Solar panels and battery - any real world reccomendations?

[GinG]

Morning all,

I've started to look at the mind field that is Solar and wondering if anyone can offer real world reccomendations?

I've got virtual consultations booked for today and tomorrow with another company coming to see me on Tuesday.

I've got people offering GivEnergy systems, another which have a few more offerings including Huawei, FoxESS with modular battery setup and then Lux power.

Budget I have been told is quite healthy at between £8-£10k.

Companies are obviously going to say their products are the best on the market and that's why they are using them,

Any reccomendations will be greatly appreciated.

 

[GinG]

Haggle. A lot. When we got panels fitted it was crazy how much wriggle room the companies had. Even the company that said they charge a bit more because they're awesome etc, came back with a much better offer after we told them we're going elsewhere.

What sort of savings did you see?

 

[GinG]

I think between the starting point and the price we paid (and I suspect we could have got lower), over £1k (though this wasn't just one company, it was several with comparable systems), we paid about £4.5k I think (memory might not be spot on), and I'm sure we could have got it at least a couple of hundred lower.

Interesting...I'm looking at a 6Kw system with battery.

May see what they come back, prices all seem to be very similar so I guess it's whoever is hungry.

Everyone is busy with enquiries....I just wonder how many people are actually going to pull the trigger.

 

[GinG]

Im getting 14x Trina Vertex 390w panels, Givenergy 8.2kw AC coupled Battery and a solis 6kwh inverter installed on the 8th Feb, I plan to add a second 8.2 or 11.3kwh battery and the 2nd gen GE inverter charger Q3-Q4 this year as it increases the charge & discharge rate to 5kwh
If you can find them, from what I have read online the new Panasonic Evervolt panels are the best on the market ATM, they lose less efficiency to heat than any other residential panels on the market. (NOCT and temp coefficient figures).
Most panels ratings are with the panel at 20 degrees, but on a 20 deg ambient temp they will be around 45 deg, the pannys seem to retain their efficiency at higher temps, and from what I have read their 360w panel will out perform my 390 as they heat up, but I cant find any stock in the UK to even see how much of a price difference there would be

Thanks for that. I had a company ring today and all they offer is the Tesla Powerwall so I politely told them that it uses up most of my budget so thanks but no thanks.

Is there any reason why you aren't going to just install the batteries all at once? You will only pay 5% vat on installation with the solar but then pay full Vat if you then install more at a later date.

 

[GinG]

So...had a quote today well within budget.

Question is on a usage of around 12-15kwh per day would you go 5.2kwh or 8kwh battery?

Price is around £800 difference.

Based on the company savings calculator I'd only save an additional £20ish per year and consume 77% Vs 73% of the electric generated.

The calculation however doesn't take into consideration being able to charge the battery overnight on a cheaper tarriff. I'm wondering if I'd benefit in the longer term and the savings would actually be greater over the winter months?

 

[GinG]

What's the overnight tariff compared to the day one? Then just work it out from there.

Currently paying £0.05 but will be going up to £0.075 so compared to £0.15 or potentially £0.35 in September for day rate, the cost difference is quite significant.

 

[GinG]

Being conservative at an extra 2kwh a day then, you're saving 27p a unit, so 54p a day. Over a year that's getting on for £200, seems pretty smart to me, pays off in 4 years.

EDIT - Of course, during the summer, when you're generating a lot, then it's not so good if you manage to use most of it. Equally, if you can't use your own generation, then it's an even faster payoff time.

Thanks for that.

I think I will go for the larger battery...I have also asked them to pride me for 2x5.2kwh batteries as a comparison.

So far price is £9522 for 6,370kwh system, 5kwh GivEnergy inverter and 8.2kwh battery.

£8755 with a 5.2kwh battery.

 

[GinG]

I’d want enough battery storage to be able to provide for the the house all day.

I’ve had solar since 2011 and added a Tesla PW2 in November.

