LED globes / Electricity Cost

Dolby

Dolby

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I'm trying to work out the cost of an LED - only cost and not light quality

Right now my study is 40w x 2 (80w total) and I use this 3 hours a night (90 hrs per month). If they charge R1 per kwh - how do I work out how much these clobes are costing? If the LEDs are 5w x 2 (10w) - I'm curious to see whether the difference is visible at all.

What is a standard energy saver - around 20w?
 
if you leave your study light as is on for 1 our it will be 80wh, for 10 hours 800wh around 12 will be 1kwh for which you have to pay R1. The LED's you will have to put on 100hours to get to 1kwh
 
Multiply the wattage by the operating hours to get watt-hours. Divide by 1000 to get kwh.
The cfl energy savers are normally in the 10-15 Watt range
 
... so not even R8pm?

I hoped for a larger change tbh ;)

EDIT : Though I guess with the other rooms you can be looking at R40-R50pm saving
 
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The only problem is the price of the LED lamps. It is a huge cost upfront and it would take years to recoup the money.
If the price is R150 then you would need to save 150 kw/hr to break even.
Just convert all lamps to cfl and you will save some money.
Turn off all unused lights in the house
 
The ones that replace down lighters are generally R50.00 each (http://www.guzzle.co.za/specials/view/548193/)

I passed a store yesterday selling the spotlight types that I need for R70.00 each. If I end up buying 10 at R700.00 and save R50.00pm that'll be just over a year. It's not too bad I guess. Plus the ones I have now (standard) keep blowing and it's R20.00 or so every so often.

I guess on average break even would be a year
 
Fuzzbox said:
The only problem is the price of the LED lamps. It is a huge cost upfront and it would take years to recoup the money.
If the price is R150 then you would need to save 150 kw/hr to break even.
Just convert all lamps to cfl and you will save some money.
Turn off all unused lights in the house
Click to expand...

Made my costs on leds back on two months. I went with the samsung and phillips candle ones (R100-R150 p/candle) swapping out the existing 12-14 watts...
 
Fuzzbox said:
The only problem is the price of the LED lamps. It is a huge cost upfront and it would take years to recoup the money.
If the price is R150 then you would need to save 150 kw/hr to break even.
Just convert all lamps to cfl and you will save some money.
Turn off all unused lights in the house
Click to expand...

Don't forget that LEDs have a lifespan about 5 times longer than CFLs.
 
The error in most cost calculations is they ignore the capital cost of the incandescent light bulb yet include it for the other, so comparisons don't tell the whole story. For a real comparison, compare capital and running costs over the same period, say five or ten years.

Also, if it suits your budget, replace blown incandescents with LED or other low-power-draw lighting. No need to take out a working glowing filament if you don't want to, though it costs more to run per useful photon.
 
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Dolby said:
... so not even R8pm?

I hoped for a larger change tbh ;)

EDIT : Though I guess with the other rooms you can be looking at R40-R50pm saving
Click to expand...

Looking at the whole house makes a huge difference as i discovered.
It took me over a year of slowly working through my house from room to room but it has made a difference.

Had:
3 Bedrooms , Kitchen and Pantry/scullery - 2 spot overhead light fittings each with 14w Energy savers
- 5 x 28 = 140w
Open plan Lounge/Dining room and passage - 19 Downlighters - 19 x 12v 50w halogen = 950w
Toilet - 1 x 14w
Bathroom -1 x 14w
On suite - 1 x 14 w

Total W - 1132

Now:
3 Bedrooms, Kitchen and Pantry/scullery - 3 spot fittings - 3W LED's - 5 x 9 = 45w
19 Downlighters - 19 x 12v 3w = 57w (Had 1w in all but found them just too dim)
Toilet - 1 x 3w
Bathroom 2 x 3w downlighters
On suite - 2 x 3w downlighters

Total W - 117 -reduced by almost a factor of 10

(with 1w downlighters total of 79w) - less than your study :D
 
Normal lights aren't usually the enemy when it comes to cost savings.

Downlighters are the real evil that chow power and replacing those with LED made a massive difference to us not only in power but in heat as well.
 
Those R50.00 bulbs only seemed to be the downlighter type - and the R60-R70 were only candle :/

However, I managed to get 2 x R80.00 bulbs at 4w each - so 8w for my study! And they're a warm glow and the light looks good too!

AS more standard bulbs blow, I'll replace with these. At R80.00 they're not too bad and as someone said, a standard bulb would cost R20-R30 anyhow
 
I did my whole house with LED last in 2012. Shipped in the bulbs from China.
Cost in China in 2012 was RMB15 per 3W E27, and E14 bulb (screw in type - E = Edison, 27 = 27mm, 14 = 14mm).

