PV & Battery advice

[1adrianmonks]

Hi, new to this forum.

Looking for help analysing a quote for vfm and getting advice on how to spec a good system.

I have 12000-13000Kwh consumption; with an EV and a Hot Tub above normal household stuff.

The hot tub uses a lot of energy in winter… when sun is not great.

Main Roof is west facing (92 degree from south). It can hold 18 panels.
The east facing roof cannot hold many panels; so focus is on single roof side.
Not much shade; 0.94 factor assumed.
House is in south Bedfordshire.

The quote I got was > £18k for:
18x Trina Veryex 415w panels
1xSolax c1 G4 7.5d hybrid inverter
2xSolax 5.8kwh Battery (11.6 total)
iBoost
Zappi EV charger
And ancillaries.
No optimisers.

The solar generation forecast is 5515kwh pa

Key questions and advice:

1. Components assumed: anyone advise if the above spec’d components are good (panels, battery, inverter) or recommend better components? I know very little.

I watched a recent video from EV man who strongly recommended GivEnergy for the all in one battery/inverter/system.

2. Anyone have a view on the setup?
Battery size about right?
Any way to generate more solar power with limitations of a west facing roof?
I don’t know numbers but I must use a lot of power if I have the hot tub heating at night and EV charging and set washing machine/dryers. Can I charge the battery on cheap rates and have heavy consumption?

3) view on vfm of the quote or on the company …. Rainbow.

4) any recommended alternative installers in the region of beds/herts … or how to get a better vfm quote?

5) to future proof for vehicle to home (3 years away for me) what should I spec differently?

I have a million and one other questions but these are at the forefront of my mind.

Thanks in advance
Adrian

 

[johnb2713]

Hi, new to this forum.

Welcome

Looking for help analysing a quote for vfm and getting advice on how to spec a good system.

I have 12000-13000Kwh consumption; with an EV and a Hot Tub above normal household stuff.

If not already done, install a heatpump for the hot tub, it will use 1/3 the electrical energy to heat it. There are some Mitsubishi almost new Ecodan units on ebay at the minute, 11kW @ £2k, absolute bargain

The hot tub uses a lot of energy in winter… when sun is not great.

Main Roof is west facing (92 degree from south). It can hold 18 panels.
The east facing roof cannot hold many panels; so focus is on single roof side.
Not much shade; 0.94 factor assumed.
House is in south Bedfordshire.

I have a mix of panels on South and West facing roofs. The West facing comes into play from later morning through well into the evening. Your East facing roof should work from sunrise to well into the afternoon, dependent on shading etc. Bright days still provide good generation, it doesnt have to be clear skies / no cloud (it is obviously better).

The quote I got was > £18k for:
18x Trina Veryex 415w panels
1xSolax c1 G4 7.5d hybrid inverter
2xSolax 5.8kwh Battery (11.6 total)
iBoost
Zappi EV charger
And ancillaries.
No optimisers.

It seems an odd choice to install iboost when you have Zappi in there. MyEnergi's EDDI would be a better choice and integrates with solar and ZAPPI very well, all controlled via the MyEnergi app. EDDI is a little more expensive but seemingly more reliable than iboost too.

The solar generation forecast is 5515kwh pa

Key questions and advice:

1. Components assumed: anyone advise if the above spec’d components are good (panels, battery, inverter) or recommend better components? I know very little.

I watched a recent video from EV man who strongly recommended GivEnergy for the all in one battery/inverter/system.

What ever youre comfortable with, I suspect the all in one product may carry a price premium and possibly may limit future choices with batteries etc.

2. Anyone have a view on the setup?
Battery size about right?

Get the biggest battery that your budget allows.

Any way to generate more solar power with limitations of a west facing roof?
I don’t know numbers but I must use a lot of power if I have the hot tub heating at night and EV charging and set washing machine/dryers. Can I charge the battery on cheap rates and have heavy consumption?

If you have a compatible EV OR Compatible Wallbox, go on Octopus Intelligent (message me if you want a code that pays you and me £50!). 6 hours of off peak energy at 7.5p kWh and other times through the day that Octopus control. Peak rate is around 38.5p

3) view on vfm of the quote or on the company …. Rainbow.

Have a look at other quotes, I can put you in touch with a system architect who will give you an alternative quote.

4) any recommended alternative installers in the region of beds/herts … or how to get a better vfm quote?

contact this guy directly, great knowledge etc, he has planned and installed for several friends and family, good prices, good design, great advice:-

RYAN OLIVER
Senior Technical Designer
07855313850
[email protected]

5) to future proof for vehicle to home (3 years away for me) what should I spec differently?

It's not possible

I have a million and one other questions but these are at the forefront of my mind.

Feel free to ask more and do keep us updated on your installation etc.