I’m on 5p octopus go, the average unit price I’ve been paying is just over 6p since installation.

For comparison I'm paying £0.08 by shifting most of our usage overnight...this is without solar.!

 

[GinG]

Where are you in the country ging? Think always helps a bit for comparisons.

North Yorkshire

 

[GinG]

That isn't a bad price at all really. Who was the quote from? My friend lives in Hull and is looking for an install similar to mine, but doesn't want to do it himself.

The GivEnergy system is great value for what it offers, it might be worth asking how much adding a second 8.2kWh pack would cost now, vs. having it done later if you are using a lot of energy. I chose to only buy one, and get another further down the line, but I am almost regretting not getting two done straight away some days, especially with low sun days, and obviously shorter winter days.

Company called Effective Home https://effectivehome.co.uk/

I have been really impressed with the contact so far, they get 4.6* on Trustpilot with over 700 reviews.

 

[GinG]

They wanted £3300 to install a second battery but I can buy it for £2500 and install it myself, seems simple, power connection to other battery and coms to the charger then a call to GE to configure it from their side. Plus the larger batteries are not available yet and I didnt want to wait as the prices will probably be higher by Q2 this year.
Tesla powerwall is nice as it has automatic failover to the battery, I can add this with the GE battery but the Automatic changeover switches are over £1000 so not worth it for where I live as the powercuts are usually minutes in length, I will use a manual changeover sw for circuits, lights and Aircon.

The one thing I would like to find how to do is find a way to allow Solar PV power generation during a powercut, as the inverters will shut down when the grid goes down to protect anyone working on the grid. Im sure there is way to configure a double pole switch that can ensure we are isolated and then feed 240v from the battery to the inverter allowing it to power up.. this would be great for situations like they had in Scotland recently with several days of power loss.

Makes complete sense doing it that way...I did also wonder how easy it is to add one yourself later down the line.

In relation to the solar PV during a powercut...is this what 'Islanding' does?

 

[GinG]

Just been quoted 23.2k for a 7.5Kwh system with a Tesla Powerwall Will get phoning around some more based on the above!

It's the Powerwall which ups the price loads and in the UK is a little overspec'd really...unless you have regular power cuts?

So most companies are saying I can only really fit a maximum or 14 panels at 390W but then I've had another company come back with 16x 455w.

With 5kw inverter and 8.2kw battery quotes are coming in at around £8200 - £8800 for just over 4kw in solar panels. £9800 ish for the 6kwh system.

Payback quotes are not dissimilar to the 4 or 6kwh systems so I am wondering if it's worth the extra solar panels due to the payback time...around £70-£100 per year is being quoted for avings with the bigger solar system which increases the payback period somewhat.

 

[GinG]

It may seem odd but as the 455w panels will be 2.11m x 1.05m panel (2.215m2) vs the smaller ~390w which will be 1.77mx 1.05m (1.86m2) so each panel of the 455w is 12% more surface area. You might have a very tall roof, meanings the large panels are somewhat a better fit as it wastes less roof space. Do you know the height and width of your roof sides?



The extra cost should only be panels, plus the uprated inverter costs. It is worth getting as many panels as possible installed as the vast majority of the cost is in the labour and scaffolding etc. Adding 2KW or for £1k based on your numbers makes total sense, that is 50% ore generation potential for an uplift of less than 15% costs. Same would apply to going to a relatively huge 7.2kW system, it it is adding a little on top but will allow you to generate more in the darker months, and export more in the summer months, then you'll soon pay the extra back. The only caveat is that with the much larger system you'd probably want to go with a dual/split inverter system 3kW each so you can charge the battery(ies) faster, and or a car at max rate if not wanting to export at low value, it's also worth exploring the dual 5.2kW battery cost vs a single 8.2kW, as you can then also discharge at 6kW if you want to run more items in your house at peak times from the pack(S)

Thanks for the info.

