Electricity Smart Meter

[TimC]

I'd love to fit an ASHP for my house, but it's a listed building so The Powers That Be won't let me, and it has no wet central heating anyway. It was all (well, four rooms) storage heating, but I replaced those with modern electric clay-cored heaters. I still have an Economy 7 meter ('cos water heating), and that apparently prevents the fitting of a Smart Meter. So, despite being smaller than the average snail's shell (ok, exaggeration - it's 780 sq ft), the leccy bills are around £200 a month.

[SteveC]

Back in the '70s, when storage heaters were all the rage, my dad used to work for the CEGB, which meant he was sometimes in the Grid Control Centre. Apparently, those heaters needed a top-up during the day, so they came on a 2.00 pm for half an hour or so. All of them. All across the country. And bringing generators on line in those days was still a largely manual process. Visitors were not popular from about 1.50 onwards.

[Cudzoziemiec]

Can someone explain to me the physics of heat pumps? In terms simple enough to be understood by someone who got a C* in O-level physics way back in the 80s. How does the air or ground at a few degrees C transfer heat to a room that's warmer than that?

*Might have been a B, can't remember.

[Feanor]

Same way that a fridge moves heat out of the inside which is cooler, into the room which is warmer.

Think of it as a fridge trying to cool the outside air down even lower.
The extracted heat is dumped inside the house,  just the same as the fridge dumps the extracted heat into the room via the warm part at the back.

[Cudzoziemiec]

So evaporation and condensation? But in this case condensing or compressing inside the building.

[grams]

Pull your fridge away from the wall. The tubing on the back is nice and hot. That tubing emits much more heat than the number of watts going into the motor, because most of it is heat extracted from inside the cabinet.

Now stick your fridge on the window cill so the tubing is facing you and the door is open to the outside world. That's an air source heat pump.

[Cudzoziemiec]

Clear. Thanks. 

[rob]

Back in the '70s, when storage heaters were all the rage, my dad used to work for the CEGB, which meant he was sometimes in the Grid Control Centre. Apparently, those heaters needed a top-up during the day, so they came on a 2.00 pm for half an hour or so. All of them. All across the country. And bringing generators on line in those days was still a largely manual process. Visitors were not popular from about 1.50 onwards.

These days that would help Grid out.  There are times if day particularly when it’s windy that they are looking to turn demand up.  You could end up with a situation where you could be paid to consume power, which brings us neatly back to the benefits of smart meters.

[cygnet]

Bunhill and Citigen aslo provide district heating in the Farringdon/Barbican/Old St area

I used to look after the Citigen contract when I worked for London Electricity 20 years ago.

Were they running the submarine engines then? I had brief involvement as some of the heating/cooling pipes ran across a site I worked on.

[quixoticgeek]

So evaporation and condensation? But in this case condensing or compressing inside the building.

Yep, it's all based on the fact that compressing something makes it hot, and lowing the pressure makes it cold. (When i was diving, if you ever cracked a valve to empty a tank that had the wrong mix in it, the whole valve would ice up).

an air con unit is an air source heat pump, it's just rigged the wrong way round, if you put the inside unit outside, and the outside unit inside, you would have a very crude, very inefficient, air source heat pump...

There's some useful videos on gootube that explain it with really nice animations that explain it well...

J

[rob]

Bunhill and Citigen aslo provide district heating in the Farringdon/Barbican/Old St area

I used to look after the Citigen contract when I worked for London Electricity 20 years ago.

Were they running the submarine engines then? I had brief involvement as some of the heating/cooling pipes ran across a site I worked on.

I just did the settlement for the power offtake and looked at the balancing.  Annoyingly I didn’t get a site visit with that deal.

[Diver300]

an air con unit is an air source heat pump, it's just rigged the wrong way round, if you put the inside unit outside, and the outside unit inside, you would have a very crude, very inefficient, air source heat pump...

Point of order / physics. If you rig an air con unit the wrong way round, you get a perfectly good air source heat pump. It would be just about as efficient as any. With a split aircon system the outside unit and the inside unit look different because, well, one goes outside and the other goes inside, but they do the same / opposite jobs of boiling / condensing the fluid and losing / gaining heat to the air. There's a compressor somewhere, usually the outside unit because of noise, but it could be anywhere really.

Many aircon units can swap the heating / cooling between inside and outside units. A couple of solenoid valves does the job a lot more easily than taking out a chunk of wall and turning it round, but the effect on the heat flows is much the same.

Most heat pumps can't cool, because if you try to cool using radiators you get condensation on the radiators. Cooling has to be by air, so the actual radiator / evaporator can be where the condensation can be piped away.

[quixoticgeek]

Point of order / physics. If you rig an air con unit the wrong way round, you get a perfectly good air source heat pump. It would be just about as efficient as any. With a split aircon system the outside unit and the inside unit look different because, well, one goes outside and the other goes inside, but they do the same / opposite jobs of boiling / condensing the fluid and losing / gaining heat to the air. There's a compressor somewhere, usually the outside unit because of noise, but it could be anywhere really.

I was thinking more from the fact that the the hot side wouldn't be very good at heating the space, because of the compactness of the unit.

J

[Diver300]

Point of order / physics. If you rig an air con unit the wrong way round, you get a perfectly good air source heat pump. It would be just about as efficient as any. With a split aircon system the outside unit and the inside unit look different because, well, one goes outside and the other goes inside, but they do the same / opposite jobs of boiling / condensing the fluid and losing / gaining heat to the air. There's a compressor somewhere, usually the outside unit because of noise, but it could be anywhere really.

I was thinking more from the fact that the the hot side wouldn't be very good at heating the space, because of the compactness of the unit.

