Is a candle more energy-efficient than a lightbulb?

Question

Ok, so does a candle work out more environmentally-friendly than a lightbulb (let's say, a 60W incandescent)?

One thing to consider is that 2/3rds of power generated at a power plant is lost - from the lines - on the way to the consumer.

So for some ambient lighting, does the candle beat the light bulb?

GO!

Answer 1

Yeah, seems like the candle would be more efficient than a lightbulb. Efficiencies deal with input to output. You dont have to put much into a candle to get the light. Unless your considering the effort of manufacturing the actual candle.... Oh c**p! Now you got me thinking! Thanks alot!

Answer 2

the problem with incandescent bulbs is that 90% of the primary energy they consume is to make enough heat to make the wire filament glow.  this means as a light source they are only 10% efficient.  they are however great small heaters!

with a candle on the other hand the heat is a byproduct of making the light and not a require to make the light, so - as far as light goes - they are more efficient.  

the real comparison comes into play when you try to determine how many candles it would take to generate the same amount of light over the life expectancy of a bulb.

the best of both worlds would be compact florescent bulbs that produce as much light as an incandescent one but are more efficient because they don't need all the heat to make the light.  

the  only drawback to them is their mercury content, but they are recyclable so it would be a poor choice to throw them away in the trash, but than that's an answer to a different questions...

Answer 3

The lightbulb is more energy efficient.  It's complicated to explain why as it involves lots of things like luminous intensity, lux, lumens, steradians and stuff.

In simple terms, many candles are needed to produce the same amount of light that a single bulb gives off.  Almost all the energy from a candle is given off as heat - about 99% of it.  A standard lightbulb 'wastes' about 75% of the energy it consumes as heat - in respect of energy wasted the lightbulb is 25 times as efficient as the candle.

I'm sure if you looked it up there would be a site telling you how many candles = 1 light bulb, my guess (and it's only a guess) would be in the order of 50.

Reading up on luminance and the like is a good way to go to sleep, here's a couple of links...

http://en.wikipedia.org/wiki/Luminance

http://www.thesustainablevillage.com/ess...

Also, if a lightbulb lasts for say 1000 hours and a candle lasts for 5 hours you'd need to manufacture 10,000 candles per one lightbulb so there'd a whole lot of energy consumed in the production and shipping of the candles as well.

Still, a candlelit dinner for two is much more romantic than one with a bare light bulb stuck in the middle of the table.

Answer 4

lots of peopel seem to know that incandesanct light bulbs are poor converters of electricity into light. Fewer seem to realise that a candle flame is even worse. How much worse, Im not sure, but it is worse. Not so sure about your electricity grid loosing 2/3rds of the energy along the way, I'd say your supplier needs to invest in better infrastructure. A 30% loss in the grid is considered high.

But, then if we are considering total energy I guess we have to consider where the electricity co mes from, ie how it is generated. If its hydro, then thats pretty efficient say 80+% of potential energy in comes out as electricity. So the humble light bulb is overall not doing to badly. And nil green house gasses. If the power station is coal or gas or oil fired then at very best its around 50% of energy in as electricity out with lots of green house gases. Not so good for the light bulb.

Ok what about candles, if made from petroleum derived parrafin wax, then, manufacture uses a bit of energy and produces green house gases, and burning them definitely does. Not real good. But if you use nice smelly tallow candles made from rendered animal fat, well thats a renewable resource, no carbon emmissions when you burn them. Ruminants are however renouned for their explusion of methane gas into the atmosphere, and methane is 50 times ad much of a green house gas as CO2. So maybe thats not so clever afterall.  Besides it would be an interesting calculation to work out just how many animals need to be slaughtered each day to produce the tallow to replace all the incandecent light bulbs currently in use. I suspect one h**l of a big blood bath.

Anotherunwanted side effect, will be the number of house fires due to unattended candles. I live in a town with frequent black outs, and candle started fires have killed so many children in house fires it just isn't funny.

Try using 50 candles in your house in mid summer and see if you might not prefer a single 60W light bulb.

Direct comparisons of one technology over another are not always simple, as you have to compare all the factors and and keep some kind of equivelence, in this case the light output.

By the way ooil lamps are about just the same efficiency as candles as they rely on the same type of flame, similar temperature, similar fuel.(flames glow because of unburnt carbon from the fuel in the flame). A mantle pressure lamp is more efficient, using a hotter cleaner burning flame  (all the fuel is completely combusted) And the heat is converted to light by the incandecent mantle. A lot brighter than a candle and a lot more efficient.

Answer 5

I would guess yes.  A filament bulb loses most of its energy as heat, only about 10% is light energy.  And the transmission of electricty to your home is only about 20/30% efficient.

Answer 6

looking at power in vs power or work out (in this case light), the light bulb is on the order of 30 times more efficient than the candle.  That is why we use electric lights...as a side note, the 5,000 or more year old oil lamp is much more efficient than the candle.