Solar Panels . . .

[Theo]

That's the DNO's business, which is not the problem of Octopus. Octopus want to know if you aren't doing anything fishy like taking power from your neighbour and saying it's 'generation', arbitraging at times when their export tariffs are paying more than the fixed-rate import tariff of Bob next door.

(although Octopus will probably want to check that the DNO paperwork was submitted, for <16A per phase you just fill in a form and send it in; the DNO doesn't have a veto for smaller installations)

I would be interested to know of anyone who failed the 'inspection' and the reasons why.

Theo

[alan_m]

The DNO may not have a veto but will still require the installation to be an acceptable standard.

For instance tThe DNO would like to know that you cannot feed 230V back into the networks if the power goes off, thus protecting workers trying to repair the supply.

[Andy Burns]

And is that likely to be more than filling in the DNO's G98 form with the premise details and ENA approval reference for the kit?

[tony sayer]

[nothanks]

PV systems?

[Andy Burns]

double insulated to 1.8kV DC, UV resistant, copes with wide range of ambient temperatures, LSZH ... that sort of thing, no doubt there's a spec somewhere it has to meet?

[nothanks]

Thanks (yes, I was being lazy). I'd expected the UV, LSZH and temp considerations but (showing my ignorance about PV) why 1.8kV?

[Andy Burns]

BS EN 50618 and H1Z2Z2-K

Assuming it's not microinverters, the panels are wired in series so you do get high voltages (maybe 600-700V per string) so a 2x to 3x margin of safety ...

[maus]

My opinion on solar panels. One can get money to install solar panels and get power when the Sun shines, or get the money, put it in the fireplace, set it on fire, and get heat for a while (May be difficult with bitcoins)

[The Natural Philosopher]

LOL!

Yes. In the end unless you do a very precise cost benefit analysis you really don't know, and I have seen too many people believing what they wanted to believe instead of calculating the cost:benefit.

The reality is that without government mandated subsidies there is no overall benefit.

It's the same for heatpumps and BEVs. The people who have them swear blind they work, the people who have done the sums don't buy them.

The best investment I have made is the £200 or so to build a very precisely programmable central heating controller. I believe my oil consumption has improved by maybe 30%.

That is a serious amount of money.

[Tim Lamb]

Er. 60 years ago:-) I was instructed that while a safety margin of 3 would do for mechanical structures, electrical safety required a factor of 5!

[SteveW]

Surely, for cabling, the safety margin is built in - with 250V certified cable being suitable for mains, etc. - and is actually safe at much higher voltages?

[alan_m]

But not all mains cable is UV safe.

[tony sayer]

ISTR That Theo on this group did a lot of calcs and though they did or could pay back

I did a rough one a while ago have a large easily accessible flat roof and a south facing wall i can hang some on. No scaffolding required and the cost of the panels from a local supplier was around 130 quid i see they are cheaper now, Electric is around 33 p a unit it didn't seem that long before it would be paid for. Its not going to happen before long and I'll go through it again..

And I'm sure they'll outlast me!!!

[RJH]

It's quite straightforward to calculate - I had a survey done recently. On an £8.5k SE 8 panel 6 kWh install, 13 year payback.

Some interesting details in the calculation - generation goes down by about

10% over 25 years, a £1250 every 5 years sinking fund labelled replacement built in (battery?), and export income decreases over time, from about 15% of the overall benefit to 3%.

[Theo]

Since I did that the cost of electricity has come down, so the payback gets longer. OTOH so has the cost of the panels. Redoing the costs today will be different from my 2022 calc. Obviously your site will be different so you'd need to do the solar calcs for that as well.

For a DIY install you don't get an export tariff, so you'd have to consume the energy locally. So to make it work either your consumption is aligned with the times of generation (perhaps EV charging) or you have a battery to time-shift consumption.

(Octopus may allow export on a non-MCS install with a £250 inspection - I'd get an electrician to do the connect up and commissioning - but doing that means extra costs. You'd have to calculate whether that's worth it)

Theo

[ajh]

Irish maus from wayback uk bus ag?