J

All the aircon units that I have seen have had similar sized inside and outside units, or the inside unit is a bit smaller because of aesthetics. As the heat flow are much the same for both units and both are exchanging heat to air blow by a fan, it would be strange to have very different sizes.

[perpetual dan]

We used to have district heating in some parts of London. Back in the mists of time, my Mum worked for the council housing department and they had blocks that were heated from the local power station.

Churchill Gardens in Pimlico used to be heated by waste heat from Battersea power station. There's a tunnel under the river for the pipes. When the power station was shut down a boiler house was built, on the south side of the river, to heat the estate, on the north side.

Here's the hot water tank

That’s quite possibly where she was talking about.

[Wombat]

My electricity meter, which was installed when the house was built in 1985, ran backwards for quite a while, when we generated plenty of solar PV.  Our suppliers were of course, told of the type of meter, before the PV was installed, as part of the application for feed-in tariff.  However they chose to ignore this, and then got arsey over my bills.  Well sorry mates, but you were given the opportunity to change it!  I was being awkward and saying you can't change it unless its a smart meter, but we both new that wouldn't hold water.  They did eventually change it, but the haggling over consumption dragged on a bit.

In other news, I have another appointment for installation of a smart meter, on 16th November.  Apparently the first thing he will insist on doing before he installs it, is turn off the gas.  That could take him a while, as there's no gas for quite a few miles from here!  What he might be better advised to do, is ask me to turn off the PV, if he doesn't want to be electrocuted.  We will probably then have the conversation around "oh, you've got PV, we can't install it", and "Oh, we can't get a data signal".  Well that's your effing problem, I've made 3 formal complaints to you about it, so bleedin' well sort it!

I'm stunned!

I actually have a working smart meter.  And it actually obliges and the display says "0W"  (yes, that's a zero, not the meter saying OW!") when we're generating more than we're consuming.  Of course the export meter does tell the truth as well, so we get our feed-in tariff payments.  So, what was so bloody difficult, and why the zillions of excuses as to why they couldn't fit one?

[ian]

Our smart meter installation is tomorrow. I am somehow managing to keep a lid on my excitement. I gave up asking them if the cupboard was too small or what kind of meter it was and subjugated myself to the endless hectoring. I started to feel like I was spoiling their party.

[ian]

Mostly painless, the Asbestos Palace is now smart metered. Apparently, our gas meter was unsupported (literally, it was levitating on gas pipes alone, which is against the regulations, so had to be re-mangled into a more statutorily acceptable format).

I am currently running up an electricity bill at 6p per hour. Oh my.

[robgul]

Mostly painless, the Asbestos Palace is now smart metered. Apparently, our gas meter was unsupported (literally, it was levitating on gas pipes alone, which is against the regulations, so had to be re-mangled into a more statutorily acceptable format).

I am currently running up an electricity bill at 6p per hour. Oh my.

.... you'll soon get bored with the usage indicator gadget  . . .   two weeks max and you'll disconnect it

[ian]

Up to 7p/h now. This wouldn't matter if we all had our own home nuclear power generators.

[rob]

Up to 7p/h now. This wouldn't matter if we all had our own home nuclear power generators.

You probably haven’t picked the right time of year to start tracking the data.   Energy usage can be next to nothing in the Summer months.

[Canardly]

Up to 7p/h now. This wouldn't matter if we all had our own home nuclear power generators.

Dont put the kettle on, you will start screaming.

[Feanor]

Yes, the electric thing is all instantaneous noise.

Shove the kettle on and it's all Alarums and Excursions.
What response is expected? Turn off the kettle?

I sometimes try to goad it from green to orange to red.

[Kim]

They would be a lot more useful if they plotted a graph.  Otherwise it just tells you what you know already, and what state your fridge's thermostat is in.  Instantaneous power is useful if you're going round switching things off to find a mysterious load, but a plug-in power meter is usually a more convenient^[1] way of measuring that.


_{[1] Except for the things that don't have plugs.}

[Kim]

Did I mention the comedy email from the Cephalopod?

Between 4:30pm – 6:30pm today, National Grid will be paying fossil fuel generators as much as 10 times the normal price for electricity to meet high demand.

We'd rather just pay to help you use less. That way the money goes to our customers, and National Grid don’t use as much fossil fuels.

So we’re running a special trial — and you're invited.

If you can reduce your electricity use between 4:30pm – 6:30pm today to half of your normal amount or less, any energy you do use will be completely free.

You normally use 1.2kWh between 4:30pm – 6:30pm on a Thursday, so use 0.6kWh or less to earn your free energy, and help ditch fossil fuels.

That's right!  Cut our use to below 300W for that period and win 7.3p worth of electrons absolutely free!!!

I tried to do it, purely for SCIENCE, and almost but didn't quite manage it.  I'm blaming barakta's ork laptop which has some errant security software that likes to spin in a loop to give the fans something to do.

Unexpected result:

Thanks for joining in our big switch off, with thousands of other Octopus Energy customers.

Our boffins have tabulated and reviewed all the numbers.

In one or two cases, we weren’t able to access meter readings in time to be included in the calculations. Your meter was one of these, but we still appreciate you getting involved — so we’re crediting your account with £1: the average credit earned by all participants. We’ll apply the credit to your account within 7 days.

So what were the results of the trial? In short: a lot.

Firstly, due to factors like the cold weather and the start of lockdown, 2 out of 3 customers who weren’t involved in the trial actually used more than their average Thursday during the trial period.

And yet 2 out of 3 customers in our smart trial used less than their average: a fantastic result.

The individual amounts weren’t large — around half a kWh — but across thousands of homes make a big difference. In fact, if we scaled up the results to all Octopus customers, that small contribution from each home would have accounted for 3/4 of the entire National Grid shortfall.

Maybe they're just really bad at computers?  I can get our readings from their API within 24 hours.  *boggle*