On-grid domestic battery storage

EVandPV

I think someone already mentioned it up-thread but there's also the general satisfaction of being nearly self sufficient and closer to 100% green that I'm quite looking forward to.

ASavvyBuyer

Zarch wrote: »

Using the excellent Agile app from OpenEnergyMonitor, using the data collected from my emonPi.

https://guide.openenergymonitor.org/applications/octopusagile/

It shows over the past month that my average import price on Agile is around 10p-11p per unit.



So as much as I'd love the geekyness of owning batteries, i'm struggling with the maths/justification again for them.

My budget would be around £2.5k, so maybe get 4.8kWh of Plyontech with inverter and installation for that?
https://thinkrenewables.co.uk/lux-ac-48kw-battery-storage-system

Say 4kWh usable on the Plyontech?
4kw x 10p = 40p saved per day x 365 days = £146

£2500 / £146 = 17 years.

This seems to confirm.
https://great-home.co.uk/solar-battery-calculator-likely-bill-savings/

But feel free to correct me if those figures are wrong.

Maybe I just need to sit tight and wait of the prices to fall some more? But they'd have to almost half to get under ten years ROI?

Seems like time of use tariffs, with cheaper pricing outside of Solar generation periods is making the battery justification even more difficult than if on a fixed tariff say around 14p per unit?

I'm wondering if the 'battery money' would be better invested in an EV or some other consumption device to make use of the cheaper pricing?

I'm on Octopus Go, with an average cost of about 8p/kWh for ALL electric we import. That makes the justification for a battery system not worth it. IMHO it is better to support a company providing RE electric, as the Co2 impact is currently less than buying a new battery system. Especially as at least parts of it would need replacing before a ROI was achieved.

What for us would be ideal is a V2H inverter/charger, (for under £1k) so that we can store and use electric from less than 30% of the EV battery, charged from PV or the 5p/kWh rate at night.

EVandPV

The Pylons arrived today but like I say, we won't get the ac controller fitted for a few weeks yet.
Am I ok to switch the batteries on briefly to check they're ok ?

Edit : Actually, after opening one of the boxes, the power switch was already at 'on' and the green light below the
switch is lit.
Is it ok to check the SOC by pressing the red button without them connected to anything and should they not be switched off when not connected ?

Solarchaser

Yeah no issues.

If you wire a plug up to the power connector you can plug in the sofar, and connect up the batteries to play with the settings.

Look on YouTube for Michael gaughan, he is actually who you speak to at think renewables, and has made a series of videos on how to set up the sofar etc.

But in short, if you want to check the batteries, switch on, then press red button, that lights it all up, when light beside button is flashing they are "live" and soc bars will be lit.... from memory I think they come half charged.

I would switch them off when you are done playing

EVandPV

Solarchaser wrote: »

Yeah no issues.

If you wire a plug up to the power connector you can plug in the sofar, and connect up the batteries to play with the settings.

Look on YouTube for Michael gaughan, he is actually who you speak to at think renewables, and has made a series of videos on how to set up the sofar etc.

But in short, if you want to check the batteries, switch on, then press red button, that lights it all up, when light beside button is flashing they are "live" and soc bars will be lit.... from memory I think they come half charged.

I would switch them off when you are done playing

Thanks for that.
Don't have the ac controller yet, it's the Lux 3K we're getting.
I've actually been emailing Michael at Think Renewables for some info.
He was saying they don't stock the Sofar anymore as they favour the Lux.
Given that the extended warranty brings the Sofar to about the same price as the Lux, I doubt many people will go for them now anyway.

Pressed the red button, green light next to red button is flashing but no SOC lights ??
Haven't unboxed the other one yet.

Edit : Took a meter reading from the terminals and got 49.2 volts.
Sounds about 60-70% from what I gather ??

1961Nick

EVandPV wrote: »

Thanks for that.
Don't have the ac controller yet, it's the Lux 3K we're getting.
I've actually been emailing Michael at Think Renewables for some info.
He was saying they don't stock the Sofar anymore as they favour the Lux.
Given that the extended warranty brings the Sofar to about the same price as the Lux, I doubt many people will go for them now anyway.

Pressed the red button, green light next to red button is flashing but no SOC lights ??
Haven't unboxed the other one yet.

Edit : Took a meter reading from the terminals and got 49.2 volts.
Sounds about 60-70% from what I gather ??

The SOC indicator doesn't work properly until the battery is connected to the controller & either charging or discharging.

joefizz

EVandPV wrote: »

Pressed the red button, green light next to red button is flashing but no SOC lights ??

Patience padawan, patience.

EVandPV

So I linked up the 2 batts as per the manual and on powering up the first batt, the second one also powered up and the SOC lights are now lit up.
The first batt is at 49.2v and the second is 49.7v.
The SOC lights on the first batt are flashing which I presume means it's charging from or balancing out against the second batt.
Is this normal and ok to leave them until they balance ?

Really appreciate all the help and advice here by the way guys. 👍

ASavvyBuyer

ASavvyBuyer wrote: »

I'm on Octopus Go, with an average cost of about 8p/kWh for ALL electric we import. That makes the justification for a battery system not worth it. IMHO it is better to support a company providing RE electric, as the Co2 impact is currently less than buying a new battery system. Especially as at least parts of it would need replacing before a ROI was achieved.

What for us would be ideal is a V2H inverter/charger, (for under £1k) so that we can store and use electric from less than 30% of the EV battery, charged from PV or the 5p/kWh rate at night.

Been looking again to see if there are any V2H inverter/chargers available now. Found this Quaser DC Charger, by Wallbox. Have asked for a quote.

EVandPV

ASavvyBuyer wrote: »

Been looking again to see if there are any V2H inverter/chargers available now. Found this Quaser DC Charger, by Wallbox. Have asked for a quote.

Interesting !
Strange that they went with chademo though when ccs is becoming the dominant connection.