Has plug and play solar now been passed, I see adverts?

[SimonH2]

In the absence of any over-riding 'control systems', I find it very hard to understand why the voltage produced by a generator would increase as the result of an increasing load.

I think Ericmark has answered this, but it comes down to the power station being on the end of a line with volt drops. They will have been asked to push a given amount of power into the grid, and for this to happen, their output will need to be above the desired voltage at "some point" in the network by the volt drop in the cables.
But taken by itself, the voltage at any point doesn't tell you much about the power being shovelled around the grid - other than a knowledge of how the voltage at a generator varies with it's power output. Taking Ericmark's example, the power station could be delivering 100% output and see its voltage rise. However, a very similar voltage would be seen whether it were the sole generator on a lightly loaded grid, or just one of many on a heavily loaded grid.

In terms of frequency, that's true on small scale such as you describe, but if the total load (of the entire grid) starts approaching 'maxing out' of the generating capacity, the frequency will fall.

You are correct, if demand exceeds current supply capacity then the frequency will fall as rotating machines slow down. But, that still tells you nothing about how much demand is actually there - you could overload a grid with 10GW of supply (sunny, breezy day, in summer), or with 60GW of supply (dark, still, cold evening in winter) if demand exceeds supply. So frequency only tells you anything about supply/demand if you actually know either the total load or the total supply - otherwise it only tells you about any imbalance.

One to me error in our homes wiring is to power the central heating with a FCU, if powered from a plug and socket, then easy enough to unplug from the grid supply and plug into a battery/inverter or generator. Using a FCU seems to me a flawed approch

Agreed. But then you have to contend with the heating "engineers" who still believe that an FCU is the only way to legally connect a boiler.

So to encourage people to have solar with battery back up does make a lot of sense, but the plug and play is lacking the battery back-up.

I bet very few with battery back up are actually connected to allow offline use. For example, on the Solax my brother has, the EPS is a separate set of terminals - and no-one thought to actually run any cables to where they could be useful when completely renovating the house. If it becomes a requirement to fit solar in new builds, you can guarantee that most developers will fit the cheapest option that complies - and won't go to the expense of making it support offline use.

 

[ericmark]

Agreed. But then you have to contend with the heating "engineers" who still believe that an FCU is the only way to legally connect a boiler.

I would question if they are an engineer i.e. over level 3 trained, if they believe that.

the EPS is a separate set of terminals

As is mine, and it was a hard thing to decide how much to put on the EPS, the more on the EPS the less time it will last for. I have an old power pack, and that can run standard lamps etc. And a lead to allow me to use batteries to power any sig lighter power device. The biggest problem is my wife tidies up, and they vanish, same with LED torches, cleaned up somewhere, where did you put them, gets answer in a carrier bag, or the like, so all my efforts to be prepared goes out of the window, only installed stuff works, as she can't tidy it up and hide it.

 

[JohnW2]

To feed power into the grid, the power station needs to raise its voltage, so users near the power station will see voltage raise, those mid-way to high load will see voltage remain static, and those in the high load area will see the voltage drop.

That's what I said- but, as I also said, it's due to (human or automated) 'intervention' is order to maintain the 'lowest permitted voltage' supply to the most distant consumers. In the absence of that intervention, a very large load on the system would result in generator output voltage and supply voltage (to everyone) falling, not rising.

 

[JohnW2]

I think Ericmark has answered this ...

He has, and I now understand what he's been getting at, which is exactly the same as I have been saying - that (human or automated) 'intervention' to maintain an adequate supply voltage for the most distant consumer will mean that the generated/transformed voltage, and the voltage supplied to some consumers will rise with very high loads. However, in the absence of such intervention, all voltages would eventually fall when load became very large.

You are correct, if demand exceeds current supply capacity then the frequency will fall as rotating machines slow down. ...

Exactly ...

But, that still tells you nothing about how much demand is actually there ...

I don't think that I (or anyone) has suggested that it does.

 

[ebee]

The biggest problem is my wife tidies up, and they vanish, same with LED torches, cleaned up somewhere, where did you put them, gets answer in a carrier bag, or the like, so all my efforts to be prepared goes out of the window, only installed stuff works, as she can't tidy it up and hide it.

I know that scenario very well Eric.
Tidy up is obsesive in comparison for ease of use.
Everything is moved from its handy place and moved to an obscure place.
Even things that have been in certain places for years and we all know where they "always are" get moved to another place and when I get told "well it was only over there, not far away!" (with all the places it might be - kitchen cupboards etc etc) I use my little phrase "Well it may as well be on the moon!" and a related phrase "Which part of the moon have you hidden XXX on?"

Good job I`m not a conspiracy theorist!