As previously noted on discussions about energy efficiency, up until now there hasn’t been a drop-in efficient replacement for low-voltage halogen downlights. There is now.
The new light emitting diode downlight plugs straight into the same fittings as existing halogens. It will last virtually forever. It puts out almost the same amount of light. And it uses 90% less power. The only catch is the cost – they don’t really make financial sense right now. If you borrowed money on your home loan to buy one, the interest bill would be enough to run a conventional halogen three hours a day. But that will almost certainly change over time.
And the best part about it is that it doesn’t require any behavioural changes, unlike the bloody Carbon Cops on the ABC. Does anybody seriously think that “watching television together instead of in separate rooms” or “driving less” is going to last more than a couple of months?
Nope, but I think the show was worthwhile for raising awareness. I learned a few things like the cover you can put behind halogens (in the ceiling) that prevents heat escaping and allows you to insulate around the halogen fitting.
I’m very skeptical of the claims in that ad Robert. Do you actually have one of these lights? LED efficiency is usually no better than halogen.
Note that there are compact fluorescent replacements for GU-10 (240V) halogen downlights — Bunnings has the Megaman brand for c. $20 each. These are 11W and provide similar light to a 50W halogen. These are also available in 7W and 9W — the are not dimmable. Note that 240V downlights have the advantage that no energy is lost in transformers.
I’m progressively replacing my halogens with compact flourescents, as the bulbs go. I would also like to find some way of reducing the flow of air through the socket — I suspect I lose quite a bit of heat that way.
Dimmable?
Sorry, on taking a gander at your link, they are dimmable.
Tom – LEDs are WAY more efficient. No contest.
Also, if you do replace your halogens you could get up in the cieling and plug up all the gaps no worries – they’re only required for the airflow required to cool the halogens. CF or LED won’t heat up anyway.
*ahem*, ceiling.
Ah, but will they be stark hospital flouro-like, or nice soft pretty light? Until they find a way to make eco friendly bulbs aesthetically pleasing I can’t see many people making the switch.
It says the colour is warm white so it should look pretty reasonable.
The heat sink on it looks pretty big so I wouldn’t be too confident that it doesn’t need airflow.
Jed, the 11W compact fluoros are very close in brightness to a 50W halogen, and they have exactly the same fitting as a GU-10 halogen, so fitting one is no more difficult than replacing a burnt out halogen. They are longer than the equivalent halogen, which I suppose could be a problem in some applications, but is fine for ceiling fitted downlights. They are available as ‘warm white’ or ‘cool white’.
FDB, there are some white LEDs which are more efficient than halogens, and plenty which are not. It is very common for people to take a LED light with a narrow beam, measure a spot in the middle and pronounce it as producing as many lumens as a 60 degree halogen. There is a lot of misleading advertising in this area. It’s true that white LED efficiency is increasing.
Be careful to check what transformer you have if replacing 12 volt halogens with LED. I believe they can’t run off the electronic (nowadays most common) transformers as they have a minimum wattage to be drawn which an LED will not fill.
Both the 12 volt LED and GU-10 240 volt CFL use nominal power, but neither will provide light as bright as halogen… yet. They both look bright at the light source, but the light can’t ‘travel’ as far as halogen. Half a metre from either of these lamps and the brightness has reduced significantly.
Having said that, the technology is advancing and improving quite quickly. Both are available in various colour temperatures. So you can have your stark white (7 eleven) look, or the warm (we all look prettier) colour.
Best advice… No matter what type of lamp you use, downlights are an inefficient way to provide general light
And the best part about it is that it doesn’t require any behavioural changes
I can see your point, but the thing is that we’ve all made behavioural changes into our current problematic state – which is a problem for us as individuals, in terms of health as much as anything else – and so it’s not completely ridiculous to think that we need to make behavioural changes to help get out of the state the world’s in – though I realise that structural/economic changes have more consequence. Still, it’s just television and mildly entertaining (though I thought Eco-House Challenge on SBS was more serious in its approach.)
