• Jan 20th 2011 at 7:01PM
  • 10



The average electric vehicle's battery pack has the energy equivalent of only 1-2 gallons of gas. If you had that much in your IC vehicle, you'd be looking for a gas station right about now. However, since electric motors are much more efficient than internal combustion engines, a decent range can still be obtained from these battery packs. One downside to going farther on less energy is that accessories such as lighting are about 10 times more detrimental to your range than they would be on a gasoline vehicle.

Jonathan Dunlap, the automotive lighting engineer and product marketing manager with OSRAM SYLVANIA, says that LED (light emitting diode) lighting can have a significant impact on an electric vehicle's range. Over only that last 2-3 years, the efficiency of LEDs has increased to the point where LEDs use less than 25% the energy of halogen bulbs (and this will only get better in the coming years). So, how much extra range can an EV get by using today's LED headlights? According to Dunlap:

An efficient LED headlamp system can extend vehicle range by nearly six miles (9.5 km). Even with conventional vehicles, a 28 watt LED system emits only 196 grams of carbon dioxide per 100 kilometers compared to 768 grams of carbon dioxide per 100 kilometers from conventional 110 watt H7 halogen bulbs.
LEDs have additional benefits such as extremely long life (50,000 hours is not uncommon) and vibration tolerance, meaning they can last the life of the car. The main hurdle at this point is getting upfront costs down.

[Source: OSRAM]


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  • 10 Comments
      • 8 Months Ago
      With LEDs light pattern is easier to control and head lamps may be designed more freely.
      BipDBo
      • 8 Months Ago
      LEDs also dramatically reduce building lighting, and in cases of large fixtures such as outdoor site lighting, they actually pay themselves off in around 3-4 years as compared to HID. This is fairly new in the market and the building energy codes need to catch up.
      • 8 Months Ago
      No duh.
      I have a magicshine 900 and it produces more power *and spread* than a standard car headlight on 'high' with a meager 13w.

      Every car should have this kind of lighting. Alternators can be downsized and engine drag can be reduced on ICE cars, increasing their efficiency, with such lighting.
        • 8 Months Ago
        Why would you think i'd vote you down for that? I am surprised that it uses half the power.. that's way cool. Oh well, the Magicshine ain't bad, not for the price. I think it could even be used in cars.. :p
        • 8 Months Ago
        and the Seoul P7 diode used in that is only about half as efficient as Cree's XM-L.
        remember to vote me down as usual
      • 8 Months Ago
      Umm, does Osram have an LED headlight to sell?

      Let's do the math:

      A typical Halogen headlight bulb is 55W. OSRAM says above that the LED system is 28W. So LED will save 82W for the pair.

      An EV uses about 300Wh/mile in real world highway driving. Therefore, you'd have to be driving for 3.6 hours to save 1 mile's worth of energy with the LEDs over the halogens. Thus, to save 6 miles' worth of energy you'd have to drive for 22 hours between charges. Not even a Tesla can do that (by a long shot).

      The case is even more extreme with Xenon HIDs. They are typically 35W per bulb or a saving of 42W for the pair between that and LED. So now you'd have to drive for over 7 hours to save 1 mile of energy or 43 hours for the claimed 6 miles' saving.

      I allow for a mile hit on range when driving the Tesla at night. That's being generous.
      • 8 Months Ago
      They are already in the Leaf which should help to drive costs down.
      • 8 Months Ago
      And this is a supposed revelation?
      LEDs take less enrgy than incandecents - brilliant!
      LOL
      Plus my math 28 watts vs. 110 watts is a smidge more than 25% (not less as stated in the article)
      WOT
      • 8 Months Ago
      This is utter nonsense unless one changes miles to feet or assumes the headlights being traded for LED lights are can burn trees from 1000 yards. A very efficient EV driving at 55 and burning 10,000 watts is not going to save miles in range from even a 200 watt savings.

      At 1/4 power on a LEAF the consumption is 20 kw please explain how someone figured saving a couple hundred watts is going to add miles. Switching to LEDs may save a few feet in range not miles.
        • 8 Months Ago
        yeah I agree the 10km extension seems a tad extreme. LED is definitely the way and the latest Cree XM-L series at 160lm/watt is outstanding for cars. but for a 100watt saving to become 10km driving you have to be on the road about 15hours on a single charge with the lights on and that only happens with a tesla in the worst gridlock ever.

        the coolest thing about good LED lights is that it's such an elegant solution with almost no thermal concerns and you can leave the lights on if you're camping or some such and not worry about it draining the batteries because you can run them for days and the drain wont even be noticable. A tesla roadster could have its lights on for over 200 days straight on a single charge.
        compared to incandescents it's like they don't even use power
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