I'm not sure on the size of room unfortunately I can try and find out what the companies are basing the sizes on.

I see what you mean in regards the actual cost of panels Vs the generation.

I am finding that depending on the companies that they will say that they can only fit certain amounts of panels as that is what they only supply. The one company offering the biggest system is a large multinational energy system (supplies boilers etc) and offers a variety of brands and panels.

I've been advised a 5kw inverter is best with the 8.2. I have also asked for a price based on the 2x 5.2 batteries however not sure on the efficiency Vs the 8.2 which is the actual storage with it being a 10kw battery compared to the 5.2 which has a DOD of 90% I believe?

 

[GinG]

Yes, I think a lot of the time they have their own interests being put first, and selling what they make money on or have lots of in stock/easily available. I'd much rather wait for a fully bespoke system that just whacking up whatever they suggest, after all it is a very long term commitment you are making.

When I designed my system, I did it with a view of changing the panels after 10-12 years depending on how much the technology changes, so I chose panels that offered a good £/w/area, rather than Solar Edge/LG etc. as you were paying a for a warranty and a slightly higher % efficeincy loss over 25 years, it made no sense to spend up to 50% more for and extra 30w per panel. I'd imagine once they scale up making PV with perovskite panels we'll see cheap 550w+ panels and my energy use is only going one way once everything is electric in my home, so going from ~6kW to ~9kW will make a huge difference.



Check the stats on the two inverters, you'll see the are the same with 2600w max out put from the battery, but when using both solar+battery it changes, as the 3kW inverter only allows 3600w vs 5000w on the 5kW version, so if running 2x 3kW you get a max battery output of 5200w, or 7200w using both at once. Those figures are for the backup output.The DoD of 90% is standard now across all there batteries I believe, as they have gone with a 10 year or 26MWh warranty now, but I'd say they last at least 2x as long as that.

Thanks mate...once I get a couple of other quotes in would you mind if I sent you a trust message and get your opinion please?

 

[GinG]

Sure thing happy to cast a glance over them, I'm not an expert mind you, just a well informed novice.

That'll do for me!

 

[GinG]

Pretty much just had the same quote today c. £9k for 6kwh system system, 5kwh inverter and 8.2kwh battery givenergy too. coming round in a couple of weeks to give a formal price as that was just over the phone. @Journey would I be right to assume that going for another battery on top of this would be beneficial?

Currently use about 20-25kwh a day, but no electric car in the house, but plug in hybrid coming in May and as said earlier i'd ideally like to use the AC as my primary heat source. - All cooking is electric.

Who was that with out of interest?

I haven't gone back to any for any discounts as yet...£9k would be a sweet spot for me for that system.

 

[GinG]

Small Company just up the road from me solarpowerful.

Ah ok thanks, I think 9kish is a sensible cost for that sort of setup.

 

[GinG]

So I've been in contact with another company...this time much more local.

This guy however has made me slightly concerned about the DNO and costs involved?

He states there could be no charge, a charge of around £650+Vat or even more.

Our house is on a newish build estate built in 2016...what is the likely hood of having some obscene charges?

Would it be worth me obtaining quotes for a DNO compliant system? Under 3.68kw I believe?

 

[GinG]

I'd be inclined to just get the G99 application done with your DNO and they will tell you if anything needs to be done to enable a larger system, there isn't anyway the installer can tell you until the DNO does. I know someone who had to pay £3k but they lived in the middle of no where and had a huge install of 22kW.

Do you mean I just go through doing it now?

Is there any costs involved or does all this get put in as a no obligation quote?

 

[GinG]

I did mine with the DNO and got my electrician to complete his part of the form then send it in, once I had decided on the system size and a rough install date, total cost to me was nothing, and the wiring to my house was fine.

So you didn't even have to pay a penny?

I have just called my network operator and they advised me to send in an email to their generation team. Hopefully see if they can give me n idea on costs.