Solar & battery quote

miek

Hi,

Looking for some input on cost of our intended PV system...

South coast,18 panels on south facing (165dg) roof, no shading.

All electric, annual usage 6000kWh (when being very, very tight with electric heating and DHW!), new smart meter, currently Octopus flexible. No EV. 

We have been looking at various PV systems over the last 6 months and settled on Sunsynk.
G99 approved with 8kW export limit.

We have been quoted £13k-£15k from several (local) installers for the following system:

Synsynk Ecco 8.8kW inverter
2x 5.32kW Sunsynk batteries
18 panels (395-435W various brands), no optimisers
fastensol roof system 
no hot water diverter (will be provided by inverter)
bird proofing
Various other bits & pieces required for install
Scaffolding (2 storey building)

Labour, MSC, NICEIC etc.

Only one company provided a detailed breakdown: Seems roughly £10k equipment and £4k service/labour cost (all ex vat)
Cheapest online prices for the above inverter + 2 batteries: £4350 (ex vat) at the moment, £1k lower than on the quote.

Does that seem about right? I was hoping we would be more towards the £11-12k mark....but that might be wishful thinking! 

Netexporter

I'd say the price is in the right ballpark. However, the inverter looks a bit big for the array size. The general practice is to size the inverter at about 80% of the peak array output. You will get some clipping, in ideal conditions, but that is outweighed by gains in earlier start-up in sub-optimal conditions.

miek

Thanks netexporter - much appreciated.
The smaller inverter is only 5kW so likely fair bit of clipping. The start up voltage for both inverters is the same I understand (per the Sunsynk technical team) so should not make much difference?.  

Netexporter

I'm proposing to have a 5kW inverter with my 8kWp array, although being in Mid Wales, where overcast is the norm, I don't think clipping losses will be too significant. Perhaps on the south coast a larger inverter would give a better result, overall. Are you actually within sight of the sea? If so, the reflected light may increase you potential panel output.

miek

I think it is not so much of a problem with the newer inverters as I understand it, I don't think you need to undersize the inverters anymore? Our peak power demand will also exceed 5kW at times as will our export on a sunny day when we are not in. Yes, we are close to the sea - 2ish miles, but not in sight of..  

Screwdriva

Any reasoning for deciding on Sunsynk? 

miek

We looked at Growatt initially but left that option pretty early on. Then looked at Give energy but felt Sunsynk was more versatile / cost effective and the system is compatible with different batteries if we wanted to add more in the future. 

Screwdriva

miek said:

We looked at Growatt initially but left that option pretty early on. Then looked at Give energy but felt Sunsynk was more versatile / cost effective and the system is compatible with different batteries if we wanted to add more in the future. 

While I will concede that Sunsynk is a vastly superior option to Growatt, and have an equally responsive UK based tech support team as GivEnergy do, my vote always goes to Fronius, Enphase or SolarEdge inverters, especially at the price point shared. A recent quote I've seen that may provide useful perspective:

18 X Sharp 420W panels w/ 30 year performance warranty
18 X SolarEdge optimizers
  1 X SolarEdge 8kW inverter w/ 20 year warranty
  1 X GivEnergy All in One 13.5kW battery w/ 12 year warranty

~£14.5K installed. G99. HIES & bird netting included. 

Given the multiple benefits of optimizers + the 30% increase in storage capacity and arguably superior brands, might be worth a review?

miek

Thanks for your reply Srewdriva. We did get 2 Solaredge quote's but they were way out of budget (£16k+) although I cannot remember the batteries on the quotes. The 13.5 all in one was not yet available I think at the time! Giveenergy support was poor when I called with some questions on 2 occasions so that put me off a bit. I’m kind of a bit averse to restart the research process again…the more I read the more confused I get! Having said that….might dig said Solar edge quote out and ask for another one!