Could i get a view on a solar quote please?

horace972897

Hi, had a solar quote we're thinking for going for, can i get a sanity check on it please?

We use around 8500kwh per year - in all day - have recently bought an ev which we will be charging on a EV tariff and filling the batteries overnight on that tariff.

We also have quite a bit of shading from large tree's 10 metres away.

Quote details:

17 Aiko 475 panels

Sigen Battery 10 x 3 (27.12kwh total)

2 x Sigenstor EC 6 invertors

17 Module level PV Tigo Optimisers

All works scaffolding and DNO etc

Total cost is £14800

Does this sound reasonable?

Martyn1981

Wet finger in air, looks like a decent quote. Quite a package.

Got me thinking though, that's a big battery package (I have similar scale). So you should be able to run the house all day time higher rate, off the charged batts at presumably a nice cheap EV rate. So your PV will 'only' be saving you cheap rate / earning export rate (not displacing day rate leccy, in case you are told double savings (from batts and then again from PV)).

Not being negative, I'm an absolute massive fan of PV, it's just a recent development, that batts getting so cheap, are starting to offer an alternative to PV if you can charge them on cheap rate. Effectively, you can't save the 'big' money twice, which is replacing day rate leccy prices.

But anyone with a poor roof but the ability to get a decent cheap rate tariff, now has a pretty good batt only option.

Sorry for the digression and ponderings.

Back to your PV and batt plans, good luck, it's great fun, especially when you start driving on sunshine (or wind from night time charging).

Lastly, a side question I sometimes ask, do you have a heat pump? If not, have you been thinking about getting air conditioning after the last summer? Just to say that a modern A/C unit typically referred to as an A2A unit (air to air) can also heat. And even one unit (I heat my house with two) can make a big difference by pre-heating a house on cheap rate overnight, or even all day, if you have enough spare battery capacity. That means heating at about 1/3rd the cost of your cheap rate, and reducing gas consumption. You can argue (man maths?) that the heating device is a free side effect, if you want the A/C anyway. 😉

Screwdriva

https://forums.moneysavingexpert.com/discussion/6687366/could-i-get-a-view-on-a-solar-quote-please

It's rare that I disagree with @Martyn1981 but I do not believe this is a good quote for several reasons:

1) Sigenergy hasn't been reviewed well. Comments appear to highlight abysmal after sales support.

2) This pairs poorly when paired with unnecessary incremental points of failure in the above quote: 17 X Tigo Optimizers + 2 Inverters + 3 batteries.

3) For low to medium shading, panels with 3 bypass diodes should be more than sufficient.

4) Are you able to sympathetically trim the tree to reduce shading? An image of the shading would be helpful to judge.

horace972897

Thanks for the replies both.

To answer @Martyn1981 's questions:

No not currently looking at heat pump as not sure our 1970 radiator system would work well with it, but will be definitely looking at it if our boiler needs replacing.

We already do have A/C but that;s installed in the conservatory and in two mobile units - will look at those for heating / using excess solar when hot etc.

To answer @Screwdriva :

The problem I have is that I wish to control the solar / battery setup via home assistant and for this to work effectively the system needs to much more open than the Tesla ecosystem - currently my main choices are Fox ESS or Sigenenergy as i know they both work well with home assistant and predbatt etc.

Regarding reviews of sigenergy - it's also hard to get reviews of Tesla powerwall as they seem to be bundled in with reviews of their cars etc, and the reviews of Fox are pretty mixed as well. It's really hard to know who to go with.

Regarding shading, whilst one of the tree's that shades our roof is in our garden and possibly could be trimmed slightly, there are also three other similar sized trees that are in three different neighbours gardens and they are all under tree preservation orders which limit how much can be trimmed. If you can imagine the roof is south east facing and the tree line is parallel to the roof across an arc of around 10 metres - 15 metres from my roof (a lot of the canopy extends to nearly 5m away from my roof and they are much taller than our house). There is quite a lot of shading - the quotes have a shade factor of between 0.84 and 1 on them at the moment.

The quote listed above includes bird mesh

Screwdriva

Just to give you additional perspective on Tesla (having helped 50+ households with the PW3), you may be aware that they have recently discovered a fault with the previous generation of Powerwall. All affected units are being replaced by Tesla with the PW3 at no cost to the homeowner.

In my observation, it’s the only battery inverter with the cold weather performance, after sales support and capability combined into one unit.

debitcardmayhem

@horace972897 I believe there is an integration for HA and PW

edit: yes with limitations

https://www.home-assistant.io/integrations/powerwall/

horace972897

Hi @debitcardmayhem

You are correct there is an integration however it has limitations and only exposes data as far as i can tell and not control - however…………

A further review following your post has me finding Predbat (the software that does the prediction of solar, import of tariff info and control of charging and discharging) now listing Powerwall as a supported inverter using the Tesla Fleet API - so i will be doing a bit more of a deep dive into that before making my final decision - Thanks a lot much appreciate the nudge :)

Qyburn

Home Assistant can monitor and control Solaredge via Modbus, ie local control over your home network and not reliant on Internet or Solaredge cloud.

sabretoothtigger

Get more then one quote seems good. I mostly worry about the upkeep,if it works every day I think all that capacity fits the price. I prefer coverage to be good long term for when it might not work for whatever number of reasons.

Martyn1981

https://forums.moneysavingexpert.com/discussion/comment/82174602#Comment_82174602

Don't worry, I actually agree with you.

Bad wording on my account, I meant that the size of the package (PV and batts) looked like good value, not commenting on the specific kit. Which I can now see is a bit misleading. I was rushing to blather on about other stuff, hence the short opening para.

I don't know anything about Sigenergy, but I watch a lot of Youtube vids/channels on all things RE/EV/PV/storage etc, and have noticed, shall I say diplomatically, 'some concerns' about them.

NedS

@horace972897 Can I ask why two 6kW inverters? Don't Sigenergy do a 12kW inverter?