New solar installation - comparing options - advice welcomed

[Iceandsolar]

Hi, I live in the south of England and have been getting quotes for Solar panels and battery. No immediate plans for an EV. The panels would be on an east facing roof at approx 35 degrees. Annual usage approx 3500kw. I have 3 quotes that I would welcome opinions on. Is the Tesla powerwall worth the extra cost or are the batteries in the other 2 quotes still effective and reliable? Option 3 does not include birdprotection but the system has an insurance backed guarantee on the panels and battery. Any useful comments would be welcome. Thanks.



Option 1 5.16 KW System with Givenergy - approx £15300

12 x JKM430N-54HL4R-B 430 Watt Panels (Jinko Solar Co., Ltd.)
12 x IQ7PLUS-72-2-INT (Enphase Energy Inc.)
1 x Giv-Bat9.5 (GivEnergy)
1 x GIV-WAR-10Y-AC3.0, 1 x Scaffold 2 Storey , 1 x Giv-AC3.0, 12 x Birdguard - Black Coated Mesh, 1 x ENVOY-S-METERED-3PH, 1 x Enlighten



Option 2 5.16 KW System with Tesla Powerwall 2 – approx. £18300

12 x JKM430N-54HL4R-B 430 Watt Panels (Jinko Solar Co., Ltd.)
12 x IQ7PLUS-72-2-INT (Enphase Energy Inc.)
1 x Tesla Powerwall 2.0 (Tesla) 1 x Powerwall Backup Gateway 2,
1 x Scaffold 2 Storey , 12 x Birdguard - Black Coated Mesh, 1 x ENVOY-S-METERED-3PH, 1 x Enlighten



Option 3 4.8KW System with SolarWatt panels and Huawei 10Kw battery – approx. £16K

12 x 400 SolarWatt Panels (Panel vision AM 4.0 (400 Wp) black) 4,278 kWh per yearInverter Huawei 3.68 kW Total Inverter Rating1 x SUN2000-3.68KTL-L1Huawei 10 kWh Total Battery Storage1 x LUNA2000-10-S0

Warranties;

Warranties: 30 Year Panel Product Warranty, 30 Year Panel Performance Warranty, 10 Year Inverter Product Warranty, 10 Year Battery Product Warranty

 

[bladerunnerpv]

Hi there, some queries on my part

-Why the microinverters in first two quotes but not the third? Microinverters are often used to combat shading problems.
-What shading factor has been indicated for all three quotes?
-Any reason for no west-facing panels?
-Roof is 35deg pitch with respect to the horizontal?
-Arrangement of strings of panels - 2 strings of 6 panels in series?

Suggest you ask about the power level provided to the house, especially when coming from battery, as with east only panels it sounds like you will be relying on battery for evening dinner time power? For context a toaster is quite power hungry and commonly 3kW, although 2kW models are around

1st quote, IIRC the Giv AC 3.0 supplies 2.5kW to the house from battery.

There is an all-in-one system in the offing, providing higher output and also power cut backup with an additional widget. Quite TESLA-esque. Take a look at the givenergy website for more info.

2nd quote, IIRC the tesla gateway enables supply in event of power cut, think output of 3.6kW,

Tesla are expensive, some are concerned about the battery materials and ethical mining thereof, not sure how much is real and how much is marketing by other companies.

3rd quote, a quick read of the inverter indicates the inverter has max discharge power of 3.68kW from huawei battery supply. Worth checking if the 5kW version of the inverter can be limited to 3.6kW for grid output via the inverter settings, you'll appreciate the extra kW provided to the house from a larger inverter. If I read it correctly huawei cannot provide supply in event of power cut.

https://midsummerwholesale.co.uk/pdfs/huawei-sun2000-2-6ktl-l1-datasheet.pdf
Note this is from looking at specs and reading forums and blogs. Don't take my word for all of it!

 

[Iceandsolar]

Thanks Bladerunnerpv for you comments. I am new to this and so all advice is useful to me.

My east facing roof and is clear from shading problems. At this stage I wouldn't consider panels on the west facing side of the roof because of aesthetics/neighbours. The 35 deg roof pitch is from the horizontal.

The third option uses 2 strings of panels.

I think that the Solarwatt panels (Option 3) are probably better than the Jinko Tiger (Options 1 and 2) as the Solarwatt are glass backed and come with a 30 year guarantee. I am new to all this so if anyone disagrees then please say. With Option 3 the only option they offer is the Huawei batteries which do not come on in the event of a grid failure.

Options 1 and 3 are quite similar in pricing. Perhaps I would regret not going for the Tesla Powerwall but it is more expensive and I don't know if it is worth the extra outlay.

 

[bladerunnerpv]

You're welcome Iceandsolar

Option1:
12 x IQ7PLUS-72-2-INT (Enphase Energy Inc.)
microinverters are generally a more expensive way to provide PV inverter (DC from PV to AC) IQ7+ is £140 ea. wholesale

You might save some money by considering a DC coupled inverter such as the Gen 3 Giv 5kW, which apparently has higher (battery) output than the AC coupled version and an automatic power cut backup capability

AC coupled : 12x ~£140 IQ7plus + £950 Giv AC3.0 is ~£2350
DC coupled : ~£1400 wholesale, PV plugs into the inverter

Deege solar had some useful blogs on DC and AC coupled

All these companies tie you in to their own batteries AFAIK, it's worth checking if there is an upper limit on battery storage or facility to add extra. Over the 9 months or so I've looked at this stuff I've seen some kit discontinued and new kit introduced from various manufacturers, so in practise there's probably a time window on the 'add extra battery storage later' option. I suspect the chance of finding matching batteries in say 5yrs time could well be zero!

Solar won't give much output over winter, you'll probably find yourself charging battery up on economy7 or equivalent and using during the day

One other thing to look at is the startup voltage of the inverter - the PV output needs to exceed this before the energy can be used, ask the installers what this is, in general the lower the better. Not sure how microinverters compare in this respect.

Others on the forum know more about all this stuff than I've managed to learn so far...