Solar Panel & Battery Quote Advice

McKnze21

Hi

I am looking into having a Solar PV system along with battery installed and looking for some advice on quote comparison.

My estimated annual usage for electricity is 8585kWh & we currently own a 4 bedroom detached bungalow with a South West facing roof, 4 occupants in the house. We do not plan to move and see this as our forever home. We would be looking to make this long term investment to help with our energy bills and we would be looking to utilise the finance option for this.

One particular quote I have so far is the following:

• Solar Panels Aiko Energy (AIKO-A475-MCE54Mb) 5.7kW Total Module Power, 12x 475W Panels (Bird Proofing Included) 5,256kWh per year
• EcoFlow Single Phase Inverter 3.68kW, Ecoflow Technology Inc.  1 x EcoFlow PowerOcean (single-phase) Hybrid Inverter 3.68kW
• Battery, Ecoflow Technology Inc, 10.2 kWh Total Battery Storage, 1 x EcoFlow PowerOcean Battery (10KW)
• FREE EV CHARGER, EV CHARGER WILL BE A BRAND WE HAVE IN STOCK(NO SPECIFIC BRAND)(SUBJECT TO 100A SUPPLY)(up to 7M from Fuse Board)
• Scaffolding, Grid Charge & Installation Included

Total Cost £15,695
Monthly Payments £168 (Loan Interest Rate 5.90%, 10 Years, Total Payments £20,652.18)

Is this a good deal?
Is it good equipment?
Will this system be suffice for my annual usage? As my initial question was, I average £208 per month on Electricity so can I have a Solar PV system installed and pay less each month for the system and electricity usage combined, according to the above I can as it's £168 but I am sceptical...?

Any advice on this would be great!

Thanks!

debitcardmayhem

I feel it’s over priced, but @Screwdriva will correct me if I am wrong. I don’t think the finance charges will help in terms of TCI either.

Edit

The inverter looks a tad on the small side too, probably so the installers don’t have to apply for a G99

Screwdriva

McKnze21 said:

Is this a good deal?

No. It's an extremely poor quote, both in terms of price and quality of kit. 

@debitcardmayhemis spot on - the inverter is too small (cowboy installers don't like the paperwork involved with G99 applications). 

I'm not sure where you are located, but here is a comparable quote honoured by installers I use to help other MSE Forum members. 

12 X Eurener 500W Bifacial panels (6kWP)
  1 X Tesla Powerwall 3 with Gateway 2 (inverter set to 5kW)
  1 X Zappi EV Charger 

~£12.5K installed. Bird netting, G99 included. 

That's a 5% larger array with a non-Chinese owned panel brand installed with (arguably) the most capable battery inverter in the UK, all for £3K less. 

You can definitely do better than the above quote! 

McKnze21

Wow! Thanks for that response. Very much appreciated. 

Given my annual usage of 8585kwh, do you feel a solar system such as one you have quoted above would be a good enough spec to cover that usage?

We would definitely be looking for finance for this so really, if we can make the finance payments less than what we pay for electricity just now without a solar or system then it seems we could go ahead with this sooner rather than later. 

What sort of Solar system would cover this? Would the battery of 5kWh be enough? Also inverter size?

Martyn1981

debitcardmayhem said:

Edit

The inverter looks a tad on the small side too, probably so the installers don’t have to apply for a G99

Totally agree, undersizing more than 20% is extreme, unless panels split over multiple orientations.

However, a thought did occurr to me (bit of a long shot), but if the battery is DC side, then that can allow buffering, so long as the inverter can manage DC storage on top of max rating on the AC side. But this does require monitoring, since once the battery is full, generation will be clipped at the max AC rating.

For instance, I have 6.75kWp of panels connected to my 3.68kW inverter. DNO won't allow me more, as I already have another 2.2kW inverter. But I won't get clipping, so long as I use/export enough from the batts beforehand, for them to take the generation that's above 3.68kW. The inverter can process 3.68kW to AC, and 'redirect' up to 5kW to the batts DC. Once the batts are full, then my system will clip at 3.68kW.

Not recommending this approach, just suggesting it as a long shot reason for the 'too' undersized inverter.


@McKnze21- Seperate thought, but a 4 bedroom bungalow suggests to me having a big roof (or roofs) that would allow for more than ~6kWp of PV. If pine end / gable end roof, then I'd expect 2 very large roofs, so more potential from the SW roof? If hip-roofed, with 4 triangular roofs, then there may also be a SE facing roof that could be used too? Just a thought, as with PV, bigger is usually better.

NedS

Do you have a heat pump or an EV, or plan on getting either in the near future? Do you have a functioning smart meter that allows you to access smart tariffs?

