The largest system I've seen!

Screwdriva

Thought I'd share what 52 bifacial rooftop panels (paired to 2 X Tesla PW3 battery inverters) looks like! DNO export permission for 22 kWh approved, also the highest I've been involved with! Expected annual generation is 20+ mWh!!  

QrizB

That's quite something!

Looks like shading might be a concern? Possibly they've got so many watts that they can afford to lose a few

MeteredOut

Care to share the cost? With 2 x PW3 (and looking at the house), I doubt the cost was too much of a concern to the owner

PS. I think they could have squeezed one more panel on there

Screwdriva

QrizB said:

That's quite something!

Looks like shading might be a concern? Possibly they've got so many watts that they can afford to lose a few

Indeed! I'm really happy with the overall result! 

Their monthly electricity bill is £3K so I suspect they're keen for every Watt. There is late afternoon shading (which is when this was taken) and shading on the right from a palm tree they plan to relocate. 

Screwdriva

MeteredOut said:

Care to share the cost? With 3 x PW (and looking at the house), I doubt the cost was too much of a concern to the owner

PS. I think they could have squeezed one more panel on there

It was under £28K for everything, with an expected payback period of 5 years (less if he electrifies his heating and gets an EV, which are his next projects). Any extra panels would have partially covered the ceiling windows by 7 inches - I had the discussion with the owner (who is a close friend) and we decided it would take away from the aesthetics of the structure.. 

MeteredOut

Screwdriva said:

MeteredOut said:

Care to share the cost? With 3 x PW (and looking at the house), I doubt the cost was too much of a concern to the owner

PS. I think they could have squeezed one more panel on there

It was under £28K for everything, with an expected payback period of 5 years (less if he electrifies his heating and gets an EV, which are his next projects). Any extra panels would have partially covered the ceiling windows by 7 inches - I had the discussion with the owner (who is a close friend) and we decided it would take away from the aesthetics of the structure.. 

Yeah, I was thinking about that space on the middle right, to the left of the roof windows, but it would look a bit weird with one panel 90 degrees to the others. It's not as if one more would that that much difference!

Good price for all that work.

michaels

How on earth did they get DNO approval, my parents have a 4kwp system and were refused permission to ad any more.

Screwdriva

michaels said:

How on earth did they get DNO approval, my parents have a 4kwp system and were refused permission to ad any more.

I'm learning that it's an art as much as it is a science. In this instance, the extremely high import (it's a 3 phase household) per phase was highlighted to the DNO. Approval was received the same month. 

Heedtheadvice

Screwdriva said:

michaels said:

How on earth did they get DNO approval, my parents have a 4kwp system and were refused permission to ad any more.

I'm learning that it's an art as much as it is a science. In this instance, the extremely high import (it's a 3 phase household) per phase was highlighted to the DNO. Approval was received the same month. 

That would certainly have been a help as one of the necessary aims for a supply is to keep the three phases' currents in balance thus reducing the 'neutral' current. This keeps the cost of the supply transformer down and maximises it's efficiency as well as reducing the size of the neutral cable.

A large power draw or generation on a single phase of the three does the opposite and makes balancing the power on each phase more difficult.

Screwdriva

Twin PW3s commissioned. 

94JDH

Looks great, currently running 49 panels (19.8 kW) & 38 Kwh batteries myself. Not all in ideal positions, but does cover all my costs (over the year) with the correct tariff in a 1930's detached house with ASHP, EV & hot tub. Single phase only though.