Urban75 Home About Offline BrixtonBuzz Contact

Smart meters for energy

newbie said:
I misunderstood your post then, I thought autonomously meant local measurement. In the last couple of minutes it's jumped to 50.117 (the Dynamic one isn't quite the same as Gridwatch but that might be latency) so autonomous devices would flipflop on and off as the grid corrects the frequency by bringing gas turbines in and out.
Click to expand...
I think the ideas is that you use dynamic power management to control devices which are comparatively high-current, but which don't have to be on all the time - fridges being the canonical example. So you tweak the power curve on your fridge according to how high grid demand is, so that as demand goes up transiently, you tolerate your fridge temperature rising by a degree or two by modulating the compressor cycle, and then cool it back down again when demand drops by increasing the amount of time the compressor runs (so, effectively, having a "fine tune" temperature control based on grid load). I imagine the same could be done for other devices - battery chargers, even heating to some extent.
 
existentialist said:
The accuracy went up, or the sensed current? That'd make some sense, given that those meters do have big fuckoff coils in them! :)
Click to expand...
You're right of course, and so long as it was not moved it provided reliable comparative figures of unknown actual accuracy.
The current sensing shouldn't be the hard bit - I think the bigger faff would be interfacing it to some kind of WiFi, but maybe that'd be fairly straightforward with an Arduino type setup.

But yeah - why can't they just make the smartmeter output open? I imagine someone would crack the encryption pretty swiftly, in any case.
Click to expand...
I had an Arduino with optical sensor monitoring the old analogue meters, but haven't managed that with the SMETS1 meters. The data rate is tiny so wifi is power thirsty expensive overkill, the cheapest RF kits worked fine.

If the Zigbee gets cracked all the people worrying about privacy- burglars, growrooms, whatever- will be proven right and it's my data and I expect them to keep it secure but allow me to access it.
 
existentialist said:
I think the ideas is that you use dynamic power management to control devices which are comparatively high-current, but which don't have to be on all the time - fridges being the canonical example. So you tweak the power curve on your fridge according to how high grid demand is, so that as demand goes up transiently, you tolerate your fridge temperature rising by a degree or two by modulating the compressor cycle, and then cool it back down again when demand drops by increasing the amount of time the compressor runs (so, effectively, having a "fine tune" temperature control based on grid load). I imagine the same could be done for other devices - battery chargers, even heating to some extent.
Click to expand...
I see. When scaled across the population there's a potentially harmful feedback mechanism here isn't there?- when a new generator kicks in for its 15 minute slot there's suddenly a surplus of supply, leading to both a price drop and frequency increase, causing fridges across the land to kick in, which increases consumption pushing the price back up and frequency down, switching fridges off or more capacity in. By no means impossible to manage, but to scale so all consumers have equitable access to the cheapest power while overall Grid use is minimised will be an IT challenge.

In any event the utility has to bill each consumer, so unless all appliances report back their consumtpion, minute by minute, each household has to have a meter with timed tariff capability. If that's the case building autonomy into all devices, or even all fridges, and expecting consumers to somehow manage the connectivity, is a bit pointless when all they need to do is be slaved to on/off commands from the local meter.
 
newbie said:
I see. When scaled across the population there's a potentially harmful feedback mechanism here isn't there?- when a new generator kicks in for its 15 minute slot there's suddenly a surplus of supply, leading to both a price drop and frequency increase, causing fridges across the land to kick in, which increases consumption pushing the price back up and frequency down, switching fridges off or more capacity in. By no means impossible to manage, but to scale so all consumers have equitable access to the cheapest power while overall Grid use is minimised will be an IT challenge.

In any event the utility has to bill each consumer, so unless all appliances report back their consumtpion, minute by minute, each household has to have a meter with timed tariff capability. If that's the case building autonomy into all devices, or even all fridges, and expecting consumers to somehow manage the connectivity, is a bit pointless when all they need to do is be slaved to on/off commands from the local meter.
Click to expand...
Yes, I did wonder about that, although if it's devices like fridges which don't run continuously in any case, the impact is going to be rather less.

As for billing, I think the philosophy behind the approach was that, if demand was being managed dynamically, there'd be less need to control usage patterns via billing in the first place.

