Electricity - sense check
Discussion
ruggedscotty said:
Amazing what they will do to try and sell things....
How much were they charging for the device and what was the payback period. Ill bet that it was pretty lengthy.
Solar was making money through the feed in tariff. you were creating energy and putting it back to grid. This if it works gives very small reductions in consumed power but it also reduces the power by reducing the voltage as was explained very well earlier in the thread.
From my thread about 18 months ago...How much were they charging for the device and what was the payback period. Ill bet that it was pretty lengthy.
Solar was making money through the feed in tariff. you were creating energy and putting it back to grid. This if it works gives very small reductions in consumed power but it also reduces the power by reducing the voltage as was explained very well earlier in the thread.
S11Steve said:
This is a device that reduces the voltage from an indicated 244v at the sockets to 220v - saving us £x per year allegedly. Now I'd never heard of this before, so I was in no position to question or argue the physics behind it, but when he said they retail at £650 but they can install it for free as part of the deal I got itchy about the rest of their offerings.
Dr Mike Oxgreen said:
Edited to add: If they genuinely want to lower the amount of energy used by kettles, they should look into design changes to encourage people not to fill them more than necessary. Or perhaps limit the overall capacity so that people can’t boil excessive amounts for just one or two mugs of tea. Reducing the maximum size of kettles to somewhere between 1 and 1.5 litres would have a genuine environmental impact, because those morons who habitually fill to the brim would be boiling less water. You’ll never change that habit, IMHO.
This absolutely. The times a kettle is boiled with exactly the amount of water is probably miniscule compared to overfilling. Even if marginally. They should also improve the thermal insulation so they stay hotter longer. Edited by Dr Mike Oxgreen on Friday 23 February 07:31
I had one with a temperature setting which was great you could get it stop at 85/90/95c and then it would beep to tell you. It broke after a year though
Sheepshanks said:
Dr Mike Oxgreen said:
Whilst technically the UK voltage can legally go up to 110% of 230V (i.e. 253V) that is highly unlikely. I doubt it ever happens in practice. When I measure my mains voltage, I’ve never seen it more than a volt away from 240.
Ours routinely sits at 248V - we're in a biggish village, but some way away from the sub-station. Kettle boils quick!There was a fairly local company doing voltage optimisation - VPhase - but they went bust.
essayer said:
Ours went through a period of dropping to 218v during peak evening hours last summer. Didn’t notice any ill effects. I reported it to National Grid, who came to check and presumably fiddled with something, because it didn’t happen again after their visit.
The secret chemtrails factory down the road was causing a big draw on the local supply. The reptiles have made modifications now, but they will have Elvis and Diana keeping an eye on you........troublemaker
Dr Mike Oxgreen said:
Whilst technically the UK voltage can legally go up to 110% of 230V (i.e. 253V) that is highly unlikely. I doubt it ever happens in practice. When I measure my mains voltage, I’ve never seen it more than a volt away from 240.
As has been pointed out, “optimising” your voltage will have no effect on appliances that internally regulate their voltage and current. And on things like a kettle it just means that it takes longer to boil and uses exactly the same amount of energy*.
It happens more often than you might think. At my current place, it averages around 247 V and occasionally hits 254 V at weekends in Summer. At my last home, the voltage would gradually climb to 252 V overnight and then a voltage regulator would reset to a lower voltage setting knocking it down to about 246 V, before it would climb up to 252 V again, and the transformer would drop the voltage a 2nd time. Then when the voltage hit 240 V in the morning, the voltage regulator would kick back in bringing it back up to about 246 V.As has been pointed out, “optimising” your voltage will have no effect on appliances that internally regulate their voltage and current. And on things like a kettle it just means that it takes longer to boil and uses exactly the same amount of energy*.
Now that domestic solar PV is a thing, the reverse flow of power can result in dramatic increases in voltage. While out-of-the-box grid-connected solar systems are designed to shutdown if mains voltage reaches 253 V, in some parts of the country its common for installers to set the trip voltage to 260V or so, because at 253 V the number of trips and lost production is considered unacceptable by the customer.
A number of appliances do become less efficient at high voltages - things like motors (e.g. the compressor in your fridge/freezer), equipment using transformers for power supply rather than electronic voltage converters. In both cases, these things operate with magnetic fields, and the voltage is used to magnetise the device. However, if the voltage is too high for the amount of magnetic material, then energy wastage can increase drastically. This used to be very common with electronic widgets using the cheapest possible transformer bricks - at 250 V, these would often get so hot as to be uncomfortable to touch - no doubt being built to a price, the transformers had been built with barely enough magnetic material for 220-230 V, and at 250 V they would be struggling. These days with electronic voltage converters, it really isn't an issue.
In general, however, for domestic use the benefit of "voltage optimisation" is minimal. The energy consumption of motors, conventional transformers and magnetically regulated fluorescent lights is low as a proportion of the load.
Things are different for industry, where there is more to optimise than just reducing voltage (phase voltage balance, harmonic currents, etc.) and the amount of power consumed in things like motors where efficiency is sensitive to voltage, phase balance and harmonics, is significantly higher; and where the customer is expected to pay for things like peak power consumption, harmonics, power factor and various other things. It can also be useful if an industrial site threatens to outgrow its electricity supply, as the customer may be expected to fund the capital upgrades to the grid, and therefore there is a strong economic incentive to reduce energy consumption for as long as possible.
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