Can any electricians out there explain to me if low voltage spotlights are easier on electricity than 230V ones? If Power=Voltage X Current then a low voltage light uses more current, so why not more units of electricity?
A 25watt low (12v) voltage light costs as much to run as a 25 watt 215volt bulb.
25 watts for 40 hours is 1 Kilowatt/hour, whichever way you look at it.
However, there are resistance/heat losses, due to the transformer that brings it down to 12v, so low voltage is probably fractionally more, as it's system has used energy in giving you the 12v.
I've just been shopping for downlighters today, and 2 shops assured me that low voltage spots use a fraction of the electricity compared to 230V versions, whilst still giving the same light. I tried to get them to explain the difference, which they couldn't, but they argued that this was the simple reason for low voltage being so popular, that everyone knew this! I'm more confused than ever.
A transformer that changes 230 Volt in to 12 volt or 24 volt needs energy.This energy you can't use for illumination,its gone for ever,even if the lights are switched off the transformer might still be running.
It might sound heretic but:Nothing comes from nothing.
A job-here the transforming-costs energy.
I have a kitchen extractor fan which contains two low
voltage lights , each eating up 20 watts.I used my energy monitor to measure the energy usage:60 watts!
I took out one light :still consuming 40 watts.I took out the other light:still 20 watts consumption!Only when I pulled the plug the monitor showed zero usage.So a third of the el.energy was used by the transformer.Keep in mind:The more watts the transformer delivers (in my case it where 40 watts for the both lights)the more energy it will consume.
You can buy an energy monitor in LIDL (as well as an illuminated extractor fan) very cheap.That lead me to the conclusion that there is only one way to lower the energy use of the extractor fan:to build in a switch.So when I need no light I have to switch off the transformer which will automatically switch off the light as well.
If you decide to buy your lamps than go to a different shop,obviously the staff in the shop you mentioned is not well educated and not trained at all.
PS.Did you know that many dimmers use energy even when the lights are not on?!Invest € 7 and measure it your self.
Heres one, When you leave your mobile phone charge plugged in all the time, even if you are not charging your phone as i recall it uses a tiny bit of electricity. Now if you add up the amount of chargers left plugged in right accross the country, and not just ones for mobile phones all lying there plugged in using a tiny bit of power. Ask yourself how much energy are they using in total.
Its energy awareness week next week. I hope they really promote this kind of simple knowledge
also, on the topic of energy awareness, all the electrical appliances left on standby are constantly using electricity. It may not be much but add up several tvs, stereos etc over a year and it makes a difference. Switch the tv off at the switch at night and when you go out and you will save on the ESB bill.