I have +/- 50 10w halogen lights running on transformers at 12v. I want to switch these to LEDs.

Some quotes are coming in with keeping the 12v transformers and getting 12v LEDs and some are on removing the transformers and installing 240v LEDs.

Mains is 240v here. I also plan to possibly go off the grid with solar electricity in future.

Which is better from an energy efficiency perspective? Other things I should consider?

  • Turns out 220/240v is not allowed on G4 connectors in South Africa. So will go 12v. Most of my lights are G4.
    – Louis
    Jan 25 '16 at 9:15

There are multiple ways of looking at this, high quality 12V LEDs are hard to find and can be quite expensive... however some people are very satisfied with the 12V LEDs that are available. Transformers also waste energy but the efficiency can vary greatly. As long as you are on the grid, I would use higher voltage LEDs since they're cheaper and you'll use less energy. But if you do go off grid, you can run the 12V right off your batteries. This can be a nice advantage, especially if you use a 12V battery bank; however, most quality off grid systems use 48V as a first preference or 24V as a second choice, so you would most likely need a DC to DC converter (or power supply) in order to run 12V anyways.

I guess that is really is a matter of preference but I would go for the simplicity of easier to find, high quality, higher voltage LEDs, with no transformers wasting your energy unless it is important to be able to use it straight off a battery

Thanks, Maxfield Solar


I would stay with 12V if possible.

Because LEDs draw very little current, a minimum load requirement may be a factor if there are any electronic parts such as a dimmer or a transformer.

For general residential lighting 12V would be the best choice. Running at higher voltages for incandescent, halogens and especially for LEDs is unnecessary and probably does more harm than good. Compare it to using a sledge hammer for hanging a picture.

  • I don't understand your answer. I have to use a transformer to get from 240v to 12v. If I use 12v I would need a transformer which adds to the power consumption right? Also my mains is 240v. So that would be what I have by default.
    – Louis
    Sep 23 '15 at 13:07
  • 1
    Maybe. If the current transformer is magnetic it should work regardless of a minimum load requirement. But if using a electronic/digital dimmer it may not support the minimum load, but simple to fix with a mechanical/magnetic dimmer type.
    – Kris
    Sep 23 '15 at 13:11
  • With LEDs the minimum load is often more crucial than the maximum. But good to know both.
    – Kris
    Sep 23 '15 at 13:13
  • You can also leave one halogen to ensure minimum load, if needed
    – Dan
    Sep 25 '15 at 18:50

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