Economy 7

[hard-work]

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.

The other guy does half mention National Grid then clips it and says anyone you like.

 

[hard-work]

Things are changing big time all around you and you are oblivious of it.

 

[hard-work]

 

[hard-work]

Britain's National Grid to pay firms to use power this summer
https://uk.reuters.com/article/uk-b...-firms-to-use-power-this-summer-idUKKCN0XI1P2

National Grid is gearing up for summer with the start of a scheme which pays companies to use more electricity when wind and solar power surges past demand.
https://www.telegraph.co.uk/busines...-grid-prepares-summer-excess-calls-use-power/

 

[JohnW2]

Roughly 30%, so, IMO, not that small

Fair enough (I would have guess somewhat lower than that). However, that is at 'running level' , and I presume that the minimum 'safe' nuclear output is far less than that. In any event, the gridwatch graphs seem to indicate that (at 'running' levels), the nuclear contribution is never more than about 8 GW and the demand on the grid never under 20 GW - so there is absolutely no chance of even the 'running' nuclear output, let alone the 'minimum safe' nuclear output, could exceed demand - unless things change dramatically.

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.

Agreed. Mind you, unless something (e.g. regulators or competition) forced suppliers to do do, I'm far from convinced that they would necessarily 'pass' on low costs on an hour-by-hour basis. However, there are obviously two sides to that coin, and one of the very things that those opposed to 'smart' meters most fear is that very high prices will be 'passed on' to them during the peaks of that hour-by-hour variation in wholesale price.

The concept of adjusting price dynamically on the basis of changes the supply/demand situation is, of course, questionable in many people's minds in relation to such a basic ('essential') commodity as fuel. It presumably costs little, if anything, more to produce electricity when demand is high in relation to supply, so such a system could presumably only be justified if it resulted in changes of usage patterns which were beneficial to the network (hence preserving customer's supplies) - and I'm not sure that people would be vigilant enough in monitoring hour-by-hour changes in the price of electricity for that to be very effectively - at least, in the short term.

Kind Regards, John

 

[ericmark]

I have worked on many power stations and the Sizewell 'B' had two 750 Mw generators plus I think 10 diesel generators of 1.5 Mw each. Connah's Quay had four 600 Mw generators and Longannet power station had a row of generators can't remember how many 2,400 Mw OK that has closed now, but the point is counting the power stations does not work as the nuclear ones had rather a low output.

However this has nothing to do with using Economy 7 in a flat. I would agree the Gledhill non pressurised storage tanks need less maintenance, and still give hot water at cold water pressure. Also we fitted a power shower in mothers house because the hot water pressure was low and upstairs a shower would not work, however the RCD tripped supplying the power shower downstairs and no one noticed.

Great that industry is using excess power, however that has always been the case, my dad retired around 1985, and I remember him talking about exporting and importing power from where he worked to national grid, they were charged for peak power used during peak time, not how much they used. And the steelworks did use a lot of power.

However this does not help the flat owner, I still say Economy 7 is unlikely to break even within 10 years and by then there will be likely different tariffs anyway, I note were I live where an estuary becomes a river, the wind is tidal, so even the wind farms are tidal in output, and solar panels only produce in the day, so it is likely tariffs will change. Being able to use off peak power great, but only any good if off peak power is on sale to your home, and that's the rub, to spend £1000's setting it all up, only to find cheap fuel no longer sold is really going to be a kick in the teeth.

My dad had coke fired fires all though the house, massive bunker in back garden to store coke as minimum order was a ton, it would be poured on pavement and as a boy I would have to move it to back of house, however when the steelworks closed, so the supply of coke ended, so all coke fires removed, cooking moved to electric and heating to gas. Coke bunkers dismantled etc. Every one was same, so could not sell all the fires, they were scrap.

Solar panels OK the government guaranteed 25 years, but off peak power has no guarantee, it's a lot of money to take a chance with.

 

[StephenOak]

The other guy does half mention National Grid then clips it and says anyone you like.

So yet again you don't say when in the video this is. And you completely ignored my question about when in the video it says that NG is giving free electricity.

It seems there is little point in trying to get useful information from you.

 

[StephenOak]

so there is absolutely no chance of even the 'running' nuclear output, let alone the 'minimum safe' nuclear output, could exceed demand

I did originally mention the nuclear fleet (as they are always on) but in my previous post I (perhaps obliquely) clarified this by talking about windy sunny days being times when there is surplus capacity.