I've since updated to 5W and 7W ones in some area's, as 3W was a little optimistic!
This year the pricing is about the same, but the 5w and 7w ones have dropped to the 3W price point.

All in all, it cost me about R2000 to buy (@R6 or so I think to the RMB, now its way more sadly), and ship bulbs over. I went airfreight which was a bit unnecessary, but they're light, so it was ok, and airfreight is easier than sea freight paperwork wise.
I still have extra bulbs, as I ordered about 30% more than I needed to make sure I had spares.

I've had 2 or 3 failures out of the entire house over 2 years now, so its about the same failure rate as traditional bulbs. I blame some of that on Eskom though - power is on / off and voltages spike occasionally throughout the year (I also have monitoring equipment hooked up to check on that, as I installed solar panels last year)

Still, it worked out to be massively cheaper than buying locally. This year, not so much though, as the rand has dropped in value :(

If you have a light fixture with several bulbs on it totally makes sense.
eg I have a number of chandeliers with 8 bulbs on. At 40w a bulb, turning that on was 320W an hour.
With LED's, I got that down to 24W. The amount of light emitted is about the same also. Its really worth it to replace stuff like that, and downlighters (eg the ones in kitchens).

Work out what the major users of power are, and replace those first!

Some photos of the bulbs and stuff:

http://www.flickr.com/photos/sheedl/8112133628/in/photostream/
http://www.flickr.com/photos/sheedl/8112124595/in/photostream/

Entire shipment
http://www.flickr.com/photos/sheedl/8112128370/in/photostream/
 
I use 8w CFLs at my place, so cost wise per month is not much of a factor but rather cost per globe which is where LEDs are still too costly besides i don't see the advantage to be honest. I think the light output is the same vs power used?
 
I've been giving this a fair amount of thought...

It makes no sense to replace existing working lightbulbs with LED's, but I'm doing renovations at home so all new light fittings will get LEDs, and as older bulbs blow they will be replaced with LEDs
 
LED's are way more efficient than CCFL (horrible for the environment as they contain mercury) or Incandescent (traditional bulbs)

Typically a LED
3W replaces a 25w incandescent +-
6W replaces a 40w incandescent +-
10w replaces a 60w incandescent +-
15w replaces a 100w incandescent +-

(roughly from the top of my head, google for actual equivalents)

LED's come in different color temperatures also, usually white, yellow or reddish, depending what temp led's are used.
I usually get a mix of yellow and white led's.

Higher color temps are bluish, middle is whitish, and lower are yellow/red
This page has some details - http://www.seesmartled.com/kb/choosing_color_temperature/
 
lsheed_cn said:
LED's are way more efficient than CCFL (horrible for the environment as they contain mercury) or Incandescent (traditional bulbs)

Typically a LED
3W replaces a 25w incandescent +-
6W replaces a 40w incandescent +-
10w replaces a 60w incandescent +-
15w replaces a 100w incandescent +-

(roughly from the top of my head, google for actual equivalents)

LED's come in different color temperatures also, usually white, yellow or reddish, depending what temp led's are used.
I usually get a mix of yellow and white led's.

Higher color temps are bluish, middle is whitish, and lower are yellow/red
This page has some details - http://www.seesmartled.com/kb/choosing_color_temperature/
Click to expand...

Where does one get 10-15w LEDs?
 
krycor said:
I think the light output is the same vs power used?
Click to expand...
noxibox said:
LEDs are probably worse.
Click to expand...
Rubbish. The light output is far higher per unit of power used. If it weren't then we wouldn't be having this debate. The question is whether the improved light output per unit of power justifies the increase initial cost.

I've got a mixture of the two installed here & I've come to three conclusions:
1) LED placement matters in a serious way. You need to think long & hard as to where you're putting them. Def not something you can wing. e.g. In retrospect I'd like more LEDs in the kitchen above the counter I use for chopping veggies and stuff. Similarly I'd like more LEDs in the rooms I spend more time in.
2) CFLs are a piece of sht. Mostly because they burn out much sooner than promised. 100% of my frequently used CFL have burned out (Osram/Philips mix - by most accounts decent brands). No joke...100%+. Bathroom 1/1, Study 3/2 (on 2nd set), bedroom 2/2. Piece of sht. Haven't lost a LED yet.
3) I'd like a high powered movable LED set. e.g. lying in bed an powerful LED downlighters is just no good. Kills the eyes while reading. Need to DIY a high powered LED standing lamp...
 
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