Beelbeebub

BP editing the north sea. https://www.bbc.co.uk/news/articles/c62q7w003lro "As we focus our portfolio and direct capital to our highest-value opportunities, we believe our North Sea business will be better positioned as part of another company" Implying that the North Sea isn't a high value opportunity. Another data point I found. In round numbers. In 2025 the UK produced 330Twh of gas and net imported 330Twh (460 imp 139 exp) for a total of 660Twh used. Of which 190Twh went to electricity production to produce 90Twh of electricity A further 250Twh went to domestic (mainly heating) Leaving 220Twh for other stuff. Renewables generated just over 100Thw. If we replace the majority of domestic heating with heat pumps we would need another 100Twh (assuming scop of 2.5) If we add another 100Twh we would be able to dissolace gas from generation* Which would leave a gas demand of around 220Twh which is around about our current production. So tripling our current production is needed - which happens to be the target. *We would still need gas plants and storage to provide backup and peaker demand, at least until we get enough storage but the overall gas demand would be much lower therefore freeing up gas for things that we cannot easily replace either with.

I'm fairly sure all "proper" inverters now have this built in. As for the micro inverters that are suitable for plug in solar - I'm not sure, obviously the "approved" ones will along with the shutdown hardware etc. I'm sure it's possible to buy some cheap ones without the necessary hardware online. But I think the main point is that even in the worst case the risk is just blowing your old RCD up with your unapproved inverter. So you end up getting a new bi directional RCD and hopefully a proper inverter. I don't think there is any additional risk to things catching fire or people getting shocked beyond the normal risk whenever you plug something in. There are plenty of dodgy gizmos you can buy online that have a far higher likelihood of shock or fire than your old RCD crapping out

IIRC, the issue with unidirectional RCD/rcbo only occured if the inverter continued to feed power when the grid goes down -which shouldn't happen (as has been pointed out) And then the problem resulting from that situation is that the RCD/rcbo is damaged - which would result in a dead circuit and the home owner getting it replaced with a bidirectional one I think the bigger issue is the electricians industry bodies not wanting something where electricians aren't needed. I am fairly sure they would mandate only qualified electricians are legally allowed to plug or unplug devices if they could.

I was thinking of the higher rates! They were 15p, now 12p And I suspect they will keep falling as solar generation gets more and more common. https://www.theguardian.com/environment/2026/aug/02/solar-powers-record-share-britain-electricity-july

Yes, no plans to sell. I've looked at the multi tenant systems (solshare or something). They are pretty pricey (5-10k) and have 15 outputs (5 x 3phases) so make the most sense in blocks of flats. That is the most hard nosed approach but the benefit to the tenants is much more limited - especially with lower export rates.

If I did an AC transmission system the temptation would be to make it a non battery system and leave fitting of batteries to soak up the excess something for the tenants to do if they wish. This might be easier with plug in battery systems.

There are 4 houses in a loose crescent around a "green". A field backs on to the "green" to the north with a high hedge The panels are being fitted to comply with the EPC regulations and get each property to. "C" grade 1 house is a good candidate for normal E/W roof solar being a bungalow with a low pitched concrete roof. The other 3 have problematic roofs. Either not good aspect (shaded) or not good enough condition to allow solar to be fitted with out a new roof first or both But a ground mounted array could be fitted in the "north" field out of sight (and far enough back so it's not shaded by the hedge. I figure it's easier and cheaper to install and maintain one array in a field than 3 arrays on 3 roofs. And then for the bungalow I have to decide if it's cheaper/easier to put panels on the roof Vs chuck some more up in the field array and run a cable to it (that would be the 100m one. The others are closer to 50m) Strictly speaking the batteries are not needed as the EPC system currently only accounts for the panels and inverter - you get no points for batteries. But it gives so much extra benefit to the tenants it's hard not to justify it beyond the purely mercenary view.

Good point The array will be fairly large (maybe 8+ panels for each house) so the voltage will probably be higher than mains so the current lower. Plus we have had high voltage issues in the past.

In favour hybrid systems so the battery generally needs to be next to the inverter. If I use the AC method then there is one AC line (a line, neutral and earth) going to the remote inverter connecting to the meter tails between the meter and the consumer unit and I need a switchover box at the house to isolate from the mains in a power cut so I don't energise the mains. I could arrange for power cut cover but there would need to be a Comms line as well which cuts onto the cost savings.

Not a bad idea, it would definitely cut cable costs but I think i'd I be giving up the power cut backup function? And is there a problem with exporting the earth? The panels will all be earthed together by virtue of being fixed to a metal frame stuck to the ground. But the houses they supply are 50 to 100m away. wouldn't the same issue with car chargers and remote earth/faults raise it's head?

I don't have a fence only a hedge, and at one point I have to pass a gate and another a drive way. In the field I could see effectively building a fence to carry the cable - i'll probably do that. at least the buried sections will then not be in a field. the biggest bugger is there are a ton of other services around, gas, mains, water and sewage plus some telephone. Potentially I could go overhead the whole way, it's just passing over the drive way and gate are a bit untidy.

Good point. Though I can guarantee the field isn't going to get ploughed anytime due to the slope and it also being an orchard. It's a short run from the array site to the edge of the field so I could mount it above ground on some timber rails. If I run it behind the hedge in a similar manner I could minimise the distance underground as @JohnMo suggests. Looking at the site I realise there already is a telephone line overhead along the fence. I wonder if I could run the cables overhead for a good chunk.

For at least some of the run they will go across an agricultural field (sheep) that is occasionally flail mown and then also across a lawn which is regularly mown and trafficked. Also across a tarmac drive. It's (hopefully) a single ground mounted array that serves several houses. The other alternative is overhead poles but that has issues too.

Does anyone have a reference for the depth that DC cable needs to be buried - I assume the same as armoured AC (0.5m in general) but wanted to double check. I was going to use the specific armoured stuff

The Spain/Portugal blackout last year comes up as an example of why renewables are dangerous.quite often. Nice explainer video of what happened. TLDR: 1. The Spanish grid regulations did not use the capability of renewables to stabilise the grid. This made them reliant on fossil fuel plants for grid control 2. Earlier oscillations in the grid caused the grid operator to demand higher voltages to dampen them (as is normal practice) 3. One of the 10 fossil fuel plants had a fire and had to shut down leaving even less grid control. 4. Some of those fossil fuel plants didn't it comply with the procedures so the voltage rose more than desired but still below the threshold 5. Some PV plants had been misconfigured to shutdown at a lower voltage than they should have and tripped out. So the main takeaway was the Spanish grid was not well managed. It also makes the point that the model the Spanish used (relying on fossil fuel plants for stability alone) is not followed in the UK where the renewables are configured to contribute to grid stability