Suz: I suppose my objection to that kind of thing is that solutions that require continuous human conscientiousness to not do things that provide short-term rewards have a track record of not working very well.
Consider the track record of dieting and abstinence-only sex education, for instance.
Halogen lights should be banned as per incandescent. They consume nearly as much energy, have very inefficient light distribution, create hot loss as you cannot insulate close to them, and are a major fire risk in the roof space.
A classic case of a trend that is in fact bad on all counts.
Plug in diode or compact fluoro replacements are definately the way to go.
It is getting close to a time when the wiring of houses can be rethought. Lighting can all be done on low voltage and switching can be performed with a can bus type system as is used in cars for central locking. Net gain: less copper, lower power consumption, increased functionallity, lower impact from power outages (lighting can be maintained by batteries), and solar power generation compatibility. Coupled with some of the very interesting research under way on cordless power transmission the near future is looking very exciting indeed.
The prophets of energy doom are destined to be a disappointed bunch of people judging by the immense explosion of technological activity triggered by a desire to change.
http://www.ccc.govt.nz/environment/
This is the environment page from my favourite city. The Mayor tells me that it is packed with initiatives. I have only started to look at it but the variety of information available talks about peoples commitment to improve the way we do things.
carbonsink .. do you have a link/info about these halogen covers mentioned in Carbon Cops?
carbonsink .. no worries .. found something:
http://www.lightingpro.com.au/catalog/product_info.php?cPath=26_37&products_id=186&gclid=COiFnfrl1Y0CFSjKhgodDCLGag
Aidan, or here — cheaper if you don’t want the transformer isolator.
The best way to work out what the light will look like is the colour temperature rating (in Kelvin).
2700K gives a pleasant warm light similar to an incandescent. 3000K gives a slightly cooler light, but still within the range of acceptability. 4000K is getting too blue, but I’ve still seen 4000K lamps described as “warm white”.
I’m a bit suspicious of the Galaxy LED lamp because the product info doesn’t provide the colour temperature. I suspect the light will be too cold.
I replaced all my halogen downlights with the GU10 Megaman lamps around 12 months ago. The lighting is easily as good as halogen. The 9W version gives the best quality light at 2700K; the 11 watt version has 3000K (I have those in my kitchen). Both types provide equivalent light to a 50W halogen.
* Low voltage requires much more copper (thicker wires) than AC as the amps are much higher.
* Switches need to be much more heavy duty to handle increased arcing from high amps.
* Low voltage does not equate to low power consumption – it is only the wattage of the light source that matters
* Power losses for DC transmission are much higher than for AC over distance – which is why all transmission lines are very high voltage AC.
End result: it is much cheaper to wire all lights for 240V and use efficient 240V lighting with an inverter (if you have batteries) than to wire DC and use DC lighting (or appliances)
Peterc,
Good points, however, mostly wrong in this case.
* the oportunity comes about through the low power requirement of LED lights. The power would be 24 volt ac supplied from a loop line that did not connect directly to switches.
* the switching is all solid state (no contacts), controlled from a switchboard mounted PLC (of which there are many on the market).
End result: less wire, lower voltages giving greater safety, better functionality, good home security features. Requires a dc to ac converter for battery connection.
Did anyone else see this guy on the New Inventors a few weeks back?
And have any idea of what he’s done or how he did it?
Solid State Lighting
Video Here(ep 23)
m
BilB,
I agree with your comments re diode lighting (which is very low wattage).
My previous post relates to halogen low voltage – which in any case use a step down transformer to convert AC to DC.
But, if you are putting in additional & separate loop line wiring (not sure what that is) for a diode-based lighting system this would be additional cost for the wire and the install, which would not be trivial.