You would probably need around 9kWp of installed solar on a south west facing roof (unshaded) to be able to generate the equivalent of your annual usage, so the first question is how many panels can you fit on that roof or how much generation can you squeeze out of your available roof space. This is the first thing I'd look to maximise.

Next up, even if you can generate roughly your annual consumption, most of it is generated in summer when you cannot use it, so a battery will help with that. Any battery brand that gives you access to the Octopus Intelligent Flux (IOF) tariff will be extremely beneficial to you (e.g, Tesla, SolarEdge, GivEnergy, Enphase). The Tesla is the market leader for a reason, and 13.5kWh battery is a far better option with your usage (5kWh is way too small for your usage).

So fill that roof with as many panels as possible (panels are cheap, and you only want scaffolding once) and get the Tesla battery, for around £12.5k (as quoted by @screwdriva) is a very good deal for quality kit that will meet your goals to reduce or eliminate your annual bill. If you do not have a reputable local installer who can match that then I recommend you message @screwdriva and allow them to get you talking with an installer.

Screwdriva

McKnze21 said:

Wow! Thanks for that response. Very much appreciated. 

Given my annual usage of 8585kwh, do you feel a solar system such as one you have quoted above would be a good enough spec to cover that usage?

We would definitely be looking for finance for this so really, if we can make the finance payments less than what we pay for electricity just now without a solar or system then it seems we could go ahead with this sooner rather than later. 

What sort of Solar system would cover this? Would the battery of 5kWh be enough? Also inverter size?

12 X 500W panels = 6kWP. On a SW aspect roof, I'd expect an annual generation of between 5-5500kWh, which won't cover the full 8600kWh consumption you currently have. 

BUT.....you will be able to purchase cheap energy from the grid (as low 7p per kWh on Intelligent Go EV tariff) and store 13.5kWh of it in the Tesla battery during the colder months. In the warmer peak generation months, you will be able to sell your excess solar for upwards of ~25p per kWh (currently on the Intelligent Flux tariff). This should make a huge dent in your annual energy costs.

If your roof has additional space on a South/ West or East facing aspect, then roughly 18 X 500W panels would generate as much as your shared annual usage. Feel free to share an image of your roof and some of us would be glad to share additional thoughts. 

I would suggest applying for a 0% interest credit card instead of seeking finance from an installer. The (often hidden) cost is factored into the final price as the quote above should highlight. 

McKnze21

So I do not have a heat pump or a EV charger, however I do plan in future to have an EV charger at least.

My house is 34 years old, 129 sqm gross internal floor area... I think there must be at least minimum 40-50m2 area on South West facing roof with absolutely no shade whatsoever other than the log burner flue.

I am based in Fife, Scotland.

Screwdriva

Sadly, the installers I use typically do not cover Scotland and charge a substantial premium to travel there if they do. (I am struggling to find an honest installer who covers the country and does not extort their customers)

debitcardmayhem

Not a recommendation, but found this  via Tesla and MCS sites https://www.thenaturalenergycompany.co.uk/
they are Premier installers for Tesla

Martyn1981

McKnze21 said:

So I do not have a heat pump or a EV charger, however I do plan in future to have an EV charger at least.

My house is 34 years old, 129 sqm gross internal floor area... I think there must be at least minimum 40-50m2 area on South West facing roof with absolutely no shade whatsoever other than the log burner flue.

I am based in Fife, Scotland.

40m2+ ....... now we're talking  

Tonnes of potential then. Bad news, the bigger the system, the higher the cost. But the good news is that the cost doesn't scale up with size, so not as bad as you'd think. And for a bungalow, you should avoid scaffolding costs, which for many, can be more than the cost of the PV panels (which are pretty cheap these days).

So, off the top of my head, and Screwdriva can advise, but testing to the extreme, 10kWp may be ~£7k installed, if no scaffolding needed?

Of course, that may be more than makes sense, and will depend on what your DNO (district network operator) will allow in maximum inverter size. It's just to give an example of going BIG.

For a very good generation estimate, try playing with PVGIS a tool we all use on here. Don't be intimidated, just stick a pin on your house and enter the approx roof pitch and orientation. Orientation uses south as the azimuth (point of interest), so SW would be +45, SE would be -45, south would be zero.

I popped a random pin in Fife, and left everything alone, other than 30d pitch for roof (I'm assuming as a bungalow it's shallow pitch, but of course could be steeper if rooms upstairs), and I entered +45 for azimuth. I left everything else alone (even system size, which I left at 1kWp default).

I got this result, suggesting 882kWh per kilowatt of PV installed, which is perfectly decent, especially if you have no shade.