Beelbeebub

German talking about plug in solar (4m installs) for the UK. One interesting titbit... The plug in soecs/limits are designed for the likely worst case German home electrical system - he mentions "pre war" and "East German with aluminum wires and worn contacts". So the Germans have designed the systems to be safe for those scenarios. Are uk electricans, who argue that plug in solar is dangerous, arguing that uk homes are likely to have worse wiring than pre war and east German wiring? Plug in solar is going to be a useful thing for tenants. Uk rental properties choukd all have been inspected at least twice now so any really shocking (ha) working should be rooted out of that market segment.

Yes, although the problem might be that to achive 207 during a winters night with all the electric heaters on at the hypothetical remote farm, the output at the substation might need to be cranked up 249v Obviously the farmer's near neighbour's solar isn't going to help then. It would help the farmer if he had low voltage when the sun was shining (say a big air con load) but the transformers are not automatic. They are mainly set and forget. An engineer needs to visit and physically move some contacts to change the voltage If the houses near the substation are all cranking out loads of power on a sunny day that is what will push the voltage over. All that said, some batteries at the farm would help as they would be able to reduce the load on the wires, thus reducing the current and voltage drop. So whilst a 90a draw from the grid onky might drag the voltage down to 207, the 45a from grid and 45a from batteries wouldn't, so the transformer voltage could be set lower. As an aside, this "solar reduces load on wires" principle is why I think some of the panic over plug in solar is overblown. I did some basic calculations and I think, for any correctly functioning socket circuit the 4a/800w plug in solar can produce isn't able to overload the cables and might even allow higher loads than the circuit breaker is set to without overloading the cables. Of course if there is a faulty or out of spec socket circuit, plug in solar might cause a problem, but at that point normal use would also cause the problem.

The pressure was probably more indirect eg. the CEO of the building company having a word with someone in the council over a few drinks in the golf club bar as they discuss donations and upcoming non-executive directorships. 😁

Yes, if the can widen the window by lowering the bottom it will help. Current UK is 240 +10/-6 ie 216 to 253 Europe is 230 +/-10 which is 207 to 253 I think our asymetric limit was fudge when we standardised with Europe and everyone actually stayed the same. Bu as you say - all modern equipment will function absolutely fine at lower voltage. There might be an issue with higher currents for constant power devices at the lower voltage. I noticed my inverter (solax) has a power based export limit. Eg 3.6kw whilst my DNO specified a current limit (16a). The lower minimum voltage could mean those of us with power based limits will have to assume 207v ie 3.3kw rather than being able to set 3.6 or even 3.9kw.

Isn't the issue that a local grid may be very spread out so the voltage at the transformer needs to be (say) 249v to ensure thr person at the farm miles away gets at least 220 (or whatever the lower limit is) in the worst. Which was fine when everybody consumed. The local voltage could be set high at the transformer and would never go higher as everyone consumed. But if the people next to the transformer are exporting, they need to push the voltage above 249 to export, and if there are too many people too close the voltage could go above 253v. If the grid lower the transformer voltage to 245 to give headroom, they endup only supply 216 to the poor sod at the end of the line. The solution is to reduce the voltage drop between transformer and the end of local network ie new cables.

That makes sense😁

AAV could have failed - in which case the smell should be worse there. The other thing we had with a waste disposal unit was the flow rate was too high for the (old and clogged) pipework so we ended up displacing air back up via the overflow, which was pretty stinky.

The bigger issue is that private building control, at least in the context of commercial builders, have the wrong incentive structure. A guy who will sign off anything and never insist on rework will get hired repeatedly. The inspector who insists all the houses on a development need to be reworked because the brickies didn't bother with wall ties isn't going to get the next contract.

What is the difference between "new electricity demand" and "demand growth"? The thread title seems accurate and the same as your description. "Renewables met demand growth...while fossil generation stalls, i.e doesn't grow. "

You are correct but if you read the post carefully you'll see I said half hour block (the standard time slice for the grid). If your export limit is 3.6kwh and you export any more than 1.8kwh (eg 2.5kwh) in a half hour block you have breached your export limit. The half hour time slice means it is much harder to hide any over export with any inevitable lower export periods eg clouds going over sun for 10 minutes and the system is already working at that resolution. If you do this for every half hour slice you can discourage over exporting because there will be no financial benefit and you might get a visit from the DNO.

Isn't the key problem for any "combi" heat pump going to be defrost and oversizing? For a combi type water flow you need 25kw or so output. With a gas boiler, that's trivial and can be modulated down to 3 or 4kw for heating. Getting a continuous 25kw from a HP means you need more than 25kw to allow for defrost. Such a HP would be large, expensive and struggle to modulated down. Anyrhing else is just a variant of a thermal store or unvented cylinder.

Surely, if DNOs wanted to police the export limits to check nobody is sneakily upping their export limit, they need to check the meter measured export. It's stored in half hourly blocks long term and availible in minute to minute blocks as well If some is exporting 2.5kwh in a half hour block they are certainly breaching their 3.6kw export limit. One strategy would be to cap export payments at whatever your dno limit is. Therefore removing any incentive to over export.

The "render onto foam insulation that is screwed to the wall" method has some risks. In theory a well done ewi solution should protect the building from thr elements and preserve the wall by keeping it warmer and drier. The aesthetic will almost certainly change if you start with brick or stone. There ain't really a way to mimic that - and I'm not sure we should try. Lean into the fact our buikdings are changing to adapt to new circumstances. It has always been so. Structures are extended, modified, uses change, windows are added and subtracted, uses change again etc. Many of our houses were never built with electrical wiring or central heating. A good few didn't have plumbing and some didn't even have indoor toilets. These new technologies were added as circumstance changed. The addition of ewi is just another chapter.

Interesting. This is the sort of thing that should happen. (the grant not the historical standing charges being higher)

Exactly, which makes a mockery of the whole idea of g100 certification. Maybe someone could bring out some sort of 2way breaker - 80/100a incoming (as per normal) but 16a outgoing (or whatever the dno says the limit is) that would provide an extra layer of protection.