Solar panel install, is this a good price for Manchester ?

MancMan123

Afternoon all.

I fear that I am late to the party .................. but at least I have made the decision to go to the party, and not just listen to it from outside :-) 

Due to what is going on with electricity prices at the moment and where I think they may go in the future, my wife and I are discussing getting panels and a battery.

But can I ask the people who know a lot more about this than me if the following is a good price/setup?

1st a bit about our house, we live in a detached property with a 40m2 roof that I think is around 25 degree slope, we don't really have much shading and face due south.

We are 2 adults who work from home and our yearly use is 3400kw/h ............ we have GCH and a combi boiler (no hot water tank or electric car)

I thought getting quotes would be easy, but who knew the companies are mad busy at the moment.

The quote we have been given is as follows 
14 x SHARP All Black Solar Panel 400W Per Panel Solax X1 Boost
£7340

I can add the following battery ........................ I intend to get a battery so that during the winter I can top them up at night on a "Cheap" rate

Fox ESS Hybrid & 5.8kWh Lithium Ion Battery

£3080

Total £10,400

Thank you for any advice given

Screwdriva

You're lucky you have an unshaded south facing roof. That said, I don't believe that's a fair quote at all. I've just seen my installer quote today for another forum user:

10 X 400W Sharp Black panels
10 X SolarEdge Optimizers
  1 X SolarEdge HD Inverter 

25 year warranty on all of the above. £5750 installed. 

Given how much Octopus is paying its outgoing agile tariff (today is particularly lucrative), it may make more financial sense to use the grid as your "battery" and export instead of store (unless you're a heavy after dark user) for the next couple of years or till prices drop down to single digits (a big if). Waiting isn't a bad thing - battery tech is the only component that is dramatically improving each year and there is an ethical argument in favour of that Lithium ending up in a car (vs. a home).

Alnat1

Did the quote mention and include getting DNO approval for the larger installation? Was this discussed and you were happy to be limited to 3.68kWh output or did they not bother to tell you about it?

MancMan123

Thanks for the comments above.
I have emailed them about the use of optimisers and whether or not I should have them. But more importantly about the need for DNO registration.
As it was them who came up with the power output size one would hope they have factored it in.
Thank you

As for the battery, this is to supplement our use in the winter months when the solar is going to be down to very little, and we can get cheap(er) electricity at night to refill them

(also my fridge freezer seems to use a lot of power at night time :-(     )

Alnat1

Battery also works well when it's filled up after a decent day but it's dark before you cook dinner 

MancMan123

I spoke to the firm this afternoon, and the quote he gve me was without optimisers (£50 each if needed) he did however sayu the panels they are installing are effectively split top and bottom. meaning if the bottom part is in shade then the top half will out put as normal, in essence acting as inbuilt optimisers.
Re the panel size of 5.6 kwp he said the output from the inverter is limited to 3.6 to meet regualations, I asked where does the other 1 or 2 kw/h battery go, does that overspill into my batteries ........... he is getting back to me with that answer.

As for my quote, that does include £500 for scaffolding.

As always, thank you for any guidance given (i did not know about DNO etc)

Martyn1981

Hiya MancMan, just a thought, but 40m2 roof is pretty big, so good news. I'm just scribbling estimates on a scrap of paper, and trying to guesstimate panel sizes, and space needed around the edges, but perhaps 18 panels might fit?

But why, I hear you ask. Well, you are actually low users, despite both working from home, but I wonder if you're considering get a BEV in the future, since you'd be able to charge it off solar during the day, for half the year, so you could address both your leccy import, and fuel consumption too, if you are car owners. You might also benefit from installing a modern aircon unit, as you'd be able to run it as a heat pump during the shoulder months (warmer heating months) from a bigger PV system. You may find it could replace much to most of your heating needs in Mch to May and Sep to Oct.

It's always best to go as big as possible (within reason) with PV, at the start, since there are a lot of fixed costs, so adding more later is expensive, but a few extra panels don't add a lot to an install. Your installer can ask the DNO for prior approval for a higher export limit, which I think you need to do anyway.

Regarding DNO and 3.68kW export limit. In the UK, it's worth taking our not so great weather into account, so undersizing an inverter by 10-20% may actually make sense, since it runs more efficiently at lower levels, and the UK sees a lot of 'lower level' weather.* But, 5.6kWp (14x400Wp) is oversized for a 3.68kW inverter. They can fit one big enough to cope, and cap it to 3.68kW, that's not a problem, but it'll waste a lot, especially for your roof.*

So if you apply for a larger limit, say ~5kW, for the 5.6kWp array, then you might as well consider trying for 6kW for ~7kWp (18 panels). Just a thought.

*Your roof will be particularly wasteful for a 3.68kW cap, as at just 25d pitch, a shallow angle, it'll be a summer specialist, generating the most when the sun is highest (May - Aug). I did wonder, given the pitch if it was a bungalow, but you say scaffolding is included? [Edit - Sorry, my silly wording, of course your system will generate most May to Aug, what I meant was that with a shallow pitch, the summer gen will be enhanced, and the winter gen reduced, hence why capping in your situation will be slightly greater. M.]

Apologies for throwing out more questions, not answers.

Alnat1

@MancMan123 I was in the same position as you when we had our system installed in March, knew a bit but realised after, not quite enough.

With hindsight, our 5.25 system caps quite a bit, especially on the sunny days under 25C. I didn't know about getting DNO approval for more than 3.68kW output and would have gone for it. Also, we got 4.8kW of batteries, I think that we really could have done with double that, enough to cover 24 hours use.

I definitely think installing solar was the right thing to do and I am enjoying learning more about it.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              

Mikeyboy01443

Just wondering why they arent adding a solax battery to the quote, seeing as they have quoted a solax inverter?
Perhaps due to stock issues?

Rolandtheroadie

Same kit as I've been quoted for in the past 2 weeks (Sony 400w panels and Fox 5.8KWH, no boost thingie), apart from I'm only 11 panels. Mines is £10k

 I'm 2k down on my original quote so happy with that, we're in Central Scotland.

 The surveyor brought up the DNO stuff and said they deal with it. 

ccbrowning

Contrary to everyone else, the price you've been quoted seems about normal for the northwest in my experience.