New Supply and PV quandry

[Johnnyt]

Hello all,

 

Yet to start on my build which is likely in the next couple of months.

I have been discussing the new supply and PV with my DNO Scottish power and there are 2 routes for the new supply one down the pavement adjacent to our plot and the other buries across farmland we own and rent out, at a cost of 17K and 10K respectively.

 

See below from Scottish Power

 

"Route 1: £17,000 + VAT - this involves excavating and laying a 185mm waveform cable in pavement and verge for a distance of 60m, including an estimate for traffic management costs.  It would enable an Agreed Export Capacity of 9kW 1-phase, which may be export-limited if desired from a Power Station Capacity of 15kW.  This would provide a 100A 1-phase supply to the first plot and another as the temporary site supply.  The service alteration to convert this second supply into the permanent supply to the other domestic plot is not included.

Route 2: £10,000 + VAT - this involves laying a 185mm waveform cable in a customer trench in the field at the back of the existing properties on New Road for a distance of 135m.  It would enable an Agreed Export Capacity of 12kW 1-phase, which may be export-limited if desired from a Power Station Capacity of 17kW.  This would provide a 100A 1-phase supply to the first plot and another as the temporary site supply.  The service alteration to convert this second supply into the permanent supply to the other domestic plot is not included.

Please can you confirm which option you wish to pursue?

If you do not yet know the exact generation arrangement you will be installing, this can be applied for at a later date.  This will incur a network design fee of £300 + VAT whether you include the generation now or later, so I would imagine a separate application would be preferable."

 

I can comfortably get 18 in roof panels of the southern (SSE) elevation 5.4Kw of the new build and I have decided to go for a steel portal garage outbuilding that will accomodate a futher 12, 2.4Kw on the garage roof (WSW).

 

The question is do I max out to future proof now, as we have mains gas to heat UFH but I intend having the pipes laid at 150mm centers to allow for future ASHP heat source. The ground floor area is 170 sqm. Our current usage at our present home is circa 3500kwh a year with a PV generation off a 2.75Kw sytem of 2300Kwh pa but on a house a third of the size.

 

The other plot referred to above belongs to my builder

 

Thanks J

 

 

 

[ProDave]

No brainer for me, the £10K route with 12KW export capacity, and apply for the export now to save the later fee.

 

The £7K saved Vs the other route should par for the PV

[scottishjohn]

as more people try to increase the export potential there will be a maximum your line can take --so if you go for 4kw now ,there maybe no spare capacity later 

so do it now .

It is  these limits that are stopping a lot of commercial solar farms 

So it is reasonable to assume there will be a maximum for private generation on lines as well-- reserve it now

when limit of excsisting line is reached --eg transformer at sub station ,then if you want to breach that limit  you have to pay for the upgrade

It is these costs that stop  new commercial farms

 

Edited January 4, 2020 by scottishjohn

[Johnnyt]

Thanks for your replies.

 

I think I had decided to use the route across the farm land which allows the greater generating capacity.

What puzzled me whether to go for the full 12Kw fitted or a lesser amount. Are you saying I can apply for the12 Kw and "bank it" so to speak, fit a lower amount and then  build up to it  at a later date.

I would like the extra capcity for the possible future ASHP and of course more generation at time of low irradiance in the winter etc .

 

 

[ProDave]

As far as I know the DNO never come to check what you have installed, so apply for and get permission for the full eventual system, then install "phase 1" and they will never know that it is taking you a long time to get around to phase 2.

[scottishjohn]

14 hours ago, Johnnyt said:

Are you saying I can apply for the12 Kw and "bank it" so to speak, fit a lower amount and then  build up to it  at a later date.

I am saying that is what happens with commercial solar farms --they buy an option basically --which then means if that is all the capacity the local sub station can handle ,then noone  else can use it

If it were me  ,yes i would bank it --it maybe not a problem now ,but if every body starts doing it --then I believe the DNO will start rationing how generation they allow for private dwellings as well.

I have no hard facts to back this up only  what i have been told regarding commercial solar farms  

lots of good sites --but it is spare capacity in the grid which is limiting more being built incertain parts of the country 

[Johnnyt]

That's great advice thanks.

It's quite a generous offer from the DNO, I imagine as the primary is nearby with 33kv and 11kv.

The transformer we would connect to with 135m of underground cable only serves 6 properties, at least we don't have to pay for any infrastructure upgrade.

 

Good news all round

[joth]

Blimey, I wish ukpower networks were so generous. We made a G99 application it took about 3 months for them to process, was approved for 7.6kW (and not one watt more), and had a validity of 90 days for the complete system to be installed and fully commissioned -- and whatever is commissioned at that point, they say, is all we'll ever be allowed.

That 90 days expired before we could move on it. The panels take 90 days to manufacture, let alone deliver, install and commission, so I have no idea what the correct order is for making a renewed application vs placing the order.

 

[ProDave]

9 minutes ago, joth said:

Blimey, I wish ukpower networks were so generous. We made a G99 application it took about 3 months for them to process, was approved for 7.6kW (and not one watt more), and had a validity of 90 days for the complete system to be installed and fully commissioned -- and whatever is commissioned at that point, they say, is all we'll ever be allowed.

That 90 days expired before we could move on it. The panels take 90 days to manufacture, let alone deliver, install and commission, so I have no idea what the correct order is for making a renewed application vs placing the order.

 

But do they want to come and check the install?

 

If not, just tell them it has been done.