UK achieves solar power record

[Stones]

http://www.bbc.co.uk/news/business-40058074

 

When I heard this on the radio, the thing that jumped out was the comment that the National Grid was paying companies to use electricity at times of peak (wind and solar) generation so it could manage what was being generated.  Wouldn't it be nice if domestic consumers were offered the same...

[Ferdinand]

15 hours ago, Stones said:

http://www.bbc.co.uk/news/business-40058074

 

When I heard this on the radio, the thing that jumped out was the comment that the National Grid was paying companies to use electricity at times of peak (wind and solar) generation so it could manage what was being generated.  Wouldn't it be nice if domestic consumers were offered the same...

 

That is presumably big installations that normally run on cheap overnight electricity.

 

Charging milk floats? 

 

Ferdinand

Edited May 27, 2017 by Ferdinand

[MikeSharp01]

Are electric milk floats still a thing? 

[Jeremy Harris]

The negative pricing was something that was predicted as a possibility when the open wholesale generation market was created.  As I understand it, the price paid to generators varies a great deal, hour by hour, as demand changes.  It's a classic supply and demand model, but taken to a pretty fine degree, so generators that can't reduce capacity quickly (as in a few tens of minutes) get penalised because the wholesale price just plummets. 

 

I'm not convinced that such a volatile market is a particularly good way to ensure that there is a robust supply, but it may be OK.  There's enough money to be made during high demand, low generation capacity, periods that generation companies can afford to have fields full of standby diesel generators sat idle, to be turned on only when the price makes it profitable to run them.

[SteamyTea]

I just heard the Beeb report.  The thing that struck me about it was that they mentioned that around Noon it was producing more than our 8 nuclear installations.

Hopefully that should being the message home.

 

It is much easier to get few large consumers to use power than 30 million domestic consumers.

I don't have a problem with that.

 

A quick chart I have just knocked up.

 

 

[Jeremy Harris]

Interesting to see that coal is generating practically nothing and that CCGT is doing the load balancing, ramping up and down pretty rapidly to meet the changing demand as solar and wind kicks in.  Looks like three near-perfect solar days, too.

[PeterW]

5 minutes ago, JSHarris said:

I'm not convinced that such a volatile market is a particularly good way to ensure that there is a robust supply, but it may be OK.  There's enough money to be made during high demand, low generation capacity, periods that generation companies can afford to have fields full of standby diesel generators sat idle, to be turned on only when the price makes it profitable to run them.

 

So to compensate for the lull in wind they are installing a number of these near me - apparently they are heavily subsidized just to sit idle ..! There are 8 of them in the edge of an industrial park just waiting for the wind to drop ...

[jack]

10 hours ago, JSHarris said:

Interesting to see that coal is generating practically nothing 

 

I knew we'd moved away from coal but that's a startling graph.

[Triassic]

I worked for a time in a mixed fuel power station, coal or oil depending on price. We also ran a 28 Megawatt gas turbine which we could bring on line, from cold, in ten minutes. It was a great profit centre, especially around 8pm when everyone made a brew, when the spot price spiked.

[SteamyTea]

What I find interesting about the graph is that frequency does not correlate well with demand very well on the 25th.  I am not sure if that was just a 'bad day' for the grid, or there is something much more fundamental going on.

One of the problems is that the power auction for each half hour block to help balance the grid closes about an hour and a half before it is delivered.  Then something unexpected can happen.

[Jeremy Harris]

I have a feeling that distributed generation can cause the grid frequency to do some odd things, as most grid tie inverters use frequency as an indicator of load, I believe.  I would hazard a guess that having significant power inputs, from generators that have virtually no "flywheel effect" might cause the grid frequency to do some unusual things, as might the impact of HVDC distribution, with local AC conversion.  Not sure about any of this, but I recall reading an article some time ago that suggested that grid frequency stability might be impacted by lots of small scale generators.

[Stones]

5 hours ago, JSHarris said:

I recall reading an article some time ago that suggested that grid frequency stability might be impacted by lots of small scale generators.

 

I recall something similar.  I was of the understanding that we needed constant baseload to iron out the peaks and troughs associated with renewable generation, which by its very nature is variable.  I seem to recall significant concern about this when Longannet Coal Power Station was closed and the impact it would have on the Scottish grid stability.

 

Is the difference in frequency shown in the graph +/- 0.05 significant in how the grid operates and the effect it has on us as end user?

[Temp]

On ‎5‎/‎27‎/‎2017 at 09:04, jack said:

 

I knew we'd moved away from coal but that's a startling graph.

 

I read somewhere that we still subsidise coal to the tune of £300M a year.