Electricity North West says plans to lower its volta ge could cut emissions by 10% and save customers £60 a year

[misterroy]

Snake oil?

[Andy Burns]

Or, per this morning's thread, bollocks.

[Harry Bloomfield, Esq.]

misterroy was thinking very hard :

For all but basic resistive equipment, such as tungsten lighting - yes.

For almost everything else, current demand will increase to compensate for a reduced voltage.

[misterroy]

Darn, missed the post this morning. thanks

[polygonum_on_google]

For tungsten lighting, in the very short term, it just might result in less electricity usage. But behaviour will compensate - turning on more lamps, using higher wattages, changing dimmer settings, etc.

I don't have figures to hand, but would be amazed if the best photons-of-visible-light-per-watt weren't achieved at the manufacturer's intended voltage, or close.

[Harry Bloomfield, Esq.]

polygonum_on_google was thinking very hard :

Tunsten is at its most efficient, watts into lumens conversion, the hotter the filament runs.

[Brian Gaff (Sofa)]

There is already a thread saying this is a load of tosh but a few messages up the list. Always read the messages before posting. ahem. Brian

[tabbypurr]

dropping 240v filament lighting to 220v makes a big drop in light output, people will thus change to higher wattages. There isn't much filament lighting left in use of course.

SMPSUs will draw more current, saving nothing.

A lot of other loads will draw a bit less but give correspondingly less output. Efficiency gains overall sound unlikely.

Some refrigeration will simply fail on 220v.

NT

[The Natural Philosopher]

Bo. That's completely wrong. Ideal filament temperatures would be well above anything that even a halogen filled bulb could tolerate.

Incandescent bulbs are a compromise between cost, efficiency and life.

[The Natural Philosopher]

In terms of visible light you want to be around the temperature of the surface of the sun. 5778K....

[harry]

Heating appliances (eg immersion heaters, ovens) will just run for longer. So, it's bollocks.

[Martin Brown]

It would extend the working life of filament bulbs somewhat.

For the kettle example given the total power used to heat the same volume of water to boiling point is virtually the same in both cases V*I*t.

Decrease V by 5% and t increases by 5%. I'd also expect proportionate resistive losses in the local distribution system to increase slightly as V is decreased and overall current drawn increases so that any gains would at best be marginal - maybe 1-2% at the sweet spot.

Thermostatic heaters will just run for a bit longer to compensate too.

Certainly not saving 10% or anything like - it is spurious greenwash.

Most domestic stuff these days is on switched mode PSU that automatically draws more current when the voltage falls.

If they were to drop the UK mains voltage to half what it is now then filament bulbs with thicker more robust filaments like in the USA are marginally less inefficient by ~20% than their UK cousins.

[Roger Hayter]

So it is more incomplete than completely wrong. It is still true that the bulbs are designed for optimal working at 240v (in the UK) but lifespan is part of the compromise as well as efficiency and colour.

[Scott]

If I decide to get my electricity from a 'full fat' supplier how will they ensure I get the correct voltage :-) I heard the electrons are DNA coded. Will this ensure the correct voltage?

[Dr S Lartius]

Tut Tut! you mean energy, not power.

[Martin Brown]

Thinner more fragile filaments are more prone to evaporative losses. The trade is higher efficacy for a shorter life (photoflood bulbs of old) or lower efficacy and a longer life.

Filament lamps designed for 110v US mains are about 20% more efficient. The thicker filament allows them to run a bit hotter without failure.

Dropping the supply voltage of filament lamps even slightly increases their working life (at the expense of light output).

[Chris Hogg]

Not DNA coded, but they are colour coded. Those electrons coming from renewable energy generators are coloured green. Modern 'green' tariff suppliers provide a special filter that sorts the green electrons from the rest, and only lets the green ones pass. It's done by measuring the vibrational frequency of the electrons - they are tuned at the generator to a frequency close to 550 THz, i.e. the green part of the visible spectrum, and then filtered at your meter. If you want to know what green electrons look like, they can often be seen in the spectacular 'aurora borealis' displays visible in northern latitudes, as the solar wind interacts with the upper atmosphere and generates green electrons.

For an extra charge, an additional filter can be provided that can block the radioactive electrons coming from nuclear power stations, should anyone want it, like Harry for example.

How else do you think they are able to ensure that they only provide green renewable energy to their customers?

:-)

[tabbypurr]

it does, but the value of the extra electricity is much greater than the cost of more bulbs. There's no real life upside.

more because kettles lose heat as they work

NT

[NY]

Just think how much energy is wasted as all the "rejected" coal-fired and nuclear-powered electrons build up at the "green filter" in each person's house and then overflow from the wires onto the ground. Not a lot of people know that it is the job of the meter reader to mop up all the spilled electrons every three months when he reads the meter.

[Scott]

Given the laws of photography - where each stop is a doubling of the light - will a 10% reduction in power output have any noticeable effect? (Or is the light output reduced by far more than 10%?)