Economy 7

[SimonH2]

When there is a surplus (e.g. from baseload nuclear plants that are hard to 'turn down' at night-time) this is used to charge pumped storage. If there is surplus beyond that, I can imagine companies having arrangements* to increase usage to absorb that. And you refer to companies doing that. I have never heard of electricity companies simply giving power to domestic customers.

I assume he is referring to a scheme whereby the vendors of this snake oil will register the systems (in aggregate) as a dispatchable energy sink. Then if the grid needs to dump power, then it calls up the vendor who will remotely switch on as many customers systems as are called for, for as long as they are needed - and then divvy up the payments to the customers to offset their lecky bills.
But given that we are a very long way off having excess nuclear capacity - even at times of lowest demand and peak wind - I doubt that it's going to happen as often as the marketing types would like you to believe. There may be standing payments for having the capacity to do this - but I doubt that they will be significant by the time they have been divvied up down to individual households.

BTW - there is a company doing to reverse with standby generators. As long as your genny can be paralleled with the grid, they will add controls&comms so that they can remote start the genny to provide STOR (Short Term Operating Reserve) to the grid. You get standing payments for the capacity, plus further payments if it's called on. The company sells it one also allowing you to run your genny on full load periodically, as well as turning over your fuel supply so it doesn't get as stale as it would sat in the tank for years on end.

 

[hard-work]

It is not clear which video you are referring to as you have posted five but none were in the comment (#90) where you said "how much the grid gives you for free, or rock bottom priced electricity".

They are having a trial with 1,000s of Mixergy's right now with the National Grid, who will switch them on remotely to receive free or rock bottom priced electricity, when they have a surplus. They often produce a surplus. They pay companies to use the stuff when they produce too much of it. Very few people know that. Look at how the Mixergy works without the grid giving free electricity. That alone is an advance. It knows when the temperature is all down the side of the cylinder and will heat to whatever level down you choose - using a smart control system.

By the way, this snake oil cylinder was developed in conjunction with Oxford uni.

 

[JohnW2]

From that page I think the main advantage they are pushing is that you can use sources such as solar thermal, heat pumps, wood stoves or wind power to heat the water in the heat store and 'only' use gas/electricity when those are not sufficient.

Yes, I don't deny (and never would have denied) that systems such as we are discussing could make sense if there are significant contributions from non-mainline sources of energy - but that's not really what we've been discussing (or, at least, not what I thought we were discussing).

Kind Regards, John

 

[StephenOak]

I assume he is referring to a scheme whereby the vendors of this snake oil will register the systems (in aggregate) as a dispatchable energy sink.

I looked again and the first video in post #88 does talk about this, with a 'smart' tank only heating up what it thinks you need but heating more if the electricity price is low.

However, c. 10:30 in that video, the 'expert' says, "It's a future prospect, at the moment it's not done in a domestic setting". So that makes hard_work's comment (in post #90) that "Occasionally you will get out of bed to a full hot cylinder of water maybe for free" implying that this is a already happening
seem rather odd, to say the least.

But given that we are a very long way off having excess nuclear capacity

Oh indeed. There will rarely be a surplus to be dumped, I was just pointing out that even if there was it would not go to domestic customers.

 

[JohnW2]

With a thermal store or heat bank** - I've never ever heard them referred to as instantaneous water heaters ....

That is, of course, how I got into this discussion (since I've never heard of that being done, either), but it has spun off into discussion of all sorts of issues which I never really intended (or wanted) to discuss (or am necessarily knowledgeable or qualified enough to discuss!)!

Kind Regards, John

 

[hard-work]

http://www.newarkcoppercylinder.co.uk/mixergy-tank.html

The National Physical Labs tested it:
http://www.newarkcoppercylinder.co.uk/booklets/Mixergy_Statement of Verification_NPL_REDACTED.pdf

 

[JohnW2]

Actually I have done measurements and found a combi to have double the losses of the thermal store I put in the flat. It does depend on the combi and it's settings, but a combi will either have the "wait for ages for hot water" problem, or it will have high (higher than a storage tank ?) losses keeping itself warm. Measured standing losses on the thermal store in the flat were about 80W (measured over several days using the lecky meter), while the combi in the house next door had losses of around twice that with eco mode off.

I'm not sure that I fully understand that. What sort of 'combi losses' are you talking about - if, hypothetically, it was only providing DHW, it would only very rarely be 'on'. ... and what was heating your thermal store - cheap electricity?

Kind Regards, John

 

[StephenOak]

They are having a trial with 1,000s of Mixergy's right now with the National Grid, who will switch them on remotely to receive free or rock bottom priced electricity, when they have a surplus.

Well, as I said to SimonH, that very video says this is not available domestically.

Look at how the Mixergy works

It looks a very snake oil system to me. They say that all existing tanks have the heating element at the bottom and have to heat the whole tank before you can use hot water. In my experience the heating element(s) run along the long axis and any hot water rapidly rises to the top.