I know there have been times when wind farms have been paid (handsomely) to not supply electricity (constraint payments IIRC) because there was excess supply. Of course the payments are an artifact of the regulatory system whereby the output of wind / solar electricity producers has to be bought in preference to reliable sources. Nonetheless, there was more supply than demand.

unless something (e.g. regulators or competition) forced suppliers to do do, I'm far from convinced that they would necessarily 'pass' on low costs on an hour-by-hour basis

Indeed. I was merely pointing out that the idea of free electricity is (as far as I can see) something that has no foundation. All that hard_work's source was saying was that electricity might be less expensive, as opposed to cheap, some of the time.

However, there are obviously two sides to that coin, and one of the very things that those opposed to 'smart' meters most fear is that very high prices will be 'passed on' to them during the peaks of that hour-by-hour variation in wholesale price.

Someone (you?) has pointed out that such price switching needs 'smart' devices as well as 'smart' meters. This HW system is an example of such a smart device.

It presumably costs little, if anything, more to produce electricity when demand is high in relation to supply,

I'm not sure. Dips in supply (from solar / wind) are mostly covered by CCGT generators. However when they start up the GT part works immediately but the steam turbine takes time to get up to working temperature, 10-30 minutes from what I have read. As the dips can easily be shorter than this time the steam turbine never gets up to temperature. In that case the system is not operating as a CCGT (55-60% efficient) but as an OCGT (c. 35% efficient).

I have also heard that there are now a lot more diesel generators attached to the grid, used for covering smaller dips.

Also, if you look for information on electricity wholesale prices, e.g.
http://www.wrap.org.uk/content/electricity-spot-prices
you will see that there is quite a bit of variation, and some of that must come from varying costs of generation.

I'm not sure that people would be vigilant enough in monitoring hour-by-hour changes in the price of electricity for that to be very effectively

Very few people would be, hence a smart device.

 

[hard-work]

You have been overwhelmed by information from me you just did not know. You are now hung up for whatever reasons bounce around your mind, on a tiny point. I could look at the vid again, but please do it yourself. I am not lowering myself to your pettiness.

 

[StephenOak]

I am not lowering myself to your pettiness.

When someone has no reasoned point to make they resort to personal abuse.

 

[JohnW2]

It seems there is little point in trying to get useful information from you.

There presumably has to be a reason why he is called "hard-work".

Kind Regards, John

 

[SimonH2]

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'.

IIRC from what you've written you don't have a combi, so probably aren't familiar with some of their drawbacks. There are two modes they can run in, some have this as a setting (eg "eco mode").

• Just stay off when no demand (eco mode on). Little by way of standing loss, BUT there is a considerable delay between turning on a hot tap and getting hot water while the boiler fires up, heats up the primary loop, heats up the DHW heat exchanger, and eventually hot water comes out. This can amount to several gallons of wasted water and (I've timed it !) over a minute waiting.
• Stay hot (eco mode off). In this mode, they fire up from time to time to reheat the DHW heat exchanger and primary loop within the boiler. As little is lagged, and there's a great high capacity water-air heat exchanger, standing losses are not as low as you might imagine. From the use PoV, this means much quicker hot water.

Note that to reduce the water (and energy) wastage in eco mode, there is even a thermostatic valve available - Combisave. It's fitted as close as possible to the boiler DHW outlet and restricts the flow rate until the water is up to something like 40˚C - thus allowing enough flow to turn on the boiler, but restricting the flow to minimise water wastage and allow quicker heatup.

... and what was heating your thermal store - cheap electricity?

Normally gas, but the immersion is there for backup. For the purposes of the test, I ran it on electric only, allowing it several days to settle and then several days for measurement - just reading the meter several days apart and doing "energy used / time" to get an average for standing losses.

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.

Hmm, I take that with a large pinch of salt. Have a citation ?

Petroleum refining uses a massive level of electricity to produce the fuels. This generation would simply transfer over to charging EVs directly.

You don't have to be a rocket scientist to see the flaws in that argument. If it were so, then there would be no point extracting oil from the ground as there's be no net energy production from it. So I call bull manure on that one

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.

Yes, that is technically possible today - at what cost, both capital and running since batteries do not have indefinite life ?

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.

Yes, and presumably you realise how easy it is to store water - you can just pour it into a bucket and hold it. Perhaps you are aware of the old "lets play a trick on the new apprentice" one of telling them to go to the stores for a bucket of electricity

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.

