Energy saving or not?

[Jonjel]

I am confused about the energy saving which is alleged there will be by us all converting to energy saving bulbs, by law.

Agreed an 11 watt energy saving bulb will consume less than a 60 watt incandescent lamp. However what does not seem to be in the equation is the additional cost of manufacture of the energy saver, nor the disposal cost of that bulb, though I imagine that 99% when expired will go in the bin with the household rubbish.

What is also not in the equation is the heat output from an incandescent bulb. If you have say 3 on in your home that is 180 watts you don’t need in heating bills.

I am also puzzled by the increasing popularity of small down-lights, which are still legal to buy. These run at about 50 watts and I know of a couple of houses where they seem to have at least 300 watts of lighting on in the kitchen. I am fitting some in my new kitchen and at considerable expense opting for energy saving bulbs, not to save the planet, but to save my wallet!

So, has anyone done the real calculations on this?

[eamonnshute]

I estimate that 10% of my domestic fuel bill is for lighting, and I use incandescent lights. As you say, the surplus energy helps to heat the house. The only time that this extra heat is wasted is in summer, but then it is light till late so I don't have the lights on much anyway.

Although I haven't gone into detailed calculations, energy saving bulbs would not save much money, and they have the disadvantage of being slow to come to full power, and they contain mercury. Unfortunately we will soon have no choice. The EU is guilty of fiddling while Rome burns.

[Jonjel]

I have fitted energy savers in the lamps and lights that remain on most of the day. Some are left on 24/7. Rural area and total black on some winters nights so I like to have a glimmer from downstairs so I can get up for a pee without braining myself on a bookshelf - or worse still walk straight into the edge of a partly open door!

[speakertoanimals]

I find the wasted energy heats the house, hence no saving line to be rather suspicious!

The point of a lightbulb is to provide light, NOT heat, hence surely the most efficient and sane way to design a bulb is to find a bulb that most efficiently converts electrical power to light.

If we are trying to say old fashioned bulbs are useful because they provide heat as well, what about the fac t that they aren't placed where any sane person would place a heater in the first place!


Then we have lifetime issues, and manufacturing costs. If I have a bulb that converts electrical power more efficiently to light, lasts longer, even if it may cost more to manufacture, then that could be a plus over the lifetime of the bulb. Plus if they can be recycled as well..................

I know that some people don't like the spectrum of light provided, but I'm sure that those who changed from gas mantles to electric said the same..........................

[Jonjel]

STA.

Don't misunderstand me. I use a lot of energy savers, virtually the whole house. That is not in an attempt to reduce the hole in the ozone layer but to save the hole in my wallet. I am even silly enough to write the date I fitted the bulb on the base with a felt tip - so I can see if they really do last 10,000 hours! I do know that over time the light output lessens, and that is not just a build up of dust.

I was simply questioning the actual saving of power when you take into account the power used in production, and the materials.

And the overwhelming majority of these bulbs are made in the far east, so are we simply 'exporting' pollution.

[jean]

When I was a child in the 1950s, we had at home a very old but still-functioning light bulb. The filament was very long, and the glass surrounding it had a small nipple at the end so I assume the air had been extracted.

It seemed a bit suspicious that it could have lasted for so long when the modern bulbs had such a short life - and of course the new low-energy bulbs are recommended to us also on the grounds of their 'long life'.

Mind you, we only had the one, so maybe it was an aberration.

Does anyone know what I'm talking about?

[Jonjel]

Yes I do Jean.

In 'olden times' the bulb would have been made and then evacuated via a small stem at the top which was then 'necked off' with a flame. These days it is made as a complete bulb and necked off at the connector end. Much faster and more efficient production.

It is a common misconception that bulbs are under complete vacuum (which can never be achieved). They are evacuated then partially back filled with an inert gas such as argon or nitrogen. Other gasses such as xenon are used in some bulbs .

[jean]

Thanks.

But can you say why ours lasted for so long compared with modern ones?

[Jonjel]

And I am an idiot. I meant to say Xenon!

The only reason I can think of Jean is an element of luck. Maybe the glass was a little thicker and less permeable, maybe the filament was different, maybe the mix of gas in the bulb was reducing and not oxidising. I would not worry about it, just enjoy it and if it fails stick it on a shelf as an ornament!

(We used to carefully break the glass off 110v 60w bulbs and use the filaments as a resistance gauge! A lot cheaper than the commercial alternative)

[helen]

Here's a link to lightbulb manufacture www.youtube.com/watch?v=BylLOWRojyY from the Discovery Channel. How much energy is used to make lightbulbs. The little flourescent bulbs we are encouraged to use these days, they seem far more complicated to produce and they contain mercury. So they cost a tenth of the price of an incandescent bulb to run but how much more to manufacture, are they cheaper to manufacture? They don't seem to last much longer than the old bulbs in my house. I don't have a problem with the quality of light, I used to live in a house on Dartmoor with borax gas mantles and propane! It's all very well saving money on our electricity bills but I fear a false economy being invested in here. Anyone else have a comment?

[helen]

I remember an episode of Steptoe and Son where Harold and Albert were trying to warm themselves from a 60 watt lightbulb. It didn't work! I reckon that the contribution to the warming of my house from lightbulbs is about the equivalent to the presence of me, dog, cat and my kids and friends when they're here; they don't do light though!

[Jonjel]

I made darkroom developing bath heaters when I was 'into' photography by using small incandescent bulbs inside biscuit tins. It worked rather well.

Ah, the joys of my first caravan with gas lamps. A warm spot, and light as a by-product if you were lucky. And the care of wrapping the mantles up in toilet paper before each journey, only to find them in bits on arrival and replacing them with new...

[helen]

I have a 'slow cooker' which is in the process of converting some lamb shanks and various vegitables into something gorgeous. It's powered by a lightbulb!. When I was a child my mum had a bed heater which was pink iron can containing a light bulb so I have to admit there some heat there.
I loved the gas lights in our wooden house but we let it to two students from my father in law's school whilst we we were on holiday and they burned it down, they were Portugese and didn't do propane, they were candle boys.

It was Swann who invented the lightbulb not that genius but mischievious charlaton Eddison! en.wikipedia.org/wiki/Joseph_Swan

[speakertoanimals]

SLow cookers aside, the point is that an actual heater uses kilowatts, an old-fashioned incandescent 100 watts or less. Power is power, and the ony way you can get that hot with that little power is by confining it all inside a biscuit tin..................

[helen]

Light Emitting Diodes is the way forward for illumination now. I've seen them on buses and trains and traffic lights. No heat though, where did this idea that light bulbs could heat our homes come from? It's ludicrous bar my mums bed heater and my slow cooker! Heat balls.....I should say so! I like light bulbs though, maybe it's my age.