down to the resistance of your body. Let's call it 24 ohms for convenience, although it's probably higher and varies according to conditions.

V=IR => I=V/R

at 12 volts:

I = 12/24
= 0.5 amps

at 240V (simplified to DC)

I = 240/24
= 10 amps

See the problem?
-- BunsenHoneydew, Apr 02 2007

//Let's call it 24 ohms for convenience// Let's call it 300kohm, for realism.
I=12/300000 = 40 microamps.
cf 150 microamps across the heart to cause fibrillation.
No [BH], I don't see the problem.
-- coprocephalous, Apr 02 2007

Great idea... I have already hooked up my dog's invisible fence to run off a solar/batt combination... works great. moving on to some lighting... it's hard to find a 12v photocell and how does one calculate the needed battery and solar requirements? I just guessed for the fence system and it worked out well.
-- jweaks, Aug 21 2007

without reading the annos...

Do you [shapu] realize the MASS AMOUNT of amperage your talking here?! The solar panels would be massive. I'm thinking at least 1m square for each lamp. LED solar lights work because LEDs are nothing compared to incadesent bulbs. This idea would work fine, If you covered your and your neighboors roof's with solar panels
-- evilpenguin, Aug 21 2007

[evilpenguin]: For a 12-volt system?

Self-sealing copper wire like this is limited by code to 192 watts, at 12 V.

P = VI, right? So I = P/V, or 12/192 = .0625 amps, or...uhm...6 times that necessary to cause a person to be unable to release a clenched hand.

Hmmm. So, no gripping the wires when you've recently cut yourself.

At any rate, many low-voltage systems are designed to work with LED lamps (presumably they have some sort of step-down system, yes?) And jutta's linked to someone who has presumably beaten me to the punch on this complete system. The system described has a much smaller panel than that which you're thinking of. Ergo, it's for all intents and purposes baked, or at least warmed over, so the point is moot.
-- shapu, Feb 09 2009

random, halfbakery