GU10 spotlights, power consumption and should I go LED?

baldelectrician

I was at a clients house last week and put in 13w CFL Gu10 lamps, they were brighter than the 50W GU10 lamps she had in

I have tried the GU10 LED lamps and they are not bright enough yet, they will get better in time

zax47

pault123 wrote: »

so based on this as my lights are alreadys 50w. thats 300w for six lights = which is 300/1000*15 = £4.50 an hour to light my kitchen? that doesn't seem right?

That calculation assumes £15 per kWh, not 15p. My calculation clearly shows 15p and gives an answer in pence, not pounds like yours!!

is a 0. decimal place missing from the above 15 p?

should the calc be 300/1000*0.15 = 0.045

x 2 hours a night = 0.09 x 30 days = £2.70 a month to light kitchen for 2 hours a night

Correct. 15p = £0.15.

and in above example of extra workings to upgrade from 35w to 50w in a kitchen of x6 the calc should read

90W/h = 0.15p/(1000/90) = 0.0135p

It already does show 15p which = £0.15, not 0.15p. Calculation and answer is correct, 1.35p per hour to add 90W of additional lighting. 1.35p which is 15p/(1000/90) or £0.15/(1000/90), but not 0.15p/(1000/90).

i've been trying to stop using my kitchen lights since reading this post, but then thought hold on those figures can't be right LOL

Figures are right, your interpretation was flawed.

allanhamer

We have a dark on suite small bathroom with no source of natural light. Was using some standard GU10 35w bulbs (there are 5 in the bathroom) which was leaving the bathroom a little darker than we wanted. Decided to look around for some GU10 LED equivalents (as the lights in the on-suite are used every day even during the day as well as night time) to keep down the power costs.

The bulbs we went for eventually were from lightplanet.co.uk the V3 7watt GU10s LED. They're equivalent to the normal GU10 halogen light wise and put out a nice warm light (we went for the Warm white 14565s), while expensive at £26 per light they have a good 120degree spead of light but if you really want a 50w halogen GU10 equivalent in an LED I really havent seen much better. No link between me and the company other than they providede a good service and some advice for which light type to go for.

Allan

pault123

zax47 wrote: »

That calculation assumes £15 per kWh, not 15p. My calculation clearly shows 15p and gives an answer in pence, not pounds like yours!!

Correct. 15p = £0.15.

It already does show 15p which = £0.15, not 0.15p. Calculation and answer is correct, 1.35p per hour to add 90W of additional lighting. 1.35p which is 15p/(1000/90) or £0.15/(1000/90), but not 0.15p/(1000/90).

Figures are right, your interpretation was flawed.

simple case of me reading a £ sign where there wasn't one! LOL added to the mention of whopping and the p on the end further cemented the £ sign as I read it :rotfl::rotfl:

thanks !

pault123

allanhamer wrote: »

We have a dark on suite small bathroom with no source of natural light. Was using some standard GU10 35w bulbs (there are 5 in the bathroom) which was leaving the bathroom a little darker than we wanted. Decided to look around for some GU10 LED equivalents (as the lights in the on-suite are used every day even during the day as well as night time) to keep down the power costs.

The bulbs we went for eventually were from lightplanet.co.uk the V3 7watt GU10s LED. They're equivalent to the normal GU10 halogen light wise and put out a nice warm light (we went for the Warm white 14565s), while expensive at £26 per light they have a good 120degree spead of light but if you really want a 50w halogen GU10 equivalent in an LED I really havent seen much better. No link between me and the company other than they providede a good service and some advice for which light type to go for.

Allan

i'll have to do some workings out on payback with lower energy lights i guess.

Seen the Phillips 2 year warranty 35 + 50w GU10's tonight in morrisons for £2.50 for x2.

So if I went for the 50w to keep the kitchen bright thats

£1.25 lamp cost and based on x6 lamps = 300w

300/1000*0.15 = 0.045 x 2 hours per night x 365 days per year = £32.85 yearly cost of kitchen light. + £1.25 x 6 (bulb cost) = £40.35


If i go for £26 lights

i make that 7watts x 6 lamps = 42w

42/1000*0.15 = 0.0063 x 2 hours per night x 365 days per year = £4.59 yearly cost of kitchen light + £26 x 6 (bulb cost) = £160.59

So about 4 years for return on investment.


I've yet to investigate the cheaper energy savers.

aboard_epsilon

Home bargains ..are selling 72 group of leds sort of mounted in a box...with batteries and on off switch..for about £3.99

they also have three quite good magnets on them so you could use them in a car under bonnet perhaps

for the slightly clever out there ..you could remount these ..transformer them ..and have a usable product .

Ive just tried one out ...and I'm quite impressed.

they are very bright ..but angle is small...from ceiling height ..they spread very intense light onto the floor about 6 feet in diameter ..with a less intense circle about 12 foot in diameter around it

so i would imagine my 10 foot x 10 kitchen being illuminated very well with four of the units

my workshop which uses 1000 watts of lights at the mo ..could be illuminated by 16 of them ..


i dont know if they are being overdriven though ,...and they may be short lived ..they do seem very very bright .

all the best.markj

Sye_2

7W high spot LED lamps give the same amount of light as a 50W halogen GU10. There are plenty of branded manufacturers around, do a search. They should cost around £25 - £28 each but will last for years.

Total cost recovery is just under 2 years at that price.

Stay clear of the cluster lamps. They are made from poor quality LED's and give a fraction of the light output watt for watt. In addition the small LED lamps fail quite quickly.

aboard_epsilon

Sye wrote: »

7W high spot LED lamps give the same amount of light as a 50W halogen GU10. There are plenty of branded manufacturers around, do a search. They should cost around £25 - £28 each but will last for years.

Total cost recovery is just under 2 years at that price.

Stay clear of the cluster lamps. They are made from poor quality LED's and give a fraction of the light output watt for watt. In addition the small LED lamps fail quite quickly.

deleted

correct me if im wrong .


£56 a year for one 50 watt left on 24/7

one 50 watt left on for 4 hours a day is £9.30 a year

3 years = £27...then you have minus the 7 watts .

so you are right if they were on for 6 hours ..i think

all the best.markj

Kaz2904

I bought some LED GU10's once. Never again. I have 5 lights in my kitchen and it was still too dark to cook anything. Dishes were always dirty too as we couldn't see to wash up. It was winter too (and I work nights!).
We got the fluorescent tube ones about £9 per bulb from B&Q. We have 2 and the rest are normal. I need lots of bulbs now and I'm going to just bite the bullet and get the expensive ones. Once the others blow, I'll get them too. It's a bit of an eek moment though!

aboard_epsilon

ebay brings up the 7 watters at £18.95 with free postage ..

http://cgi.ebay.co.uk/GU10-High-Power-7w-LED-Day-White-Spot-Light-50w-/270595736500?pt=UK_HomeGarden_Lighting_Lamps_Lighting_SM&hash=item3f00c343b4

same person also sells them in bulk with better discounts again ..

i have not had any dealings with this person ..so i cant recommend them ..or know nothing about the reliability of the lamps

all the best.markj

edit

utterly confuced here ...how can you tell good from bad ...these are 7 watt and cheap as chips

http://cgi.ebay.co.uk/GU10-LOW-ENERGY-SAVING-BULB-WARM-COOL-WHITE-LIGHT-7w-9w-/370395095747?pt=UK_Light_Bulbs&var=&hash=item95033cd70f

so ..competition time ..who can find the biggest bang for your bucks on ebay