[mythtv-users] [Slightly OT] solar power for all our gadgets

[Simon Hobson]

raphy wrote:

>  > That's the crux of it. If the heating is electric then there is ZERO
>>  difference in efficiency - both the electric heating and light bulb are 100%
>>  efficient at turning incoming electricity into heat. For other forms of
>>  heating there will be some saving - but I don't know what it will be other
>>  than "nothing like 80%".
>>
>
>This is utterly wrong. I don't need to mention anything more than the
>fact that your electric heater doesn't emit nearly as much or even the
>same wavelengths of visible light that your light bulb does to debunk
>that one.

Thank you for proving the point ! Lets not allow facts to get in the 
way of prejudice.

So, I'm sat at home, and I've just pulled the curtains closed (which 
I have actually, it's going dark). Say I have a light bulb consuming 
100W of electricity - and directly emitting 90W of heat. It's 
therefore also emitting 10W as visible light.

Without ignoring the laws of physics, and in particular the law of 
conservation of energy, could you please explain where that 10W goes 
to if it doesn't heat up the room ?



OK I'll admit that after the nice warm day we've had here, the 
heating isn't on. But it will be by the morning - a cold night is 
forecast. I did say things are actually quite complicated.

PS - I don't actually have a 100W bulb, the lights in this room (like 
the majority in the house) are CFL.


The other issue people casually forget, is that CFLs really are not a 
direct replacement for incandescent bulbs in many situations. They 
are really slow to start, and then need to warm up before they give a 
usable amount of light - though that varies with make. Sometimes I 
can walk into a room, do whatever it was I needed the light for, and 
leave - before the CFL lights have got around to doing something 
useful.

And I'd like to see you fit a CFL in an Anglepoise and have it stay in place !



Johnny wrote:
>  > Don't get me wrong. What I am NOT saying is that CFLs don't save energy
>>  overall. What I AM saying is that it's not 80% (even leaving out all
>>  production and shipping costs) in a great many cases.
>>
>
>That is fair, I misinterpreted your initial statements. The 80% does
>need to be the starting point though. You start by comparing how much
>light you get vs how much electricity is used. A CFL uses 20% of the
>electricity that an incandescent uses to produce the same amount of
>light. From there you can consider the secondary effects others have
>promoted like home heating, manufacturing, shipping ,etc. When all the
>cards are on the table, as you are arguing, the overall efficiency may
>be more or less depending on a lot of factors. But the final outcome
>will be the same, CFL are better in terms of overall efficiency.
>
>Also an electric heater will be more efficient at heating your home
>than a light bulb, even if the underlying mechanism is similar, there
>are many other factors. See this from the EPA:
>http://energystar.custhelp.com/cgi-bin/energystar.cfg/php/enduser/std_adp.php?p_faqid=3868&p_created=1196785588

Hmm, reads to me like the usual sort of stuff you get from quangos* - 
yes it's technically correct but carefully written to avoid answering 
the awkward part of the question. Yes, a CFL will save more energy 
than will be used by an electric heat pump to compensate - but IME 
heat pumps are not very common (over here, YMMV). And note that at no 
point have I claimed that electric is as efficient as gas or oil in 
converting the chemical energy into heat in the house - but they are 
far from 100% themselves.


* QUANGO = Quasi Autonomous Non-Governmental Organisation.
Ie, one of those many bodies that's not part of government, but 
really it's funded by government and pushes the policies of 
government. Not sure of the status of your EnergyStar people, but we 
have several similar outfits which do fit the name.
-- 
Simon Hobson

Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
Christmas stocking fillers. Some available as e-books.