DIY Solar Photovoltaic installation - Domestic.

[dspp]

Some comments in the thread about the end of gas boilers prompted me to think about solar photovoltaic arrays. So as not to hijack that thread -

I recently did the sums for a typical 3 to 4kw domestic solar array in the UK versus what seems to be an installed cost typically around the £5000 mark for a roof mounted array, inverter and installation. I was amazed to find researching this that the exact same systwem installed locally here in Australia costs about 25 to 35 per cent of that cost. In a nutshell, the economics stack up very well here in Australia but when I retire and return home, the return is very unattractive. As far as I can see, the installation costs in the UK are what drives the big difference in price. Somewhat surprising since skilled labour here in Australia is amongst (if not the most) the highest cost in the world.

So - If I could buy and fit the hardware myself and cut out the labour, it seems the cost becomes much more attractive. Is DIY even an option for a grid connected typical house in the UK? I am not an electrician, I am an engineer and I understand things like schematics, single line diagrams etc etc.... I think it would be a doddle fitting them to a (large) shed roof or even a pergola erected in the gardrn for the purpose.

But, is it possible? Is it legal? What will my house insurance company think?

Cheers.

RVF.

Whatever you connect to the UK mains by way of permanent wiring must be signed off by a competent (part P) electrician*. And backfeeding into the mains from temporary connections is a big no no. It is a long time since being MIEE was an equivalency for what is now part P signing authority. These are legal/regulatory considerations, but in turn they have insurance ramifications.

I am not sure your sums are correct by the way.

regards, dspp

* I'm not saying that I don't occasionally do the odd bit of stuff myself, but I make darn sure I don't get caught ! And for a 4kW install I get the local part P guy to do the job, even if I do act as his/her dumb labour.

[pochisoldi]

I would say that it would be almost impossible for someone to install their own PV and connect it to the mains, without, as a minimum, having someone else certify the work.

The risks are just too high - for example, you don't want a PV system trying to re-energise the incoming mains supply when the network power fails.

The requirement for certification is widespread - the DNO will need it before they let you connect your kit to the network, your insurance company will want to see it (but only after "an event"), and you won't be able to sell the property unless you have building regs sign off.

Even if you wanted to DIY and have the kit feed a separate "off grid" installation, you will still need an installation which meets building regs Part P requirements, which in turn means conforming to the latest version of the IEE wiring regs, with the added complication of ensuring that your mains fed supply and your "isolated" PV supply don't interfere with each other (e.g. earthing systems, accidental cross-connection).

I've looked at a very small scale PV+lead acid battery installation to allow me to charge my phones and batteries for free (around 120Wh of storage), and came to the conclusion that unless someone gave me a free solar panel to go with the spare VRLA battery I already have, the payback in terms of money (and to a certain extent CO2 emissions) would be measured in years.

I think the future money for those of us with a decent sized roof facing due south, will be PV+storage+intelligence, but this won't be worthwhile until there is demand related charging for electricity (i.e. encouraging the storage/consumption of cheap electricity, and exporting power when the sun goes in and/or the wind drops and higher cost sources are turned on)

[PhaseThree]

Some comments in the thread about the end of gas boilers prompted me to think about solar photovoltaic arrays. So as not to hijack that thread -

I recently did the sums for a typical 3 to 4kw domestic solar array in the UK versus what seems to be an installed cost typically around the £5000 mark for a roof mounted array, inverter and installation. I was amazed to find researching this that the exact same systwem installed locally here in Australia costs about 25 to 35 per cent of that cost. In a nutshell, the economics stack up very well here in Australia but when I retire and return home, the return is very unattractive. As far as I can see, the installation costs in the UK are what drives the big difference in price. Somewhat surprising since skilled labour here in Australia is amongst (if not the most) the highest cost in the world.

So - If I could buy and fit the hardware myself and cut out the labour, it seems the cost becomes much more attractive. Is DIY even an option for a grid connected typical house in the UK? I am not an electrician, I am an engineer and I understand things like schematics, single line diagrams etc etc.... I think it would be a doddle fitting them to a (large) shed roof or even a pergola erected in the gardrn for the purpose.

But, is it possible? Is it legal? What will my house insurance company think?

Cheers.

RVF.

I'm intending to install my own in the near-ish future and as you say it's not difficult from the electrical point of view. The details will depend where in the UK you are living, Part-P doesn't exist in Scotland or Northern Ireland and differs between England and Wales.

The following website sells DIY solar kits and has an FAQs covering electrical instalation.
https://www.pluginsolar.co.uk/

[dspp]

Some comments in the thread about the end of gas boilers prompted me to think about solar photovoltaic arrays. So as not to hijack that thread -

I recently did the sums for a typical 3 to 4kw domestic solar array in the UK versus what seems to be an installed cost typically around the £5000 mark for a roof mounted array, inverter and installation. I was amazed to find researching this that the exact same systwem installed locally here in Australia costs about 25 to 35 per cent of that cost. In a nutshell, the economics stack up very well here in Australia but when I retire and return home, the return is very unattractive. As far as I can see, the installation costs in the UK are what drives the big difference in price. Somewhat surprising since skilled labour here in Australia is amongst (if not the most) the highest cost in the world.

So - If I could buy and fit the hardware myself and cut out the labour, it seems the cost becomes much more attractive. Is DIY even an option for a grid connected typical house in the UK? I am not an electrician, I am an engineer and I understand things like schematics, single line diagrams etc etc.... I think it would be a doddle fitting them to a (large) shed roof or even a pergola erected in the gardrn for the purpose.

But, is it possible? Is it legal? What will my house insurance company think?

Cheers.

RVF.

I'm intending to install my own in the near-ish future and as you say it's not difficult from the electrical point of view. The details will depend where in the UK you are living, Part-P doesn't exist in Scotland or Northern Ireland and differs between England and Wales.

The following website sells DIY solar kits and has an FAQs covering electrical instalation.
https://www.pluginsolar.co.uk/

It is frustrating isn't it.

There is an equivalent regulatory requirement to part P in all the UK, though I agree details do differ.

That website etc is very much skating on regulatory thin ice, and they are exceedingly careful with their phrasing, and I'd be very cautious.

The pricing of the stuff in the kit on that site (£4.2k for 4kW) is scarcely below getting a proper MCS installer.

regards, dspp

[todthedog]

Easy to self install have diy'd solar pv, solar thermal , and a wind turbine. Big Boys mecanno. That was in France buying the components on the open market and then getting the system signed off. That was tricky the French love their forms.
The UK renewable energy industry has been dealt a series of hammer blows by successive administrations, it is probably just as easy and cheap to get someone to do the work for you. If you have sufficient space consider a ground mount system, scaffold poles are brilliant for this. PV panels are more efficient cool, easy with a ground mount.

All inverters sold legally in the EU have 'islanding' installed, if the mains go down the inverter. if grid connected immediately stops to make it possible to make repairs to the grid. This of course may change in non EU free Britain.

[pochisoldi]

Now, this might seem slightly barmy, I just thought about it. I can buy the complete PV kit down here, claim the tax back when I leave. Returning expat to the UK can bring personal goods into the UK free of tax (subject to certain rules). Given the huge price differential between here and the UK for the exact same thing, I reckon I could buy all the kit here and ship it to the UK and stll save more than half the cost of buying it in the UK. How mad is that?

You might find that you have to have owned the stuff for at least 6 months before importing it as personal goods:

https://www.gov.uk/government/publicati ... ide-the-eu

The relief does not apply to:
...
goods you have not possessed or used in the last 6 months