Solar panels and battery - any real world reccomendations?

[Journey]

I'm struggling to see how I'd get to 'too much' energy....!

Hah, I know what you mean, with usage like yours even more so. Our heat pump will hopefully be installed before the year is over, but I'm not holding my breath as things got complicated, and I can't be bothered with the stress so I am not pushing it.
We have a BEV as well but only a tiny 38kWh battery in it so it is easy to fill, the new one (when it is out) will have 55-77kWh, and I'll be using the V2L on that as a total home battery via my new Victron inverter/charge controller/solar setup so that I never have to draw from the grid at peak prices. Both of these things mean no more gas bill, and not worrying too much about having the "spare energy" to cope with cold dark days.

 

[HungryHippos]

I can't see a good way of getting my home off gas supply really, I have a combi boiler and all it does is hot water/central heating, but I haven't really got a good place to put a large tank for a heat pump, and I think heat pump tech needs to come down in price (it's expensive even with the grants provided).

Ideally whatever I'd put in it's place would work with existing CH system and hot water replacement without a huge expense. Ideally just having the whole system more or less installed into the same cupboard in the kitchen as the current combi

 

[katie279]

I can't see a good way of getting my home off gas supply really, I have a combi boiler and all it does is hot water/central heating, but I haven't really got a good place to put a large tank for a heat pump, and I think heat pump tech needs to come down in price (it's expensive even with the grants provided).

Ideally whatever I'd put in it's place would work with existing CH system and hot water replacement without a huge expense. Ideally just having the whole system more or less installed into the same cupboard in the kitchen as the current combi

Hmm, tricky if you haven't got space outside - there's high temp heat pumps coming next spring that'll be a straight swap for gas (ie none of the low temperature stuff, masses of insulation required etc).

Only thing I can think is electric heating/underfloor? Expensive normally, but at 7.5p/kw with a battery, it might become an option? Basically charge batteries during the night for very cheap and then discharge to heat the house when you need it

 

[Ron-ski]

@katie279 With your usage and two EV's 3.6kw from the batteries is going to be very limiting. I'm going 8kw, mainly for the future, been meaning to change to an induction hob for a long time, just going to buy the cable and run that it whilst I'm doing the SWA. Haven't considered ASHP yet, if or when we do that will be another large cable to squeeze in, but I could pontentially power that from the garage.

 

[katie279]

Yeah good advice - I've emailed to see if they can get another inverter on order.

Does this change the install dramatically? Ie could I ask him to install the first one tomorrow and then retrofit the second once arrived?

I'm not sure if it'll need to be a complete set of extra wires from the solar panels or if you can daisy chain the two inverters?

 

[Balwant]

Yeah good advice - I've emailed to see if they can get another inverter on order.

Does this change the install dramatically? Ie could I ask him to install the first one tomorrow and then retrofit the second once arrived?

I'm not sure if it'll need to be a complete set of extra wires from the solar panels or if you can daisy chain the two inverters?

Straight forward, would use the existing wires coming down from the solar panels and then split between the inverters. Not sure if the connectors between battteries differ from the battery to inverter. They just need to make sure enough space is left for the second inverter and slack in the PV cables.

Would need extra cable from second inverter to the consumer unit and additional ac/dc isolators too.

 

[katie279]

Cool, ok so sounds like I should tell them to crack on with the single inverter and install the second when they have in stock (rather than delay!)

 

[katie279]

Ok, they've come back saying you can't have multiple inverters with the hybrid version.

Seems to reflect what Givenergy say on their site:

GivEnergy FAQS | GivEnergy

Question about GivEnergy products? We've provided handy answers to some of our FAQ in this webpage. Or, you can contact us for extra help.

www.givenergy.co.uk

Can I have more than one battery / inverter?
You can have up to 5 batteries per inverter. If you wish to increase the output power to the property, you can use multiple AC Coupled inverters with batteries connected to each. We do not recommend this for Hybrid inverters currently.

So the only Givenergy ones I can see are the 3.0 kwh ones - which mean two of them probably won't give me a huge uplift (ie 6kw vs 5kw/3.6kw)

Can anyone make any sense of this and/or recommend best way forward?

I'm not sure if there's better inverters out there? I'm not even sure what the 'hybrid' actually means??

 

[katie279]

In fact @Balwant - how are you getting 2 x 3.6kw inverters installed if the manufacturer doesn't recommend it?? Have I misunderstood something?

 

[Mercenary Keyboard Warrior]

Ok, they've come back saying you can't have multiple inverters with the hybrid version.

Seems to reflect what Givenergy say on their site:

GivEnergy FAQS | GivEnergy

Question about GivEnergy products? We've provided handy answers to some of our FAQ in this webpage. Or, you can contact us for extra help.

www.givenergy.co.uk

Can I have more than one battery / inverter?
You can have up to 5 batteries per inverter. If you wish to increase the output power to the property, you can use multiple AC Coupled inverters with batteries connected to each. We do not recommend this for Hybrid inverters currently.

So the only Givenergy ones I can see are the 3.0 kwh ones - which mean two of them probably won't give me a huge uplift (ie 6kw vs 5kw/3.6kw)

Can anyone make any sense of this and/or recommend best way forward?

