I want to buy a (300/500W halogen equivalent intensity) low energy
floodlight for my drive.
But I'm not convinced how bright it will be.
I've also found:
Just the ticket but I would prefer white not sodium orange.
Any product/supplier suggestions sub - £100? What lamp technology should I
be looking for?
To OP, good news, your screwfix link is to a high pressure sodium fitting
with is not the bad old sodium orange but more a golden white (quote from
lamp data). BUT, IIRC they have a warmup time & don't restart
immediately when hot . . . . or have I mixed it up with another system?
Because it's only 12 volts at 20 or 50 or 100 watts on each lamp, so the
power supply unit is very small and costs very, very little to run. For an
output of 60 watts of low voltage lighting, the equivalent running cost of a
power supply unit is as little as 20 watts, so it doesn't take a lot of
brain cells to work out the maths there. It's the reflector size and shape
which creates a bright floodlighting effect. And I for one, would rather
run a decent low voltage lighting system, than a bloody great 300 watt
tungsten halogen, that you can almost sunbathe under. The low voltage
system can also be connected through a cheap PIR detector with a small
relay, to switch the lighting on when something triggers it, so that can
also be set into the equation. When the lamps are off, a decent PSU also,
quite literally, runs at a very negligible cost.
If you ask the owners of the three builders yards where this type of system
is installed, I think they'll tell you that the old halogen lamps cost about
three times the amount than the new 12 volts systems they now have. They
tried many different styles and methods of lighting their yards, and all
were costing them a small fortune because they are left on all day, every
So we asked them if they wanted to try a 12 volts system for a trial period,
just to see if it would help bring the bills down a bit, and they accepted.
Our proposal was the supply and installation of a low voltage lighting
system at no cost to them for the duration of the test period, and the only
thing they had to pay for was the power to make everything work. A bit of
an offer they couldn't refuse. The deal was, we would leave the existing
lighting in place, to be reinstated if our system failed to meet
expectations, and all they would be paying for during the test was the
We fitted a meter to the existing lighting supply circuit and separated it
from the rest of the building, and a reading was taken at the beginning of
the proposed three months test of the old system, and it was left to do its
thing. We then swapped the same supply over to the newly installed 12 volts
systems and again, a reading was taken from the meter and the next three
months test with the new system began.
To see their surprise when the new 12 volts systems came in at under a third
of the running costs of their old halogen lighting, and having had nothing
but good reports from the fleet drivers who used the yards at all hours of
the day (hence it having to be left on all the time), they promptly asked us
to go ahead and install another two systems in their satellite depots and
they had no problem paying us for them, as they would recoupe the
installation cost from the savings they made, in a little over two years.
And the lamps themselves are cheaper and easier to replace in the fittings,
which was also of great benefit.
They also use portable dual input voltage (110 - 240), emergency lighting
systems which we supplied for them to use on their building site cabins and
things. They liked the idea of having lights in prime areas (site offices,
stairwells, and loos mainly) that stayed on for a couple of hours or so even
if the rest of the power to the site was cut. It allows them to carry on
with paperwork and meetings, which is very common on sites, as you'll know.
So yes, I would recommend the use of this type of lighting around the house
as well. For convenience and running cost, they are hard to beat. And
whether it says 100 or 1000 watts, then it can't be any dimmer or brighter
than any other 100 or 1000 watts. Can it ?
1000 Watts at 12V uses the same amount of electricity as 1000W at any other
In fact, it will use slightly more electricity to run a 1000w 12v bulb as
there is a loss at the transformer (they get hot!)
If you were talking about Amps, then it is different - 1Amp at 12v is a lot
less than 1Amp at 240Volts
With Watts it is all the same
If you can achieve less total wattage with low voltage lights, then of
course there will be a saving - but lower voltage requires thicker (more
expensive) cable, and is a lot more prone to voltage drop
I think I got the drift after the longer explanation (the first one was greek to
me) - think it's something about distributed light being more effective than a
single point source so you can get away with a less total power. Almost
makes sense :-)
I confess I find the thought of my garage gable-end being festooned with
miscellaneous automotive lamps rather appealing. Kind of a Mod retro thing.
500Watts at 12 volts? 40+ Amps? You'd be able to smell if the wiring's not
up to it!
Not sure the Bravo Alpha Charlie will approve.
I'm utterly unconvinced about the "power" argument though.....the goal is a
nett reduction in Erg-usage.
Thinking aloud...a bank of car batteries, a yacht wind generator, some
photovoltaics for good measure....perhaps the electricity bill could be
reduced to zero.