Michael D: Smells funny to me. If he doesn’t get a patent, every other factory on the Pearl River Delta will start churning out royalty-free copies as soon as they go on the market. Which leads me to wonder if there’s some other reason why they haven’t applied for patents…
Furthermore, if you read the New Inventors forum, it seems like a number of posters there are very skeptical.
Peterc,
I was expanding on Roberts thread. There is no reason for all domestic lighting to not be LED based. The energy efficient fluros may have missed their day. There are LED alternatives for most lighting situations turning almost by the day. It is a positive step forward. The light properties are a problem but maybe that can be aided with flourescent filters or something.
The Keith Higgins innovation. This guy claims to have developed an improvement to the way that the leds are manufactured which leads to more efficient LED performance. If it comes down to improved materials or bonding methods then this may be very difficult for the average techno chop shop to analyze and copy.
The problem with fluoros (including compact fluoros) and white LEDs is that the light is highly “banded” ie there are pronounced spectral lines in the spectrum mix a problem not so pronounced with incandescent and sunlight.
We did not evolve to be comfortable with sharp spectral lines and it is a little deceitful to rate fluoros in terms of their colour temperature because this “temperature” refers to the quality of light produced by a tungsten filament( ie incandescent) at the specified temperature.
Michael D,
I have just designed the switched mode power supply in my head for the Blue Mountains guy and his white LEDs.I used a flyback choke and an appropiate FET .It produces very little heat because the FET switching times are very small and consequently the efficiency is very high. It uses the current drawn by the LED to control the switched mark space rather than using the usual voltage control which would be used for say, a halogen.
The new white LEDs are about the same luminous efficiency as the standard 32 Watt flouro say 60 lumens/Watt.
They cost a motza but last 100,000 hours plus. The intrinsic cost is trivial Expect large cost reductions in the years to come. Already you can buy plug in replacements for the standard flouro. The market is office buildins where the replacement firms will supply the fittings and lamps for zero in return for the replacement contract. In effect the new lamps will last the life of the building and entirely avoid replacement , recycling and disposal costs.. That is why they cost so much.Capish? The cost reductions will not come until the office replacement market is saturated
You can buy off the shelf chips that are specifically designed for LED driving, they are switch-mode current controlled sources and do a very good job. I have been using these for years.
Petrc; er power loss in DC transmission is less than at AC, hence the use of DC transmission when they need to maximise efficiency. When compared with single phase AC your losses with DC come down by a factor of 1/1.4 – (.707) very roughly, there is a square law in there some-where. Can’t remember the exact relationship but it is significant. AC is only better because it is easier to transform the voltage up for long distances and bring it down again where you need it.
Danny le roux,
Can you design a switch mode power supply, 16 volts 30 amps, that can reliably and contiuously regulate power into a short circuit?
If you are switching rectified 240 AC you need more than just a chip but also some sort of inductor and a few other bits.
BilB,
13.8 V switched mode large current power supplies are common things used by CB freaks.The supplies usually protect themselves quite well for short circuits because the output energy is stored in the “secondary” of a “transformer” which is really an inductor.Immediately after a short the next “primary” switched pulse has a noticeable change in its di/dt which can activate a protection mechanism.The data for the chips which drive the power switching device usually boast that control is done on a cycle by cycle basis.
If I were to make your supply I would modify an old tower computer supply and use a TDA4605 ( $5) as the FET driver and rewind the transformer for 16V instead of 5V. If you Google the plain old TDA4605 and look at the pdf data sheet you can see that it specifies elaborate current protection.
The Siemens pdf even gives a complete circuit diagram.
16v is an unusual voltage and I am wondering what you would use it for.
Thanks for that Danny. I have a product that cleans tig weld discolouration by passing current through an electrolyte. The applicator is a conductive material with about 1 ohm of resistance so the power supply (a transformer with a .1 ohm resistor in series) is driving into a short circuit effectively and continuously. The product was intended to be an electronic one but the electronics guy failed to come up with a reliable circuit. 16 volts is what works best.