Advice on quoted inverter size 3.6kw

slewis1972

Starting getting some quotes as moving into a new place and want solar.

My current consumption is 4500 kWh ( no EV as yet but wife works from home hence washing machine etc always generally on).

One quote is 10 x 450 panels but the inverter is the smallest:

solar Growatt 3.6kw inverter

With a growatt 6.5KW battery.

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Plan is , 5 panels South facing, 5 panels South east. Shading not an issue.

Should I go for a larger inverter but not sure its an option.

Other quotes are for more panels but smaller  maxtoimum sun eg 12>14 and one has even suggested close to 10kw battery with 5 and 6 kw Inverters quoted. Costs go up though

Any info appreciated.

DougMLancs

You are best off getting as much power up there as you can. A standard 3.68kW inverter would be well-matched if you just went for those 10x450W panels (although I would personally avoid Growatt). What’s the highest total output of panels you’ve been quoted? The cost of a larger array and matching inverter will be relatively small and you’ll regret it later if you don’t. I would rather have more panels and no battery than the other way around- especially with Flux on offer.

Screwdriva

A 10 X Sharp 410W Panel System + optimizers + SolarEdge inverter should cost you no more than £5800 installed (with 20 year warranty included). If you're convinced you really want a battery, you have a few options. 

That said, I would skip it and just sell your excess to the grid via Octopus Flux. 

slewis1972

So, what I have:

Supplier 1:, 

13 x 410KW (Sharp), Fox ox Hybrid ESS inverter and 5.33KWh Fox battery, iboost, manual change over (if we get a powercut) bird protection: £12k give or take.

Like the Fox batteries as stackable as neighbour has them.

Supplier 2.

14 x Trina Solar 425W, Solis 5G 6.0kW 230V Hybrid Inverter, 2 x Pylontech US5000 4.8kwh batteries, pigeon, G99 - close to £17k

Supplier 3.

10 x 450w solar panel eurona Mepv 45, 1 x 3.6kw growatt inverter, 1 x 6.5kw growatt battery , iboost, bird protection - £11k.

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I have 2 x older kids at home and potentially getting a EV in next few years so think I do need to get a battery to forward plan.

Any thoughts appreciated.

Magnitio

All of those quotes seem very high to me. Whereabouts are you located?
Not sure that having a battery because you have an EV necessarily makes sense, but it depends on when you can charge the EV and what tariff you choose. I'm sure others on this forum who have EV's and batteries may help here.

Screwdriva

A few thoughts:

1) I would argue in favour of maxing the number of panels (both Eurener and Sharp make excellent panels) , so go with 14 if they'll fit.
2) Definitely swap the Chinese inverter brands with something like SolarEdge, as they honour warranty claims. 
3) Pylontech batteries are quite popular and are stackable. You can pair them with a SolarEdge inverter via a AC/DC controller. 

All in should be ~ £11K installed for the above!

That said, I would suggest waiting on the battery and save the £ today. You can always add one later with one extra panel and pay 0 VAT. Batteries are improving dramatically each year.

slewis1972

Thanks, located in South East (Surrey).

Battery not just for EV, wife works from home so in winter, with lack of solar, using the flux tariff possible save to top up battery etc.

Quite complex indeed, certainly want a brand that has good customer service to future proof as much as possible

fishfienduk

I have the foxess equipment, it has run flawlessly for nearly 2 years, the inverter will output 5kws around 21amps from battery without drawing from the grid, although you may need another battery for that as they have a maximum draw. They are also high voltage and are wired in series so have fewer losses. The app is not so good, but there is a community on Facebook which has developed a modbus link with easy to follow instructions, and like you said, it's modular, so you can add more if you desire. The batteries have 10 yr warranty as does the inverter. They also have a UK service branch in Manchester I believe. One phone call was all it took to update my firmware. I was going to go for Givenergy, but the output was limited from the inverter, so I went with Foxess.. I'm happy, but all subjective really...