Solar plus Battery Quotes

TooCautious

Good Morning All

I've recently received quotes from three installers and wondered if you good people could comment as to the costs and equipment quoted for.

For context we are a four person household, using 5500kWh per year. Kids are early twenties so we'll have them at home for a few more years. Wife and myself expect to retire in three to five years, when I suppose our usage pattern will change a bit.

COMPANY A
14 x Jinko Tiger Neo 435W N Type All Black Mono Panels

G3 GivEnergy 5kW hybrid inverter

Gen2 GivEnergy 9.5kWh LiFePO4 Battery (integrated DC breaker)
£9961.00
(Would a 5kW inverter be about right for this system?)

COMPANY B

16 x 400w All Black SunTech Ultra V Panels

Dyness Powerwall 9.6kW

Hybrid Inverter (Sized Accordingly) 
£11195.00

COMPANY C
16 x JA Solar 400w Black Modules
1 x Solis 6kW EH1 Hybrid Inverter
1 x LG Chem 10kWh Li-ion Battery
£11375.00
Enviroguard Solar Shield bird protection +£640

All prices include scaffolding, installation, G99 application, MSC registration.

Many Thanks.

Netexporter

I'd go for A. Efficient panels with good warranty. Having same brand of inverter and battery will ensure better control and monitoring. The  inverter is sized 20% below peak, which is about right. You will get a bit of clipping in ideal conditions but better overall performance over the year.

I'd ask about the Gateway All-in-One battery. Much better performance and automatic islanding in the event of a power cut. (there may be DNO reasons why they are not specifying that, although the inverter puts you in G99 territory on its own)

Screwdriva

Agree with Netexporter, Of the 3, A is the best quote and the All in One is a better battery.

That said, I would never install Junko panels on my roof. Always go with panels from reputed, quality brands like REC/ Solarwatt/ Panasonic/ Hyundai/ Sharp/ Eurener/ REA/ Meyer Burger etc. even if confirmation bias from existing owners says otherwise. Insist that your installer swaps to any of the above and go for it! 

TooCautious

Netexporter and Screwdriva, thanks for your comments.

Differing opinions on the Jinko panels there. Still, that's why I'm asking.

I will ask about alternative panels. Is there any other advantage to the AIO battery option other than islanding?

If the additional cost for alternative panels or the AIO option is prohibitive, is this still a good system?

Neither of you commented on the price of Quote A so I assume it's competitive as is?

Thanks.

Netexporter

Differing opinions on the Jinko panels there. Still, that's why I'm asking.

I agree with Screwdriver that the panels he suggests are very good, however, I don't think Jinko would be offering the long performance and materials warranties if they weren't pretty confident in their product. Also, the Jinko panels are N-type, rather than P-type, so are more efficient than most.

Is there any other advantage to the AIO battery option other than islanding?

The output and charging rate are both 6kW. You can fill faster when the sun is shining and, more importantly, you can more-or-less run the house as normal in a power cut, whereas you'll only have an emergency socket to run essential things like the fridge/router with the smaller battery. The A-i-O isn't all that much more money than the 9.5 battery. It has the same performance as a Tesla Powerwall but for considerably less cash.

Neither of you commented on the price of Quote A so I assume it's competitive as is?

The price of panels has dropped considerably, in recent times. Assuming we are back to the pre-Ukraine benchmark of £1000/kWp, then the panels and inverter are about £6k, leaving £4k for the battery. I've seen quotes for the A-I-O, alone, for £8k. As the cost of getting the people there is already accounted for, there being zero VAT for installation with a new PV system, then I reckon you wouldn't be far adrift from price of the other two quotes, for a much better system.

I suspect B & C are pricing with a view to there being some haggling. If A have good reviews I think I'd save myself the hassle.

Screwdriva

Netexporter said:

Differing opinions on the Jinko panels there. Still, that's why I'm asking.

I agree with Screwdriver that the panels he suggests are very good, however, I don't think Jinko would be offering the long performance and materials warranties if they weren't pretty confident in their product. Also, the Jinko panels are N-type, rather than P-type, so are more efficient than most.

Thought I'd share the summary from the NREL's study on panel degradation below. Topping the list of panel performance degradation...you guessed it...Junko!

Not the same panel of course but from the same manufacturer/ brand. I wouldn't trust any brand other than the list I shared above, no matter what an installer tries to sell you. Remember, you're going to be living with the system for decades (assuming you don't move). Go with the brands that promise the best odds of maximizing peace of mind.

Agree with NE about the All In One being the better option assuming they don't increase your cost substantially. Otherwise, the setup you have been quoted is fine (minus the panels).

Netexporter

Not the same panel of course but from the same manufacturer/ brand

Totally different technology, though. Are manufacturers not allowed to make progress/improvements? 

Perhaps Jinko have taken note of the findings of the survey and taken steps to address the degradation issue? There doesn't seem to be any suggestion that there was anything mechanically wrong with their old panels, just the cell technology was sub-optimal.

Screwdriva

Netexporter said:

Not the same panel of course but from the same manufacturer/ brand

Totally different technology, though. Are manufacturers not allowed to make progress/improvements? 

Perhaps Jinko have taken note of the findings of the survey and taken steps to address the degradation issue? There doesn't seem to be any suggestion that there was anything mechanically wrong with their old panels, just the cell technology was sub-optimal.

I admire your optimism!  

QrizB

Screwdriva said:

Netexporter said:

Differing opinions on the Jinko panels there. Still, that's why I'm asking.

I agree with Screwdriver that the panels he suggests are very good, however, I don't think Jinko would be offering the long performance and materials warranties if they weren't pretty confident in their product. Also, the Jinko panels are N-type, rather than P-type, so are more efficient than most.

Thought I'd share the summary from the NREL's study on panel degradation below. Topping the list of panel performance degradation...you guessed it...Junko!

Here's a more recent table from the same study.

At Sandia, the LGs are faring poorly - almost as bad as the Jinko's, which are themselves mid-table - while the Trina panels are outperforming their nameplate.

Screwdriva

QrizB said:

Here's a more recent table from the same study.

I think you've shared this before? Regardless, the difference in the two is the location. If memory serves, study 1 from 2021 used Colorado as a location and the newer version used a dry, warmer desert climate of New Mexico? 

I don't see how the latter would apply to the UK climate but maybe you do?

Netexporter

As I said earlier, I don't think they would offer such a long guarantee if they weren't reasonably confident. Most domestic users probably wouldn't monitor the degradation (nutters here excepted, of course!) but commercial solar farms certainly would. It could cost them a tidy sum if big operators started making claims against them.