As ever, I suspect we'll end up with some provider-friendly centralised system that works, strangely, to the benefit of the generators far more than it does to that of the consumer, who, presumably, will end up footing the bill for the sub-optimal and probably rather expensive control gear necessary to manage demand. But that won't be anything new...
 
existentialist said:
I do wonder what that means, though. Unless there is some very subtle aspect to the way a smartmeter is operating, what it's essentially doing is monitoring the current flow through a pair of wires. There are other considerations - availability of mobile networks, and whether it can connect into your own wifi for the home energy monitor to work, but those are nothing to do with wiring :confused:
Click to expand...
I think it's bullshit, personally.

Problems with connecting to a mobile network aren't to do with hard wires, just the signal availability, sure?
 
equationgirl said:
I think it's bullshit, personally.

Problems with connecting to a mobile network aren't to do with hard wires, just the signal availability, sure?
Click to expand...
Exactly.

I must confess that I don't think the profession of electrician covers itself in glory a lot of the time. There seems to be a level of fear mongering around the subject that you don't get with the other trades to nearly the same extent. And yes, I know that the potential dangers of electricity are manifest and can be serious, but that doesn't excuse this kind of bullshit.

And I've seen too many supposedly-professional electrical installations where silly corners have been cut, or (conversely) expensive solutions installed to have a great deal of faith in the profession's integrity overall. I know there are good electricians, and I've even worked with a few, but it seems to be rather more generously provisioned with cowboys than is ideal...
 
planetgeli said:
Can my energy company force me to have a smart meter installed? A quick google doesn't seem to throw up a definitive answer beyond 'all households are going to get one by 2019'.

I'm not sure I want my energy company knowing every cup of tea I drink. Any answers?
Click to expand...

No, they can't. The chap who fitted one at my daughter's previous (rented) house said that they were a pain, and he wouldn't be having one himself.

We are about as energy conscious as you can get, the usage for the same period the previous year is usually down a bit. All our lights are LED, we use heat sparingly, that's what fleeces are for, and we don't waste hot water.
 
Sasaferrato said:
No, they can't. The chap who fitted one at my daughter's previous (rented) house said that they were a pain, and he wouldn't be having one himself.

We are about as energy conscious as you can get, the usage for the same period the previous year is usually down a bit. All our lights are LED, we use heat sparingly, that's what fleeces are for, and we don't waste hot water.
Click to expand...

You're Scottish, Sas. All those words to demonstrate your tight-fistedness are just tautological ;)
 
existentialist said:
I have no idea, only that it's a reasonably good approximation of generator load.
Click to expand...

newbie said:
I'm not sure either but I've read that controlling power factor (reactive/capacitive apparent load) is a major part of grid management and one of the reasons for distributed smart metering rather than doing it from the centre.

Gridwatch is currently showing 49.917Hz. As all the generator sets have to be in sync (don't they?) I'm not sure I see why your measurement or mine might be different: if it is, is that down to local pf or something else?
Click to expand...

Frequency response is coming to be a problem. In the past we got our electricity from about 100/150 big thermal generating sets in about 60 power stations. Basically boil water ( with coal or uranium) and use it to spin many thousands of tons of metal at 3000 rpm to make 50hz, all the generator sets ran snchronysed * . Even when we went to gas ( open or combined cycle) you still had hundreds of tons of metal spinning round at 3000 rpm. All that spinning metal has a huge amount of intertia, which is just another word for stored energy. If there was no intertia then as you increase the load on a generator, if you didn’t add more steam, it would slow down, if you reduced load it would speed up. The spinning intertia prevented this happening too quickly and stabilised the network to a time scale of seconds so that you could turn the steam up or down . Estimates vary but there was probably the equivalent of 4 to 8 powestations of output in that spinning metal inertia. The inertia came ‘free’ as part of the network.

Now, wind ( because of gearbox limitations) , solar and most interconnector cables are DC with inverters and have no inertia, their frequency really can change instantaneously. This is a problem both in an of itself in balencing the network and even more of a problem because lots of small scale (renewable and not) distribution side generation takes its safety cut off from the rate of frequency change. It sees a fast change as a disconnect and shuts down for safety. So we have a bit of a vicious circle - more load comes on the system- the frequency drops faster than in the past- lots of our generation sees this drop as a fault and switches off- the frequency drops even more. This has already caused blackouts.

Synthetic inertia is the solution, either physical flywheels - they have these at Culham already to Power JET without crashing the grid- or remote electronic synchronisation of the inverters, which doesn’t really work yet. Both are expensive and we will have to pay for them somehow- well through our bills- but it’s vital to enable us to get more renewables on the system.

