On Oct 20, 1:08*pm, T i m wrote:
Hi All,

I would like to put some solar powered lights in the 20' x 10' x 8'
(to eaves) *workshop, mainly just to be able to see in there to move
about rather than work as such. I don't have power down there all the
time atm (long story) and even if I did (and in the spirit of d_i_y) I
still like the idea of 1) making use of some of this kit [1] and 2)
having some alternative lighting in there.

So, I don't mind having a few unit, say one on each of the 5 roof
trusses and a pull switch by the door to turn them on and off but what
is currently the most efficient and good vfm please, LED or CF /
Fluro?

CFL is most efficient, then linear fl. LEDs vary - theyre most useful
for very low light output devices, eg 1w. Ideal for low power drop
lights due to robustness.


12V inverted up to ~600V or regulated down to 5 etc?

Every change of voltage loses energy, so 12v will be most efficienct.


I was thinking those tubular 12V x 8W fluro inspection lamps
(typically a fiver) or LED equiv held under the beams by a couple of
Terry clips each (as that way they could be easily pulled down to
replace the lamp (fluro)) or to help me see in a dark corner). They
also have clear outers (not 'diffusers') and even a built in reflector
so I can get most of the light out and where I want it and being
designed for 'inspection' would probably take a knock or two without
damage. *If I leave some slack cable on them they could be temporarily
re-positioned making use of the hook you often see on the ends of such
things?

I'd probably use a couple of those for ceiling lights, and a droplight
or 2, maybe LED.


http://www.machinemart.co.uk/images/...large/0231.jpg

Re the fluorescent, are there good and no_so_good, from an efficiency
pov please?

there is significant variation. Very thin tube CFLs are some of the
best.

Does spending more money generally mean I get a better
design (from a Lumens pov and ignoring the same unit priced higher
etc).

Tesco microspirals are efficient and cheap. High CCT lamps are
slightly more efficient, but the light quality's nasty.


I did think of using a maintained lamp unit but they would be more
expensive and I don't necessarily want them on when the power is off
(and I don't think they would be easy to switch etc).

Any ideas welcomed. ;-)

Cheers, *T i m

p.s. I guess I could use an inverter to run the existing 6' fluros off
a solar / mains charged battery but that might make the whole project
that much bigger and I'm not sure how efficient it would all be? This
all started from seeing one of those 15 quid solar shed lights! ;-)

[1] I have various solar panels (@~5W), can probably find an ex backup
type battery or two and have some suitable cable, so it's just the
actual lighting units I need.

While you could run a 5 footer at 240v, it would take a real long time
to replenish the energy used at just 5w. Energy capture can be
improved a little with diffuse reflection in winter only - dont
concentrate in summer.

One option would be to run the 5 footer at much reduced power. Details
depend on the ballast type, but either way its easy to do. Tube life
would drop signifcantly, but tubes are so cheap and other methods not
so, so it may work well.

TBH though I'd not overlook gas lighting. Its way more reliable than
solar electric, needs no installation, gives sensible output levels.


NT