I'm familiar with the one in Barrow - it's there because the company owned a site (Roosecote) that used to be a coal fired plant, then a gas fired plant, and then vacant. As such, they owned the land and it already had good connections (132kV lines) to the grid. What you conveniently overlook is it's capability - 43MW for 30 minutes. In terms of "storage" it really is (as the old adage goes) not even peeing in the ocean.
Lets look at those figures in a bit more detail. It's something in the order of 1000th (0.1%) of UK lecky usage for just 30 minutes. So a thousand of those plants to get grid backup for 30 minutes, fifty thousand of them to get 1 day - actually quite a few more to cover winter usage.
And it is not actually built for that - because it would not be worthwhile. It is there for second by second load balancing - ie frequency stabilisation. Eg, when there's a lull in the wind and wind generation drops almost instantaneously with a corresponding drop in grid frequency, this plant can output a few tens of MW to compensate; when the wind picks up, it can recharge. I forget the capital and running costs quoted for the plant but "inexpensive" is not an adjective that can be levelled at it One of the hidden costs of intermittent generation sources that the wind lobby like to ignore
For large scale electricity storage, there is nothing yet that can beat pumped storage - but we've already used about every site in the UK that could politically be used. There are plenty more, but it would be career suicide for any politician to suggest them - looking locally there's a few nice large lakes (such as Windermere) that would be fairly easy to dam up at the exit, but the shores are owned by a lot of fairly wealthy people who would "not be amused" at the suggestion

I'd suggest that Hard Work is a bit overwhelmed by finding an audience that understands the engineering and physics (ye cannae defy the laws of physics, captn) and isn't taken in by the jam tomorrow (maybe, if everything slots into place) snake oil he is pushing. As far as I can tell from what he's posted, all this "magical" product is :

• An electrically heated thermal store - nothing new
• A diffuser in the cold inlet to help with stratification - nothing new
• Some "smart" logic to control how much is heated - yeah great, the supplier turns off the server and your investment stops working (properly or at all, depends on whether there's any local over-rides available)*
• A suggestion that if many things (political, market, and technical) all drop into place then you might get some cheap(er) lecky, some time in the indeterminate future.

* Ask Zune or Revolv owners what that's like. But this isn't a "cheap" consumer electronics product, it's a long term investment. Anything that relies on a continued internet service for continued operation (or in this case, economical operation) is hostage to the whims and solvency of the vendor

And citing Tesla Powerwall as an example of large scale lecky storage is dodgy at best. Elon Musk is a top grade snake oil salesman, and from what I've read, the Powerwall relies (at least partially) on using used batteries from EVs - like that's going to scale well. Also, AIUI, he's yet to make a profit from selling high priced "show" cars to wealthy people with a statement to make and who don't mind having a car that's going to try and kill them, or at the very least drive under an "invisible" fire engine.

 

[JohnW2]

I know there have been times when wind farms have been paid (handsomely) to not supply electricity (constraint payments IIRC) because there was excess supply. Of course the payments are an artifact of the regulatory system whereby the output of wind / solar electricity producers has to be bought in preference to reliable sources. Nonetheless, there was more supply than demand.

As I've said, more generating capacity than demand. However, as you say, the payments to which you say are (like FITs) a political artefact of a crazy system.

Someone (you?) has pointed out that such price switching needs 'smart' devices as well as 'smart' meters. This HW system is an example of such a smart device.

Yes, that would have been me. However, the system would have to be even 'smarter' than we have been talking about if it were going to succeed in its (presumed) aim of shifting demand from high- to low-demand times of the day. Consider, for example, my E7 DHW heating, as previously illustrated. Although my immersion is switched off during E7 'peak-rate' times of day (blue parts of graph), one can get a feel for what it would look like, say, throughout the 'working day'. If, due to a period of low demand, cheap electricity became available during that period and my immersion were remotely switched on, I would actually use very little of that cheap electricity, because my 'thermal store' was already almost 'fully charged'. For the system to work as (presumably) intended, it would need to look/guess ahead and delay usage of electricity until a low-demand period arose (assuming it did!) ...

I'm not sure. Dips in supply (from solar / wind) are mostly covered by CCGT generators. However when they start up the GT part works immediately but the steam turbine takes time to get up to working temperature, 10-30 minutes from what I have read. As the dips can easily be shorter than this time the steam turbine never gets up to temperature. In that case the system is not operating as a CCGT (55-60% efficient) but as an OCGT (c. 35% efficient).

I did say "... little, if anything, more ...", but I agree that if they had to run up an additional GT 'from scratch' there would be a brief period of increased generation cost.

Also, if you look for information on electricity wholesale prices, e.g. ... http://www.wrap.org.uk/content/electricity-spot-prices ... you will see that there is quite a bit of variation, and some of that must come from varying costs of generation.

Possibly 'some of it'. However, as I said, manipulation of prices in response to changes in supply/demand are not necessarily anything to do with increased production costs. Whether one is talking about oil. gas, gold, diamonds, strawberries or sugar, if supply starts diminishing in relation to demand, the suppliers know that there are people who would be prepared to pay an increased amount in order or secure/maintain their supply, even though the cost of production/supply had not increased (i.e. paying more for 'rarity') - so they put up the price (and increase their 'per item' {but not necessarily total} profit).

