Solar options (mind field)

QrizB

Martyn1981 said:

Pretty silly to use a compounded 8% for fuel savings .. 

Agreed; that's the sort of crazy maths that you'd see from unregulated companies a decade ago. of energy prices increase by 5% above inflation for 25 years it would put the Ofgem cap at something like £6k pa in current terms by the end of that period. Electricity at £1 per kWh, in today's money.

Also assuming 15% export seems low, even with a battery. All these long summer days when you're generating 30kWh/day or more, and you won't be able to use them.

I'd suggest this company are cowboys, or at the very least their sales person has gone off-piste.

Is that projection editable? What do you get if you increase that 15% to 30, and reduce the 8% to 3% (to match inflation)?

I might chuck some numbers into Excel and recreate it later ...

phill2-0-0-3

QrizB said:

phill2-0-0-3 said:

These are the two quotes I have received the rear of my property has 3 seperate pitches.
I have enquired if I could have 4 panels on the rear and then the front done which is more cost efficient 
Does this seem a fair price ? 

Without getting into the details, Option 2 costs less, generates more electricity and pays back sooner. So it seems a much better deal than Option 1 is.

Also if the panels are facing northwest it means you'll get most of your output in the afternoon and evening, when electricity is (currently) more expensive.

If the only choice was those two options, I'd take Option 2.

Now for the details.

If you're using 7000 kWh/yr of electricity, that's an average of 20kWh/day. Where does it all go? Do you have electric heating, hopefully storage heaters and/or a heat pump?

If it doesn't include heating, your house will swallow a 5kWh battery and still be hungry for more. You might want double that, and could even think about a Powerwall 3. If you drop Screwdriva a DM he might know an installer in your area who could quote for one?

No electric heating.  
Minus occasional in the winter if we don't want to use the c/h
There's 6 people who live in the property. 
My other Children from a previous relationship come round but don't live here . 
We do use a lot of devices . 

I've received a new quote to produce 7500kwh
£10000+ 
I haven't heard of the power wall device I will look into this . 

Many thanks 

phill2-0-0-3

Here's the information on the panels 
Are they any good ? Thanks 

QrizB

Aiko are one of the cheap n cheerful Chinese manufacturers. They ship a huge number of panels (Bloomberg has them joint 11th largest in the world).

Your installer's website makes a bit of a thing of how they fit Sharp solar panels. Wonder why they're quoting Aiko for you?

https://ups-solar.co.uk/products/

Screwdriva

Martyn1981 said:

I actually think north roofs are worth considering, at least briefly. But crucially they need to be in addition to a south roof install, as at that point the extra cost could be 50%/kWp of the other install, making up for the lower generation. But even then there are caveats these days, that didn't apply just a few years ago, such as cheap panels being used for fences, maybe a carport, pergola, or even wall mounted, as this is now PD*. Those options if better sited than a northern aspect roof, might fair better, especially again if batts are used. Times they are a changing ....

This is where roof slope comes into play more than we may realize. On North/ NE/ NW facing aspects, the steeper the slope, the poorer the performance. On a 30 degree roof, you may eventually see a return on investment but on steeper inclines, performance drops significantly. At £200+ per panel, I recommend installing panels facing between 45 degrees and 315 degrees on a compass.

phill2-0-0-3 said:

I've received a new quote to produce 7500kwh
£10000+ 
I haven't heard of the power wall device I will look into this . 

I've seen everything I need to see - a typical cowboy trying to sell cheap Chinese kit at premium prices, which sadly is the norm these days. 

Installers I use to help other forum members offer 12 X 500W Eurener bifacial panels with the Tesla PW3 for £11K installed. If you can fit more panels on the S/W/E aspect, they charge £250 per additional panel.  

phill2-0-0-3

Screwdriva said:

Martyn1981 said:

I actually think north roofs are worth considering, at least briefly. But crucially they need to be in addition to a south roof install, as at that point the extra cost could be 50%/kWp of the other install, making up for the lower generation. But even then there are caveats these days, that didn't apply just a few years ago, such as cheap panels being used for fences, maybe a carport, pergola, or even wall mounted, as this is now PD*. Those options if better sited than a northern aspect roof, might fair better, especially again if batts are used. Times they are a changing ....

This is where roof slope comes into play more than we may realize. On North/ NE/ NW facing aspects, the steeper the slope, the poorer the performance. On a 30 degree roof, you may eventually see a return on investment but on steeper inclines, performance drops significantly. At £200+ per panel, I recommend installing panels facing between 45 degrees and 315 degrees on a compass.

phill2-0-0-3 said:

I've received a new quote to produce 7500kwh
£10000+ 
I haven't heard of the power wall device I will look into this . 

I've seen everything I need to see - a typical cowboy trying to sell cheap Chinese kit at premium prices, which sadly is the norm these days. 

Installers I use to help other forum members offer 12 X 500W Eurener bifacial panels with the Tesla PW3 for £11K installed. If you can fit more panels on the S/W/E aspect, they charge £250 per additional panel.  

What installers do you use ? 
Would it be possible to get the details ? 
Thanks 

Screwdriva

phill2-0-0-3 said:

What installers do you use ? 
Would it be possible to get the details ? 
Thanks 

Feel free to DM me - will do my best to help. 

QrizB

OK, I think I've modelled their proposal without their crazy inflation increases - so everything is in today's money.

Here's what I get:

It's a 25-year real return of 4%, which isn't terrible and is better than you'll get with an ISA or gilts. But that assumes that the system continues to work for 25 years without any downtime or (costed) replacement parts.

[That IRR might be slightly off; checking is vs. a compound interest calculator, it should be more like 4.05% but it's close enough.]

handful

Not sure whether I should be hijacking this thread or starting my own but I've just had a quote for a 10 panel system as follows:-

Solar Panels

Astronergy - CHINT Solar

4.500 kW Total Solar Power

10 x 450 Watt Panels (CHSM54RNs(DG)(BLH)/F-BH-450)

4,032 kWh per year

SOLAX X1-HYBRID G4

3.68kW of Inverter Power

SolaX Power  1 x X1-HYBRID-3.7-D

Specs

Battery

SolaX Power

5.3 kWh Total Battery Storage

1 x T-BAT LD53

I was very impressed with the rep and the company have extensive experience, don't subcontract anything and also do some installations for Octopus. They have a LOT of 5 star reviews on Google and Trustpilot. Rather than advise the cost in the quote, can I ask for some guidance as to roughly what this "should" cost and the quality of the provided materials? We have a bungalow with plenty of S/SW facing roof space but we are not huge users, hence the modest installation. The quote I have is taylored to our usage with payback etc all specified. Thanks in advance!

QrizB

handful said:

... can I ask for some guidance as to roughly what this "should" cost and the quality of the provided materials?

The solar PV (without the battery) should be under £5k, in my opinion, assuming easy access to your roof (it's a bungalow after all). The battery retails for about £1600 on top of that.

So less than £7k all told?

As for quality, it's mass-market kit. Nothing special, but likely to last to the end of its warranty.