* This is not strictly true, there is the dark magic of reactive power- which is why you need a power station in Cornwall that doesn’t really generate power and other weirdness- where one of the solutions is to run local generation sets slightly off frequency phase. This doesn’t really effect the grid frequency . This is also something that came mostly free with big spinning thermal sets and we will have to address- although the Scandinavians already have a solution.
 
Last edited:
A380 said:
...all the generator sets ran snchronysed *

-snip-

* This is not strictly true
Click to expand...

I'm going to stick my neck out and say they are synchronised but just necessarily in phase. But I freely admit that I'm no expert in the generation or distribution.

One of the perks of having worked on the supply side were the occasional meetings held at power stations where you'd sometimes get all-area access (accompanied, natch) and meet the properly clever people who actually understood how things really worked.
 
a_chap said:
I'm going to stick my neck out and say they are synchronised but just necessarily in phase. But I freely admit that I'm no expert in the generation or distribution.

One of the perks of having worked on the supply side were the occasional meetings held at power stations where you'd sometimes get all-area access (accompanied, natch) and meet the properly clever people who actually understood how things really worked.
Click to expand...
It’s not even that straightforward...

But yes, I get to go to quite a lot of different power stations and they are all interesting places with fascinating people. Or perhaps that says more about me...
 
a_chap said:
I'm going to stick my neck out and say they are synchronised but just necessarily in phase. But I freely admit that I'm no expert in the generation or distribution.

One of the perks of having worked on the supply side were the occasional meetings held at power stations where you'd sometimes get all-area access (accompanied, natch) and meet the properly clever people who actually understood how things really worked.
Click to expand...

My late uncle Alec was the grid controller back in the day. His job was to keep input and output balanced and in phase.
 
a_chap said:
I'm going to stick my neck out and say they are synchronised but just necessarily in phase. But I freely admit that I'm no expert in the generation or distribution.

One of the perks of having worked on the supply side were the occasional meetings held at power stations where you'd sometimes get all-area access (accompanied, natch) and meet the properly clever people who actually understood how things really worked.
Click to expand...
No,, they have to be in phase, or they're pushing back against the grid (which, if they're only slightly out of phase, will drag them back in).
 
existentialist said:
No,, they have to be in phase, or they're pushing back against the grid (which, if they're only slightly out of phase, will drag them back in).
Click to expand...

Part of what happens is they are deliberately run out of phase to dampen down noise mostly from big inductors like factories with huge electric motors and railways. If it didn’t happen you’d get overheating in many components which wastes energy and can age the components. It‘s more than that though, The analogies most often used to describe and think about electricity break down here.
 
Last edited:
A380 said:
Part of what happens is they are deliberately run out of phase to dampen down noise mostly from big inductors like factories with huge electric motors and railways. If it didn’t happen you’d get overheating in many components which wastes energy and can age the components. It‘s more than that though, The analogies most often used to describe and think about electricity break down here.
Click to expand...
OK, yeah, this inductive load is where my electrical knowledge breaks down and runs out at the corners... :)
 
Fuck smart meters. There are supposed to be some that are accessible in terms of you can link them to your smart phone read them. But the electric companies know fuck all about them it’s not for customers benefit.
 
It’s hardly rocket science come on they should have them already. But no different standards fucking bullshit
 
A380 said:
there is the dark magic of reactive power- which is why you need a power station in Cornwall that doesn’t really generate power and other weirdness
Click to expand...

fascinating, can you give some more detail please, the internet is almost silent. Does this inject or absorb reactive power? Or both. And why put it in Cornwall, distant from bulk generation? Or does the grid have a single instantaneous power factor, with no geographic variation?

Now, wind ( because of gearbox limitations) , solar and most interconnector cables are DC with inverters and have no inertia, their frequency really can change instantaneously. This is a problem both in an of itself in balencing the network and even more of a problem because lots of small scale (renewable and not) distribution side generation takes its safety cut off from the rate of frequency change. It sees a fast change as a disconnect and shuts down for safety. So we have a bit of a vicious circle - more load comes on the system- the frequency drops faster than in the past- lots of our generation sees this drop as a fault and switches off- the frequency drops even more. This has already caused blackouts.
Click to expand...
This makes each inverter sound both autonomous and dumb. Which must have been the case historically, but is there a present or future arrangement involving networked interconnection and AI prediction to maintain clock frequency, which will scale to allow mass participation in supplying a smart grid via more widespread solar take-up and EV batteries?

