Led Candle
Are candles more energy efficient than LED bulbs of the same luminosity?
How many watts/lumen are used by each to produce the same luminosity.
Depends how you define efficiency and where you make the cut. A small candle (‘Teelicht’ in German, the kind you put under a pot of tea to keep it warm) provides around 35W of heat. Assuming (!) that this is comparable to the light output of roughly a 0.1 W LED, the candle would use 350 times more energy than the LED.
The problem is: how much energy was used to make the candle, and how much energy was used to create the electricity that powers your LED?
Let’s spin this: assume that the production of the candle didn’t use any energy (worst case for the assumption that the LED is better than the candle). Further assume that the thermal efficiency of the power station is 30% (might be better, might be worse), the efficiency of electricity transport to your house is at 90% and the efficiency of the LED power supply is at 70%. Then you’ll get 0.3 x 0.9 x 0.7 = 0.189 or just short of 19% efficiency from the burning of gas/coal at the power station to the input of the LED. In turn, that means that in order to power the LED with 0.1 W, you’ll have to burn a bit over 0.5 W worth of coal/gas at the power station – still much less than the 35 W from the candle.
You may notice that I didn’t put in the efficiency of the LED. As long as we say that a LED that is powered with 0.1 W is as bright as the candle, that value is irrelevant. However, you might find that different LEDs at 0.1 W shine with a different brightness. But even if you use a 1 W or 2 W LED (and a current 2 W LED is _very_ bright compared to a candle), that still would see the LED better off.
ThinkGeek LED Candle
|
|
Candlelight Vigil LED Hand Held Candlestick – Set of 2 Hand-held LED candlesticks for candlelight vigil, set of 2. For Church activities, weddings, floral arrangements and more. The LED flame tip flickers like a real candle. 700 Hour Run Time 2 x AA (sold seperate) 6 3/8 Tall x .75 In. Dia. Amber Flickering Flame… |
|
|
Earthmate EP05129 5-Watt Dimmable Candle 2700K Bulb, 6 Pack $80.00 … |
|
|
Wilton Flameless Votives $4.99 Flicker like real candles Perfect for anywhere candles are not allowed or desired Powered by replaceable batteries (CR2032-included) Avg hours of operation:24+ Votive holders measure 1 5/8″ h x 2″ diameter Light measure 1 1/4″ h x 1 3/8″ w Wilton stock #1006-7137… |
|
|
Submersible Battery LED 10 Lights~WHITE~wedding~tea Light $9.50 WHITE -Submersible Underwater Lights all with batteries included- Just twist the light it is an easy on/off switch with replaceable batteries. The battery included gives the lights 12-16 hours of operation. These are not returnable. The batteries for these are CR2032-and 2 are used in each light. The size of these lights are 1″ tall and 1 1/4″ across. These lights can be used for Parties in arrang… |
|
|
Inglow CG10286CR6 Battery-Operated 1-3/4-Inch Flameless Wax-Covered LED Votive Candle, 6-Pack, Cream $10.13 … |
|
|
MAGLITE M2A016 AA Mini Flashlight, Black $7.51 … |
|
|
CR2032 Lithium Battery, Package of 5 (5 Packs 25 Batteries) $0.45 5 packs of 5 CR2031 batteries… |
|
|
GE 48402 60-Watt Candelabra Light Bulb, Blunt Tip, 2-Pack $5.49 GE Crystal Clear bulbs add a decorative touch and warm glow. These bulbs provide maximum glitter in crystal and shiny metal fixtures. Use GE Crystal Clear bulbs in any fixture where the bulb is visible…. |
|
|
GE 75368 Energy Smart 13-Watt Spiral Compact Fluorescent Bulb, Candelabra Base, 2-Pack $11.50 GE, FLE13HT2/2CANDP, 2 Pack, 13W, Mini Twist Compact Fluorescent Bulb, Electronic Ballast, Equivalent To 60W Incandescent, 2700 Kelvin Temperature, 80 Cri, 8,000 Hours Rated Life, 850 Lumens, Candelabra Based, Energy Star Compliant, Carded…. |
|
|
Mastech Digital Illuminance/Light Meter LX1330B , 0 – 200,000 Lux Luxmeter $79.95 The LX1330B can measure from 0 up to 200,000 lux, you can switch the units between lux and footcandle by simply pressing a button. It’s powered by a 9V battery, which last for 200 hours or even longer. Other nice features include data hold, auto zero and more. Features: High Accuracy and rapid response Auto Zeroing Over-range indication Unit and Sign display for easy reading Data Hold L… |