The largest system I've seen!

70sbudgie

How do the Powerwalls generally compare in physical size to other batteries? Every time I see a powerwall installation, I think "that is so small and tidy". The one above even more so. I understand the numbers, but still can't wrap my head around the energy densities. 

Screwdriva

Much more "petite" than a GivEnergy All-in-one, which to me is the only real comparable battery. 

Hexane

Screwdriva said:

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!!  

How long did it take to generate the 22kWh that had been approved, and what do the owners plan to use the system for after that limit was reached?

I think even our tiny system could generate 22kWh in just a single day (if the sun shines enough)

Solarchaser

That is an impressive amount of panels.

I do wonder what you can spend £3k a month on for electricity alone, when it's not even doing heating?

Thats 10,000kwh at 30p/kwh
So 333kwh / day or a constant draw of nearly 14kw.
It's a large house, for sure, but not that large.
Also means both powerwalls will be flat inside 2 hours of the sun going down. 

Powerwalls are about average size for the storage they hold.
The fogstar batteries at 15kwh are not as wide, but protrude more, though they don't also hold the inverter and are £6k cheaper

Screwdriva

Hexane said:

How long did it take to generate the 22kWh that had been approved, and what do the owners plan to use the system for after that limit was reached?

I think even our tiny system could generate 22kWh in just a single day (if the sun shines enough)

I don't believe the system has hit 22kWh peak generation yet (which is what DNO's approve) but daily generation is currently around 70-90kWh. That said, the bifacial panels sit at ~15 degree slope (similar to a flat roof installation) and so I expect outperformance as the sun rises higher. I'm expecting 120kWh or more generated per day from May through August. 

Solarchaser said:

It's a large house, for sure, but not that large.

Uhhh...that's not the house. That's just the pool house complete with Jacuzzi, Sauna, heated pool and a few more amenities. The house sits alongside and is around 5X the size of the structure pictured. 

Solarchaser said:

I do wonder what you can spend £3k a month on for electricity alone, when it's not even doing heating?

Thats 10,000kwh at 30p/kwh
So 333kwh / day or a constant draw of nearly 14kw.

Their consumption is not linear but the PW3's are flat by around 9pm. He is evaluating the addition of a 3rd PW3 to achieve full 3 phase backup and achieve grid independence till the Intelligent Go window. 

Their heating bills are another £1500 per month (4 boilers!). I am trying to highlight the merits of a cascaded ground source heat pump solution (they have 4 acres of sun soaked land for slinkies)) but I am doing all of this pro bono and have only so many hours to dedicate to helping others in a day...much to the ire of Mrs. Screwdriva!

Solarchaser said:

The fogstar batteries at 15kwh are not as wide, but protrude more, though they don't also hold the inverter and are £6k cheaper

Fogstar/Seplos was not considered for this project. 

Solarchaser

Haha, of course fogstar wasn't considered, you love a powerwall.

If that's not the house, I'm surprised you haven't got more on the house.

If they are using 14kw average, then you could add another 14+Kw of panels and not worry about troubling the dno, and I'm sure the powerwalls have export limitations. 
A powerwall for each phase would have seemed the logical choice, but I suppose everyone has their financial limits for a project.

Pro bono, or free help, is exactly what the forum is about, it's why we all help each other when we can.

Screwdriva

Solarchaser said:

Haha, of course fogstar wasn't considered, you love a powerwall.

Guilty as charged! It may surprise you to learn that the decision to go with the PW3 had nothing to do with my preference but rather the homeowner's desire to maximize odds of achieving the highest DNO approval (for the quickest return). When I met Tesla UK, they shared that they had invested heavily in educating utility provider staff on the merits of its system and I believe this has paid Telsa owners a rich dividend. Out of the dozen or so PW3s I've helped with, only 1 has not received the full 11.04kWh approval. 

Solarchaser said:

If that's not the house, I'm surprised you haven't got more on the house.

It's a period property in a really posh location and the village planning officer was the homeowner's immediate neighbour. The pool house you see pictured was a very recent construction concealed behind the main home, reducing risk of any external objection. 

Solarchaser said:

A powerwall for each phase would have seemed the logical choice, but I suppose everyone has their financial limits for a project.

I was the one who advised against this (and still am). I believe the homeowner can halve their consumption with relatively simple measures (LEDs to replace the 200 odd halogen bulbs as a first step). My hope is to delay the need for more battery/ expansion packs till the heat pump arrives. 

Solarchaser said:

Pro bono, or free help, is exactly what the forum is about, it's why we all help each other when we can.

Must convince the Mrs. to sign up to MSE too! Right now all I hear is "you should charge for this" and "who's that on the phone" or "You're no Martin' Lewis!!"

Heedtheadvice

Come on guys  do get your measurements correct! Especially if you advise people....

I assume you mean 22kWp i.e. max typical power generation ( not kWh )

Max kWh in a day ought to be close to 125kWh ( to boil the swimming  pool? )

Screwdriva

Heedtheadvice said:

Come on guys  do get your measurements correct! Especially if you advise people....

I assume you mean 22kWp i.e. max typical power generation ( not kWh )

Max kWh in a day ought to be close to 125kWh ( to boil the swimming  pool? )

Technically, it's 22.6kWp + albedo. Realistically, they should see 22kWh for a 2-3 hours on clear summer days.

Martyn1981

Heedtheadvice said:

Come on guys  do get your measurements correct! Especially if you advise people....

I assume you mean 22kWp i.e. max typical power generation ( not kWh )

Max kWh in a day ought to be close to 125kWh ( to boil the swimming  pool? )

Yep, but if I can be cheekily pedantic, I think you meant 22kW (the DNO export limit), not 22kWp (the approx system size).