Euro Condom

[musht]

12v 50w halogens are next on the hit list!

 

So it would appear , but possibly due to incredibly poor information:

 

http://www.energyrating.gov.au/library/pub...h-lamps2001.pdf quote from 11.5

 

"Tungsten halogen lamps have marginally higher efficacy than standard incandescent lamps. Low

voltage tungsten halogen system losses can be very high due to the use of transformers. Losses in

typical transformers are often greater than 20%."

 

Someone is getting their numbers from 2 dice in a cup.

 

Information of this execrable quality from a public body is really shocking but demonstrates the quality of info getting fed to an untechnical public from untechnical policy makers.

[david.elsbury]

I wonder if, when they refer to a "typical transformer" they are referring to a wirewound ("conventional") style or to a more modern, electronic style. I thought that most electronic transformers were pretty good for efficency?

[musht]

Most electronic lighting transformers, really a form of switch mode power supply, will get 90% + efficiency, lot of LED drivers don`t hit this level of efficency, conventional wound transformers still don`t dump 20% as heat, never noticed a 200VA trafo running with 40W+ of heat to lose....

 

A concurrent post has been automatically merged from this point on.

 

The power factor is of very limited relevance, the fuel cost of producing electricity is based on KW not on KVA.

The price paid by the consumer is also based on KW and not on KVA.

 

Exactly consumers in dom3stic property will pay on kWh because their meters largely ignore power factor, virtually any larger consumer will have metering that will be affected by power factor , hence use of Power Factor Correction on almost anything fluoro/discharge made for commercial use.

 

Power factor getting dragged out also means larger losses in transformers in the disrtibution network, lets be honest power factor is of major relevance to the distribution network.

[David A]

A transformer can be 0% efficient if it is plugged in with no load but fully loaded will be 95% efficient.So any value between 0 and 95 can be "proven".

Switched mode supplies are a potentially serious problem because billions of them will produce harmonic pollution on the grid.

[Don Allen]

From an Australian govenrment energyrating website Halogen Lighting Transformers MEPS

"Losses occurring whilst the transformers are at full load represent the majority of losses. For the most popular 50-60VA transformer size, these losses vary between 3W and 16W per transformer. Electronic units of this size generally have losses of around 4W, whilst a typical magnetic transformer has losses of around 14W."

 

They did put some proper research into this one.

[Tomo]

The power factor is of very limited relevance, the fuel cost of producing electricity is based on KW not on KVA.

A poor power factor increases the losses in the national grid and is therefore to be avoided.

Please stop contradicting yourself in the same post.

 

Energy wasted in the transmission system must be generated.

[adam2]

The power factor is of very limited relevance, the fuel cost of producing electricity is based on KW not on KVA.

A poor power factor increases the losses in the national grid and is therefore to be avoided.

Please stop contradicting yourself in the same post.

 

Energy wasted in the transmission system must be generated.

 

I can not agree that my remarks above are contradictory.

 

Poor power factor increases the losses in the national grid, and such losses must be generated.

However the losses are quite small, and not of great concern in practice except for very large loads.

 

If a consumer uses 100KW at unity power factor, then about 110KW must be generated, due to transmission losses.

If a consumer uses 100KW at a poor power factor, then the losses in transmision increase by around 30%, from 10KW to about 13KW, therefore on acount of the poor power factor, the power generated has been increased from 110 KW to 113KW.

 

On small supplies no extra charge is made for poor power factor, the effect on the national grid being so small as to make the slightly more complex meter not worthwhile.

 

On larger supplies the power factor is measured, and a penalty imposed if it is low.

The power factor charge will be a relativly small part of the bill, which will consist mainly of the charge for KWH consumed.

 

The use of 100KW of incandescent lamps will require the generation of 110KW as noted above.

 

If instead, one uses 25KW of CFLs to achieve the same light, then the transmision losses will be not 10% but 13% due to the poor power factor. The losses will be about 3.25KW, requireing that 28.25KW be generated.

 

Therefore although the losses in transmision have been increased from 10% to 13%, the KW lost has actually decreased from 10 to 3.25KW, to produce the same amount of light.

 

Finaly I would point out that utilities give out free or subsidised CFLs to the elderly, would they do this if use of such lamps had a significant adverse effect on the network?