1,000 joules of electrical energy per second.
Anyway different kinds of lamps have different efficencies in turning
electrical energy into visible light. A 50W lamp of the most efficent
kind will give off about as much light as a 1,000W lamp of the least
Its rare that I'd disagree with Bigwallop, but I think I will on this
one. AFAICS your power savings appear to have come from
a) photocell operation, and
b) lower total lighting wattage
It is also true that LV halogens are a bit more efficient than mains
ones, but the setup cost is somewhat higher too.
I think CFLS are cheaper.
its between 60 and 70w. There are no 300% efficient power supplise.
As do 150w, 300w 500w and 1kW halogs. The larger size of the car
headlamp reflectors acts to provide a narrower central light beam, and
is not usually of any advantage for yard lighting.
yup, thats the issue, the lower power. You could of course use a 150w
halogen instead of a 300. Its only when you need much lower powers
than that that LV wins, simply because low power mains halogs are not
In fact all controllers will work with mains halogens, but only some
will work with LV systems.
and mains runs at zero cost.
Yes, that is a real plus in some locations. For home lighting tho,
battery backup systems arent normally installed.
they're beaten by fluorsecent and CFL, or, if you dont mind odd
colours, they're thrashed royally by sodium and mercury lights.
yes, there is a wide difference in efficiency of different types of
I think you made the right choice, because of the want for battery
backup, and the division of the lighting into separately controlled
[low power] areas. But for home use the picture is quite different.
With a lamp of the same characteristics it will always take more
energy to use a 12V lamp and a transformer than a 230V lamp.
Transformers are not 100% efficent devices.
The power rating of a lamp simply reflects its consumption of electrical
power. A lamp's output of visible light is generally measured in lumens
or lumens per watt.
There is a nice table at http://www.lightswitch.co.uk/help/lpw.htm
The most efficent is low pressure sodium, typically used for
That table doesn't, though, give lumens-per-watt figures for 240V
mains halogens of non-linear construction (GU10-type fittings), nor
for 12V reflector halogens. It's been asserted repeatedly here that
the thicker filaments of the 12V result in more light-per-electrical-watt
than the weedy she-cannae-take-it filaments of 240V halogens; so that's
a factor you have to balance against the inevitable, but possibly modest,
losses in going down from 240V to 12V by either pure-induction transformer
or the magick which is a switched-mode PSU (called an "electronic
transformer" in the electrickal trade).
One has to ask why you want the level of light on your drive? All it
does is make the darkness beyound the the reach of the light appear
even darker and you don't stand a chnace of developing any night
vision. Oh and don't forget the light pollution.
The only thing I can think of that would require that level of light
is working out there but you'd be far better off with a lower level
general light, couple of bulkhead, sheilded/reflected so light does
not go upwards at all with 60W bulbs and then have portable light
source to illuminate the immediate work area. This has a few
advantages for the working point of view as well as reducing much of
my adverse comments above. You don't have dark shadows in the work
area anymore as you have light coming from more than one direction at
a lower but more even level. You can move the work light around so
that you illuminate exactly what you want not just where the light
happens to fall.
Dave. pam is missing e-mail
I live in a dark place, where dark pollution is a big problem :-) The
nearest street light is 200 metres away.
The problem is that my children's desire to skateboard and rollerblade after
school is undiminished in the winter and I get fed up with 500W lamps being
casually switched on and forgotten all the time. I also disapprove of
We're talking about a 1/2 tennis court sort of area.
I therefore intend to install an energy efficient floodlight turning on (via
photocell) at dusk and going off on a timer later.
You don't know what dark is with a street light that close. Nearest
one to us is 1 1/2 miles away. B-)
Not that big, but I agree that something more than a couple of
bulkheads with ordnary 60W bulbs is required. Without knowing where
you can fix lights I really do think you'd be better off going for a
number of smaller lamps each covering an overlapping section of the
ground. If you can get the fittings CFL would be good from the lecky
I want some reasonable external lighting here, it's dangerous outside
on a cloudy moonless night there simply isn't *any* light. You
literally can't see the end of your nose, to give you an idea
headlights from cars on a road 4 miles away can look like someone
playing a torch on the house. Ring (OK I know) do a nice looking 75W
halogen cast Ali lamp, damned if I can remember the name (Aristo?) in
single and double head versions. These are designed with minimising
light pollution, unlike the £3.99 500W flood light...
Dave. pam is missing e-mail
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.