Kind Regards, John

 

[JohnW2]

IIRC from what you've written you don't have a combi, so probably aren't familiar with some of their drawbacks..

You are right that I don't have one, but many/most of my family members (and many of my friends) do, so I am fairly familiar with them, at least from a user's perspective. However, ....

There are two modes they can run in, some have this as a setting (eg "eco mode")Just stay off when no demand (eco mode on). Little by way of standing loss, BUT there is a considerable delay between turning on a hot tap and getting hot water while the boiler fires up, heats up the primary loop, heats up the DHW heat exchanger, and eventually hot water comes out. This can amount to several gallons of wasted water and (I've timed it !) over a minute waiting.

That is the only mode (which I suppose one could call a 'dumb' mode) with which I am familiar. Despite what you say above, and previously, I have never experienced these long delays you mention - never more than a small number of seconds, at most, before (usually 'too'!) hot water appears at a tap when it is turned on. In fact probably no more delay than one experiences in getting hot water to a tap which is a significant distance away from the DHW storage cylinder.

Stay hot (eco mode off). In this mode, they fire up from time to time to reheat the DHW heat exchanger and primary loop within the boiler. As little is lagged, and there's a great high capacity water-air heat exchanger, standing losses are not as low as you might imagine. From the use PoV, this means much quicker hot water.

As above, I have not knowingly experienced that system, and nor have I experienced a situation in which a user was dissatisfied with the speed of appearance of hot water at a tap. Anecdotally, as above, after a significant period of non-use of any hot tops, hot water at my daughter's kitchen tap appears very much quicker from her (nearby) combi than does it in my kitchen (which has a good few metres of pipework to the DHW cylinder).

A system which 'unnecessarily' regularly heats up largely unlagged parts (seemingly for the sole purpose of producing 'even more rapid' hot water) is clearly going have an appreciable impact on overall efficiency (hence running costs). I also suspect that, even with that 'inefficient' system, it is only a major issue in summer - since when the CH is running, I would imagine that the DHW heat exchanger probably gets fairly hot, even when hot water is not being drawn.

Are people getting so 'spoilt' that they are now prepared to pay significant money to (you believe) get hot water to their taps a bit quicker than has satisfied them for many decades?

Kind Regards, John

 

[StephenOak]

Perhaps you are aware of the old "lets play a trick on the new apprentice" one of telling them to go to the stores for a bucket of electricity

I always liked the one that involved sending the new apprentice to stores for a long stand. The chap in stores would tell him to stand there and wait for it ...

[The capacity of the Barrow grid-scale battery is] something in the order of 1000th (0.1%) of UK lecky usage for just 30 minutes.

For comparison Dinorwig, pumped storage, is something like 6% for 8 hours if it was fully exhausted. That, IMO, is truly grid-scale.

If, due to a period of low demand, cheap electricity became available during that period and my immersion were remotely switched on, I would actually use very little of that cheap electricity, because my 'thermal store' was already almost 'fully charged'.

Apples to oranges comparison. You have E7 and (AFAIUI) the Mixergy (sp?) system does not need that. Also you are always (normally?) fully heating you water tank every night whereas the Mixergy 'smart' system looks at the usage and only heats enough water for what you will need and so there will be capacity to use cheaper electricity.

Not that I am advocating that system. Just that it is a different approach and any comparison must be a valid one.

I did say "... little, if anything, more ...", but I agree that if they had to run up an additional GT 'from scratch' there would be a brief period of increased generation cost.

Well to me 'little, if anything, more' means zero or essentially zero and I think I showed that it is not zero. AFAIUI they do have to start GTs from scratch and roughly halving the efficiency of a multi-MW device for 10-30 minutes is going to cost.

Possibly 'some of it'. However, as I said, manipulation of prices in response to changes in supply/demand are not necessarily anything to do with increased production costs.

You seem to be taking it for granted that all electricity generating facilities have essentially the same costs* and that the vast majority of differences in the amount charged is down to market manipulation. Do you have any any evidence to support that latter contention?

* My understanding is that (after baseload) electricity buyers have to give priority to solar / wind but then choose the cheapest sources. As demand rises, all of the cheapest category (CCGT?) is exhausted and then they choose the next cheapest category.

Part of the reason for coal plants shutting (even before their permitted hours are up) is that they have fixed costs (e.g. maintenance costs) but are being used a lot less, hence those fixed costs are spread over few hours of output sold, thus putting up the cost of those hours.