I'm not sure if there's better inverters out there? I'm not even sure what the 'hybrid' actually means??

My understanding is the hybrid are switching in effect from multiple sources (panels, batteries and grid) and/or to multiple demands (house/batteries/grid), where as "normal" inverters just do one role
The problem with multiple hybrids from what I have read is that they need to be smart, otherwise they will see current from eg another battery inverter and decide to charge when you want them to output etc.

I think there are some issues with givenergy batteries on other inverters, not everything is compatible.

 

[katie279]

Hmm, I'm leaning towards just getting the 5kw hybrid and upgrading when a better one comes out.... remember I did that with my GeForce 970 though and 10 upgrades later....

 

[HungryHippos]

Hmm, tricky if you haven't got space outside - there's high temp heat pumps coming next spring that'll be a straight swap for gas (ie none of the low temperature stuff, masses of insulation required etc).

Only thing I can think is electric heating/underfloor? Expensive normally, but at 7.5p/kw with a battery, it might become an option? Basically charge batteries during the night for very cheap and then discharge to heat the house when you need it

Problem for the future I think.

In theory I could heat my house entirely on electric (I have a few indoor AC units that can do it relatively efficiently) but I dislike cold showers a lot so can't replace hot water needs yet!

The Octopus GO thing is a whole different kettle of fish entirely really, I am looking to switch to Agile Import/Outgoing instead because GO requires an EV which I don't presently have, Agile Outgoing pays pretty well when prices are higher for excess generation, though I don't anticipate I'll generate a lot of export units.

 

[Balwant]

Katie, Givenergy currently don’t officially support systems with dual hybrid inverters, however a number of people do already have this setup. For some it’s running absolutely fine, for others there can be minor niggles but nothing substantial. It’s basically seen as 2 separate systems and as result one can negatively impact the other along the lines of one battery discharging into the other but there are workarounds to limit this. Givenergy have announced that they are due to release hardware by the end of the year that makes dual hybrid inverters play nicely with each other and act as a single system.

 

[SoliD]

Definitely will consider getting a second inverter in a year when things calm down if that's the case @Balwant. Suspect should be an easy install as both strings go into current inverter As do batteries, should help with overnight charging as I've got the gen1 inverter so would only be able to charge 10.6kwh in a 4 hour window.

 

[katie279]

Katie, Givenergy currently don’t officially support systems with dual hybrid inverters, however a number of people do already have this setup. For some it’s running absolutely fine, for others there can be minor niggles but nothing substantial. It’s basically seen as 2 separate systems and as result one can negatively impact the other along the lines of one battery discharging into the other but there are workarounds to limit this. Givenergy have announced that they are due to release hardware by the end of the year that makes dual hybrid inverters play nicely with each other and act as a single system.

I love this forum!

Brilliant to know! That makes things so much easier, will stick with what I've got then and install the second inverter and this magical hardware later this year!

 

[katie279]

PS I've decided I'm going to install some RGB LEDs around my new solar batteries. You overclockers boys are letting the side down, so you're gonna get shown up by a girl....

 

[Journey]

PS I've decided I'm going to install some RGB LEDs around my new solar batteries. You overclockers boys are letting the side down, so you're gonna get shown up by a girl....

Rumor has it that you are not a girl, but actually a female looking Terminator.

 

[katie279]

Heheh, got that being one of the only five girls on my electrical engineering degree vs 450 boys!

Actually, I did love Battlestar Galactica - maybe a cylon effect would be cool on them..... !

 

[casper_uk]

Ok, they've come back saying you can't have multiple inverters with the hybrid version.

Seems to reflect what Givenergy say on their site:

GivEnergy FAQS | GivEnergy

Question about GivEnergy products? We've provided handy answers to some of our FAQ in this webpage. Or, you can contact us for extra help.

www.givenergy.co.uk

Can I have more than one battery / inverter?
You can have up to 5 batteries per inverter. If you wish to increase the output power to the property, you can use multiple AC Coupled inverters with batteries connected to each. We do not recommend this for Hybrid inverters currently.

So the only Givenergy ones I can see are the 3.0 kwh ones - which mean two of them probably won't give me a huge uplift (ie 6kw vs 5kw/3.6kw)

Can anyone make any sense of this and/or recommend best way forward?

I'm not sure if there's better inverters out there? I'm not even sure what the 'hybrid' actually means??

A decent video here which helps explain a few terms and how they work:

Hybrid Inverter vs AC coupled home storage solar battery

Hybrid vs AC coupled. (Updated to correct misleading information) Having tested the AC Coupled Givenergy battery 5.2kwh we've now installed the new Huawei Su...

www.youtube.com

 

[SBo]

Going back to tariffs, after a profitable summer and with the days starting to noticeably shorten I am about to switch from Octopus Agile and Agile Outgoing to GO and their standard feed-in tariff.

However, I note that export prices are frequently 60p+ at the moment and perhaps will rise even higher in winter. My import is capped at 35p for the time being.

Would I be crazy to stay on my Agile combo, charge my 10kwh each day at 35p (less solar input) and discharge at peak hours for a seemingly reliable 30-50p profit per kwh and then have covered the cost of the 10kwh of daily use I need. Could work out better value than GO?