Solar Panels with Battery - Advise on options and questions please

jatinmistry_uk

I have been thinking and finally decided to get the solar with battery following yet another increase in prices.  It will only get expensive!  If not cost I know why not many having this and it's because everything is so confusing.  So I very much would appreciate if you can help please?

The house is a semi detached property with 4 bedroom and annual consumption is 4000 kWh electric.  Have got Gas for heating but heat pump is step too far!  We have got quote from 3 companies as follows.

Taking cost and value into consideration, would you say Fresh Water is right option?  Also, my electric meter is in house under the stairs and don't think the converter and battery will fit there.  Can I ask them to fit outside at the back where it's shaded or would they install in the loft?  Do I need to do anything else if installed there?  Finally, I keep reading about G99 but does not make sense.  Would that effect me and if so, can you please help understand?

Company	Glow Green (MSE)	Effective Home (BG)	Fresh Solar (Costco)
Number of Panels	8	8	10
System Output	3.71 kW	3.6 kW	4.5
Panels	DMEGC Infinity RT	DMEGC Infinity RT	Eurener Panels
Panel Warranty	25	25	25
Inverter	Fox ESS H1 G2 3.0	Sunsynk 3.6	Fox Retrofit
Battery Type	Fox ESS EP6-H	Sunsynk	Fox ESS EP6
Battery Capacity	5.7 kWh	5.32 kWh	5.36 kWh
Bird Netting	?	?	Yes
System Cost	£7,150.47	£8,395.00	£6,799.00
Installation/scaffolding	£0.00	£0.00	£350.00
Grand Total	£7,150.47	£8,395.00	£7,149.00

QrizB

Of those three options, I agree that Fresh Solar appears to be the better choice.

The Fox ESS EP6 is apparently suitable for outdoor installation so yes, your installers might be able to put it on the rear of your house. This might add a little to the cost of the installation.

Your installer will deal with the G99 application.

Qyburn

jatinmistry_uk said:

Finally, I keep reading about G99 but does not make sense.  Would that effect me and if so, can you please help understand?

G.99 is the approval process to allow you to connect something that generates more than 3.68kW.  Actually I think it's strictly 16A that's the threshold. 

Below that power the process is G.98, which just consists of telling them what you've installed. It can't be refused.

Above that threshold you have to ask permission prior to commissioning, which is the G.99 process.

Some installers can't be arsed so won't quote anything above G.98 power.

Screwdriva

None of the batteries in the quotes offer whole house backup in the event of the blackout and they are too small to cover household demand especially during the colder months. Also, Fox doesn't have the best reputation.

At 4000 kWh per annum and no chance of a heatpump on the horizon, I would suggest that your consumption is right at the threshold where a battery starts to make sense.

Option1) If you skip the battery altogether, consider a 10 X 500W Eurener bifacial panels (5kWp) paired to a 5kW SolarEdge system for around ~£5K installed. It's a larger, superior system with a better app and warranty (20 years) compared to all 3 quotes, and you can use the grid as a virtual battery to sell to at ~15p per kWh. 

Option 2) If you are determined to get a battery, why not invest in a vastly superior battery inverter that covers all of your household's consumption, offers whole house backup, has an unparalleled track record and gives you access to the Intelligent Flux tariff, which may lead to a faster return on investment despite the higher upfront cost? 

10 X 500W Eurener Bifacial Panels (5kWp) paired to a 13.5kW Tesla PW3, which should cost no more than £10.5K installed in 2025. 

QrizB

It's not entirely clear to me how Screwdriva has calculated that 8 x 500W (=4000W) Eurener panels work out to be 5kW, and produce more power than 10 x 450W (=4500W) ones. Perhaps he can explain. Now edited!

If you've got room for 10 panels, can you ask Fresh Solar if they can fit 10 x 500W ones instead? The 500W ones are longer than the 450W ones, so it's possible they won't fit your roof.

Screwdriva

QrizB said:

It's not entirely clear to me how Screwdriva has calculated that 8 x 500W (=4000W) Eurener panels work out to be 5kW, and produce more power than 10 x 450W (=4500W) ones. Perhaps he can explain.

If you've got room for 10 panels, can you ask Fresh Solar if they can fit 10 x 500W ones instead? The 500W ones are longer than the 450W ones, so it's possible they won't fit your roof.

Whoopsie. It should be 10 X 500W (not 8). Edited. It's late and I've had one more single malt than I should have .

The 500W Eurener bifacial are < 15 cm longer than the 450W DMEG (same width), so fit in the vast majority of installations. 

jatinmistry_uk

Thank you for advise.  I have looked at the consumption and battery makes sense  500w panels will not fit on the roof and I have approached couple of local installers with good reviews and looking at the website.  I have been quoted £8.2k for:

• 12 X Aiko 475 panels with 25 years warranty
• Fox ESS H1 Series G2 Hybrid 5 kW Inverter with 10 years warranty
• Fox ESS EP12 Plus 11.52 kWh battery with 10 years warranty
• 1 X TS4-A-0 Module-level PV Optimizer
• Bird Deterrent Mesh
• G99 application
• Installation
• Scaffoldings

The quote says these likely to generate 4.2k kWh against my annual consumption of 4k.

They have also said it will be £10.5k if I were to replace with Tesla option which is about £2.3k difference.  Although I am sure Tesla is better option in terms of quality but in terms of what I am getting I feel suffice.  Also our budget was around £8-£8.5 and Tesla will be too much of stretch unless if anyone here advises strongly against?

Also I did ask about installation only to start after G99 approval.  Any advise what happens if it refused?

Screwdriva

I have already shared several reasons not to go for Fox and to go for the PW3. For your benefit, I'll summarize my own thoughts:

1) Fox = poor reviews, poor aftersales and poor software.  Tesla = best in class. 
2) Fox does not qualify for the Intelligent Flux tariff. Tesla does. 
3) This installer's view on Fox summarizes what type of installer has historically offered this kit better than I can. 

I would suggest asking the installer to:

1) Swap out the Aiko panels for Eurener 475W bifacial panels. They perform better in real world conditions and are ethically made in the EU. 
2) Swap out Fox for the PW3. You are attempting to equate two vastly different brands by focusing on price. Don't fall for the false economy the Fox quotes presents. There is a £750 rebate for the PW3 from Tesla to all installers - remind your installer of this.

Expect to pay < £11K for everything all inclusive. Despite the 25% higher upfront cost, it will outperform the Fox system and deliver a better ROI (thanks to the IOF tariff) and give you many more years of hassle free service.