 

[Kot]

a guide to equipment costs etc use the free, easy-pv.co.uk you can then play around with modules on all your roofs and inverters/batteries etc see what the generation could be etc.
Most armchair surveyors use this or similar google earth maps to generate quotes from a picture of your roof and aspect
But ensure you avoid armchair surveys lol

 

[johnb2713]

Most armchair surveyors use this or similar google earth maps to generate quotes from a picture of your roof and aspect

Mine was done this way and the measurements were amazingly accurate, i'm sure better than a site visit without climbing on the roof.

But ensure you avoid armchair surveys lol

My experience suggests otherwise, no problems for myself or others that have had surveys done this way.

 

[bladerunnerpv]

Yes, recommend get 3 quotes with site visit.

I had one quote recently that claimed the two sides of the roof were different sizes, from using Google maps, didn't seem to understand that the satellite wasn't directly overhead so the appearance on each half wouldn't be the same!

 

[bladerunnerpv]

Another thumbs up for easy-pv.

It's not clever enough yet to simulate charging battery overnight from economy7 though.

also pvgis worth a look

 

[Kot]

Mine was done this way and the measurements were amazingly accurate, i'm sure better than a site visit without climbing on the roof.


My experience suggests otherwise, no problems for myself or others that have had surveys done this way.

Yes I guess we all have different experiences, when simple trigonometry and measuring roof angle with your smart phone and using a tape measure is the way to go, instead of guessing the roof slope etc
Saying that I had 1 company send me a email saying there is already panels on the roof!!! yes you guessed it they quoted for my neighbours roof. Then they failed again picture of another neighbours roof lol. Then they put them on the east roof which is shaded all day.

But then on the other side, a surveyor turned up without a tape measure lol ??? counted the tiles and spaced it out by foot lol yes he was tin canned as well.
I must have had about 8 actual visits and more than 10 armchair quotes it really opens your eyes and reminds me of the double glazing salesman days.

 

[bladerunnerpv]

Also, not sure givenergy aio is released yet?

https://www.givenergy.co.uk/products#giv-all-in-one
Will be interesting to see final spec and system.

Are they still British owned?

 

[1adrianmonks]

Welcome


If not already done, install a heatpump for the hot tub, it will use 1/3 the electrical energy to heat it. There are some Mitsubishi almost new Ecodan units on ebay at the minute, 11kW @ £2k, absolute bargain


I have a mix of panels on South and West facing roofs. The West facing comes into play from later morning through well into the evening. Your East facing roof should work from sunrise to well into the afternoon, dependent on shading etc. Bright days still provide good generation, it doesnt have to be clear skies / no cloud (it is obviously better).


It seems an odd choice to install iboost when you have Zappi in there. MyEnergi's EDDI would be a better choice and integrates with solar and ZAPPI very well, all controlled via the MyEnergi app. EDDI is a little more expensive but seemingly more reliable than iboost too.


What ever youre comfortable with, I suspect the all in one product may carry a price premium and possibly may limit future choices with batteries etc.



Get the biggest battery that your budget allows.


If you have a compatible EV OR Compatible Wallbox, go on Octopus Intelligent (message me if you want a code that pays you and me £50!). 6 hours of off peak energy at 7.5p kWh and other times through the day that Octopus control. Peak rate is around 38.5p

Have a look at other quotes, I can put you in touch with a system architect who will give you an alternative quote.


contact this guy directly, great knowledge etc, he has planned and installed for several friends and family, good prices, good design, great advice:-

RYAN OLIVER
Senior Technical Designer
07855313850
[email protected]



It's not possible


Feel free to ask more and do keep us updated on your installation etc.

Wow so much rich info in here.

I didn’t know about heat pumps for hot tubs … wasn’t a thing when I got it so very long ago and none of my friends have done that.
Have googled somewhat in my lunch and see that example. 2k ex vat on eBay and then I’d need to get it fitted.

I’ll look into Eddi; spotted other recommendations about that too

I am definitely going to switch to Octopus agile; albeit I need a smart meter fitted too. Seems a no brainier even without the wider system.

I am wondering about the solar v battery aspects…. Of course biggest battery I can afford, but would you trade solar for more battery … or even go for a bigger battery and the hot tub heat pump and no solar?? If something had to give, should I be prioritising solar, battery or hot tub heat pump !??

Thanks for the architect recommendation too; someone like that I’m sure can help me work those aspects out.

 

[1adrianmonks]

a guide to equipment costs etc use the free, easy-pv.co.uk you can then play around with modules on all your roofs and inverters/batteries etc see what the generation could be etc.
Most armchair surveyors use this or similar google earth maps to generate quotes from a picture of your roof and aspect
But ensure you avoid armchair surveys lol

Thanks I’ll look this up and have a go this weekend.

 

[1adrianmonks]

Also, not sure givenergy aio is released yet?

https://www.givenergy.co.uk/products#giv-all-in-one
Will be interesting to see final spec and system.

Are they still British owned?