TBH this has exposed my shaky understanding and raised far more questions than I can answer. Do you know of a reasonably concise dummies guide to grid frequency control?
 
newbie said:
fascinating, can you give some more detail please, the internet is almost silent. Does this inject or absorb reactive power? Or both. And why put it in Cornwall, distant from bulk generation? Or does the grid have a single instantaneous power factor, with no geographic variation?


This makes each inverter sound both autonomous and dumb. Which must have been the case historically, but is there a present or future arrangement involving networked interconnection and AI prediction to maintain clock frequency, which will scale to allow mass participation in supplying a smart grid via more widespread solar take-up and EV batteries?

TBH this has exposed my shaky understanding and raised far more questions than I can answer. Do you know of a reasonably concise dummies guide to grid frequency control?
Click to expand...

There is a book call electricity for dummies but I’ve not seen it in electronic copy and the hard copies look like it was a vanity type publication for one of the training consultancies.

The reason for the Cornish site was that it was so far from any big plant in the past ( the Nuclear plant at Hinckley was I think the nearest) so the system needed something down there. As the reactive power effects, unlike energy, are distance limited ( 50 /60 miles?)

In terms of frequency response Smart inverters may be the way forward, batteries ( stand alone, hybrid or EVs as you say) will probably play apart.

If you are interested this report phrases a lot of the questions about how we transition to a de carbonised electricity system. Don’t expect all the answers though.

https://www.gov.uk/government/uploa...nt_data/file/654902/Cost_of_Energy_Review.pdf
 
A380 said:
The reason for the Cornish site was that it was so far from any big plant in the past ( the Nuclear plant at Hinckley was I think the nearest) so the system needed something down there.
Click to expand...
There's apparently a CCGT in Plymouth and small
hydro plants in Devon/Cornwall- coincidentally I visited one at Morwellham a few weeks ago, built in the 30s to utilise watercourses dug for previous generations of mining. That's not mentioned on the wiki list, nor is the one you mention- do you have a name?

As the reactive power effects, unlike energy, are distance limited ( 50 /60 miles?)
Click to expand...
ooh, tantalising, I really want a better grasp of how this all works!

Thanks for the sources, I'll have a look. I've been trying to make sense of this, but it's a bit too detailed and doesn't quite explain enough for background understanding.
 
A380 said:
It’s not even that straightforward...

But yes, I get to go to quite a lot of different power stations and they are all interesting places with fascinating people. Or perhaps that says more about me...
Click to expand...
Power stations are fascinating, really. Probably why I ended up in the energy sector. Not a distribution expert by any means but moving to a different type of generation without the inertia component shows where the grid itself has issues. Upgrading it will be a huge task, but necessary for energy storage and more renewables.
 
Isn't Germany paving the way here (and doing all the expensive research) with Energiewende?
 
newbie said:
There's apparently a CCGT in Plymouth and small
hydro plants in Devon/Cornwall- coincidentally I visited one at Morwellham a few weeks ago, built in the 30s to utilise watercourses dug for previous generations of mining. That's not mentioned on the wiki list, nor is the one you mention- do you have a name?


ooh, tantalising, I really want a better grasp of how this all works!

Thanks for the sources, I'll have a look. I've been trying to make sense of this, but it's a bit too detailed and doesn't quite explain enough for background understanding.
Click to expand...
It was called Indian Queens and was oil fired. I think there may still be a small gas or oil one on the same site, but that’s more a conventional peaking plant. Now you have more distribution side generation down there they can do it with less.
 
a_chap said:
Isn't Germany paving the way here (and doing all the expensive research) with Energiewende?
Click to expand...
Every developed country is facing the same as we move away from big coal and nuke transmission side generation to renewables both big and small via gas combined cycle. Still in 40 years time fusion will be here and we’ll have to turn it all back again....
 
You must log in or register to reply here.

Similar threads

UnderOpenSky
Has anyone switched to a Tracker plan for energy?
Replies
1
Views
198
8ball
8ball
AnnaKarpik
Does this energy monitor exist?
Replies
11
Views
451
newbie
newbie
bimble
What is ‘smart casual’ for women
2 3
Replies
69
Views
2K
newme
newme
panpete
Energy tariffs
Replies
4
Views
269
panpete
panpete
Steel Icarus
Household lights and saving energy
Replies
26
Views
1K
teuchter
teuchter
Back
Top Bottom