 

[JohnW2]

Electricity supply is varied to meet demand so there is rarely any surplus.

Quite, and I can't see how there could be, given that electricity is not stored (other than to a very small extent, 'hyro-electrically'.) (see below about nuclear). There will obviously be surplus generating capacity at times of low demand, but that is very different from 'surplus electricity'!

When there is a surplus (e.g. from baseload nuclear plants that are hard to 'turn down' at night-time) this is used to charge pumped storage.

Yes, but we have a National Grid, to which nuclear plants are a relatively small contributor. It would therefore only be in the (probably almost unthinkable) scenario in which the total demand on the grid was less that the total 'minimum output' of nuclear plants that they would end up with a true surplus of electricity 'which they had to get rid of'.

I have never heard of electricity companies simply giving power to domestic customers. How would they choose who to give it to? How would they even do it? If you consume X kWh overnight then your meter will go up by X.

Quite so!

Kind Regards, John

 

[StephenOak]

The video is clear they are trialling them with National Grid.

Really? Care to say where in the video it says this? At the end Kryten says that his new tank is part of a tax-payer funded scheme to study electricity usage, nothing there about National Grid, nor about people getting reduced price or free electricity.

And they are saying this is better than a normal one because it does not have a bottom element, when normal tanks don't have a bottom element. In logic that is a strawman argument, when someone is selling something it is clearly snake oil.

 

[hard-work]

electricity is not stored (other than to a very small extent, 'hyro-electrically'.

Tony Seba goes on about "peaker" power stations, and that none will be built. Interesting....

As the above video shows, Tesla built a grid battery storage facility to eliminate building a natural gas "peaker" power station in "88 days". It is a matter of running the existing generating stations at full capacity, or near to, and storing the surplus electricity to cope with peaks. Power stations tend to be at their maximum efficiency at near to or at full electricity generation.

Companies are paid to use electricity as at times too much is being generated. This surplus can be stored not wasted.

The head of National Grid in the UK said no more generating capacity needs to be built if the country went over to all EVs in a short time period. Petroleum refining uses a massive level of electricity to produce the fuels. This generation would simply transfer over to charging EVs directly.

It has been suggested that where practicable, government buildings, including schools, should incorporate solar panels, with all new buildings having them incorporated into the design, coupled to storage batteries. Here is a school that produced 'more' electricity than what it used.

"Turning homes into mini power stations could help reduce energy bills by more than 60 per cent, according to a new report."

"The concept has already been deployed on a building in Swansea, where an ‘Active Classroom’ combines integrated photovoltaics (PV) and battery storage with solar heat collection. Saltwater batteries can power the classroom for two days, and over six months of operation the building has produced more energy than it has used."

https://www.theengineer.co.uk/report...ower-stations/​

All this can easily be implemented quite quickly and quicker than building new 'peaker' power stations. It should result in the decommissioning of fossil fuel power stations.

It is all about storage, 'buffering'. The utilities of: water, gas and sewage have done this for a few hundred years to even out distribution flow. Electricity could only buffer using water, now batteries are capable of storing enough electricity for peak grid use . The UK has a few grid battery storage facilities. The latest facility was opened in Barrow.

 

[hard-work]

As it says a Gvmt dept is paying for the Mixergy trial (Robert Llewellyn says, the taxpayers), including National Grid on the trial. They would have to be to give free electricity.

 

[StephenOak]

Yes, but we have a National Grid, to which nuclear plants are a relatively small contributor.

Roughly 30%, so, IMO, not that small, http://www.gridwatch.templar.co.uk/.

It would therefore only be in the (probably almost unthinkable) scenario in which the total demand on the grid was less that the total 'minimum output' of nuclear plants that they would end up with a true surplus of electricity 'which they had to get rid of'.

In the video the chap talks about the wholesale price being set every 30 minutes and the smart system taking advantage of lower prices, rather than free electricity. Some times (maybe windy sunny days) there may be enough capacity to drive these down significantly but I doubt it will frequently drive them to below the cost of gas.

 

[StephenOak]

As it says a Gvmt dept is paying for the Mixergy trial (Robert Llewellyn says, the taxpayers), including National Grid on the trial.

I'll try once more. At what point in the video does it say that NG is involved?. At the end RL only mentions BEIS.

They would have to be to give free electricity.

And again here. At what point in the video does it say that NG is giving free electricity?

 

[hard-work]

If they are heating the whole of your cylinder for buttons, they can say fill it up, then it will most certainly compete with gas. Most modern blocks of flats do not even put gas in. The sale of induction hobs is rising to the point gas is only used for CH & DHW. In modern highly insulated homes the CH demand will be so low it is not worth installing gas heating, or gas at all. There is one installation expense gone. No mains pipes, ugly flues on the outside walls, meters and the lot. All gone.

I know a block of flats that was fitted with electric heating, just to be sure. In 5 years no one has ever turned on their CH. The heat loss is so low, with heat lost by one flat is gained by another. Solar gain and human body heat is enough to heat them in the UK winter.