They emailed me back on that question to say it’s being released very soon … likely this week !

They are British I believe too.

 

[johnb2713]

I am wondering about the solar v battery aspects…. Of course biggest battery I can afford, but would you trade solar for more battery … or even go for a bigger battery and the hot tub heat pump and no solar??

The above are a bit of a dilemma. Solar can be good in the decent weather but in winter time about as much use as a chocolate teapot. With Octopus off peak at 7.5p, Solar-PV would have a very long break even point. If I were in your position, I would be looking at more battery storage and possibly bigger inverter, this would then allow you to run on 7.5p kWh throughout the day, recharging every night.
Definitely add the Heatpump, 11kw of heat for 2.5 kW of electrical energy has got to be a winner and it would be easy to plumb in to the hot tub pipework, the circulating pump just needs to pass the water through the heatpump unit.

If something had to give, should I be prioritising solar, battery or hot tub heat pump !??

Thanks for the architect recommendation too; someone like that I’m sure can help me work those aspects out.

 

[bladerunnerpv]

Sunamp Thermino might be worth a look for hot water needs.

 

[johnb2713]

Sunamp Thermino might be worth a look for hot water needs.

Expensive / long payback time compared to existing immersion and adding EDDI

 

[1adrianmonks]

Update… so I’m now in the process of convincing myself to go for a near term solution that focuses on
a) heat pump for hot tub … my local provider of my hot tub will supply and install for £1750 a 7.2kw one with very high performance.
B) a home battery system. Either the Givenergy all in one (13.5kw, 6kw in/out) for £8650 installed, or a Lux double squirrel pod (14.4kw uhome batteries, 7kw in/out) for £8.25k installed.

Solar will be a next step for me in the future.

So now I have a question… anyone got a vote on Givenergy Vs the Lux Power SQPOD? Both seem to have software that adapts automatically to Octopus agile, but Lux is slightly cheaper for slightly more storage and 7kw in/out Vs 6. So I think this edges it for me.

 

[johnb2713]

Update… so I’m now in the process of convincing myself to go for a near term solution that focuses on
a) heat pump for hot tub … my local provider of my hot tub will supply and install for £1750 a 7.2kw one with very high performance.

No brainer on this one, you should go with that.

B) a home battery system. Either the Givenergy all in one (13.5kw, 6kw in/out) for £8650 installed, or a Lux double squirrel pod (14.4kw uhome batteries, 7kw in/out) for £8.25k installed.

I personally would shy away from the all in one solutions, it makes future battery choice / upgrades more difficult. Batteries for Fogstar will cost you £1350 per 5kWh, they simply stand on top of each other and are rack style. Add an inverter of your choice I would recommend Victron Multiplus II GX, it's a quality machine, very well built, very robust and has a great technical support forum / followers world wide. Theyre circa £2k so that puts you at £6k leaving you with £2.5k to connect it up.

Solar will be a next step for me in the future.

Victron is excellent for this, all of their MPPT's / Inverters etc all talk to each other really well.

So now I have a question… anyone got a vote on Givenergy Vs the Lux Power SQPOD? Both seem to have software that adapts automatically to Octopus agile, but Lux is slightly cheaper for slightly more storage and 7kw in/out Vs 6. So I think this edges it for me.

I'm not convinced about the merits of agile, there are very few times when it's cheaper than Intelligent and the extra wear and tear on battery is it truly worthwhile? The times when prices are high for selling are the exact times when youre most likely to need the energy. I'm sure you will have researched this aspect but maybe just plot your usage against pricing and see exactly what you gain / lose.
My goal was to get away from Peak Rate energy and supply my house with off peak and solar. It really has worked for me and was a very worthwhile investment.

 

[bladerunnerpv]

Check the situation wrt VAT, IIRC no VAT if some solar PV is included

 

[johnb2713]

Check the situation wrt VAT, IIRC no VAT if some solar PV is included

Yes, good point, buy a couple of panels and save 20% on all of it

 

[1adrianmonks]

I know … it makes sense if I have the money … but the labour/scaffolding costs etc warrant a decent job … unless I buy 2 panels and stick them on my garage door/wall just to get the vat discount

 

[1adrianmonks]

Re Octopus intelligent Vs agile…
Agile is <17p from 22.30 last night to 6am and 11am-4pm. From 6am to 11am it’s peak is 24p and then from 4pm to 22.30 it’s peak is only briefly 35p, and is >30p for only 2 hours.

Intelligent is 41.65p 05.30 to 23.30 and 7.5p 23.30 to 05.30.

On the face of it Agile is much better …
Unless I can get pretty much everything to run off batteries for 05.30 to 23.30 and so I only incur the off peak costs.

So I would be best getting enough batteries to run solely from the off-peak intelligent tariff.

I assume there would be no “load” restrictions on doing EV charge via grid, plus house stuff (tumble dryer etc), plus charge batteries at full rate 7kw/hr.