Solar Panels UK - is it worth it?

[yessuz]

By the way, since we are talking here ..

What is the best way to set battery charge/discharge schedules in order to accommodate the IO or at least 6 hr fixed period with cheap power?

I will want to avoid car charging off the battery

 

[RedMod3]

By the way, since we are talking here ..

What is the best way to set battery charge/discharge schedules in order to accommodate the IO or at least 6 hr fixed period with cheap power?

I will want to avoid car charging off the battery

Again tonight I will set:

Charge limit to 80% in Car and Octopus IO App
Start Time to 23:45 in Car
Ready by 05:30 in Octopus App

This seems to give a burst charge at 23:45 and then IO charges at random times.

 

[yessuz]

Again tonight I will set:

Charge limit to 80% in Car and Octopus IO App
Start Time to 23:45 in Car
Ready by 05:30 in Octopus App

This seems to give a burst charge at 23:45 and then IO charges at random times.

OK...

and what about battery?

 

[RedMod3]

OK...

and what about battery?

The Tesla PowerWalls do not discharge between 23:30 to 05:30 unless you either select no Grid Charging or you go self powered. Mine are set for Time based control and if I have excess in the battery, I select no Grid Charging. However, When I have excess in the battery, that would only be after I've charged the cars from solar. I have not tried Time based control with no grid charging which charging the car batteries.

 

[Js1977]

OK...

and what about battery?

Is your car charger on its own consumer unit ? if so, when you install its just a case of not having this circuit backed up by battery, If not, ask your installer. This is the simplest way.

 

[yessuz]

Is your car charger on its own consumer unit ? if so, when you install its just a case of not having this circuit backed up by battery, If not, ask your installer. This is the simplest way.

aha! yes,
there is a split, straight at the meter. Car charger is not fed into main consumer unit and it has it's own breaker.

will check with installers anyway, but I tend to overthink some things and worry well in advance

 

[WannabeOwner]

I tend to overthink some things and worry well in advance

Well in that case ...

Wiring for excess PV to car charger if car charger is on separate circuit?

 

[yessuz]

Well in that case ...

Wiring for excess PV to car charger if car charger is on separate circuit?

welp, I will check with installed anyway. my consumer unit is in the middle of the house but completely opposite side from the meter box. car charger is on another side - so the location of those three points looks like triangle..

 

[phil4]

welp, I will check with installed anyway. my consumer unit is in the middle of the house but completely opposite side from the meter box. car charger is on another side - so the location of those three points looks like triangle..

I've a different setup sort of to you, but similar in that things are seperated. incoming mains and consumer unit under the stairs in the middle of the house and batteries (due to be installed) and car charger in the garage adjoining.
They ran 6 cables up under the stairs to the landing, round the corner and into the airing cupboard, up inside there to the loft, across that down through the eaves, and into the garage roof, down that wall and across the garage.

Zappi has wireless CT clamps (well the harvi is the wireless bit) so it can read the house and solar production, and so can charge the car only when excess being exported.

 

[yessuz]

I've a different setup sort of to you, but similar in that things are seperated. incoming mains and consumer unit under the stairs in the middle of the house and batteries (due to be installed) and car charger in the garage adjoining.
They ran 6 cables up under the stairs to the landing, round the corner and into the airing cupboard, up inside there to the loft, across that down through the eaves, and into the garage roof, down that wall and across the garage.

Zappi has wireless CT clamps (well the harvi is the wireless bit) so it can read the house and solar production, and so can charge the car only when excess being exported.

my charger is Pod Point.

my batteries and inverter will be in the loft,..

anyhow, will have to think about it some way

 

[HenryT]

I approached the car 'charging from the battery' problem this way;

I set the battery charging time on the inverter to 00.00 to 05.30 - it seems that with my setup that if the battery is in the charging period it won't discharge (logically, I guess). I use 00.00 instead of 23.30 as the start time just to spread things out a little.

When I charge the car I set the departure time as 05.30 on the Octopus app so the car charging will stop at that point regardless. If I didn't do that, the car would then charge (in part) from the house battery, despite extra cheap electricity potentially being available to a later departure time when needed.

Moral arguments aside, I could 'game it' and change the battery charging period to align with the car charging schedule Octopus supply when it's beyond 05.30, but it's too much of a faff doing that each time for a few pence, plus the inverter is in the garage anyway and my inverter app isn't that sophisticated to do it remotely.

 

[phil4]

my charger is Pod Point.

my batteries and inverter will be in the loft,..

anyhow, will have to think about it some way

My inverter is also in the loft.

As discussed by others you either need to tell the inverter not to discharge, or get the pod point monitoring things. No idea how you'll charge "with solar" though, as you'd defo need some CT clamps to the pod point to do that.

As an example as to why you might want that, yesterday, despite numerous clouds and rain, the car got a 12% boost in charge. If I'd left the charger running normally, I'd have been in for a fair old bill, but because the zappi stopped or reduced charge as needed, it cost next to nothing.

 

[RedMod3]

My charger is on non-backup. I tend to charge the car when I have excess solar, but when the solar excess is less than the car charging current that I have set, the extra needed for the car comes from the battery. I don't mind this as we rarely have a completely blue sky, so as long as the average solar is greater than the charging current, the battery gets more added to it than gets drained.

Currently my PWs are at 88% with 1.7kW surplus, when I hit 93%, I'll start charging the car at 6A initially.

 

[ACarneiro]

Moral arguments aside, I could 'game it' and change the battery charging period to align with the car charging schedule Octopus supply when it's beyond 05.30

I tend to be somewhat critical of people gaming the system by artificially reducing the charger rate in order to get longer "off peak" periods, but what you have described seems to be specifically allowed by the IO T&Cs. They specifically state, and in fact make it a selling point, that you're allowed to have all your house loads at cheap rate.
I agree that it's probably not worth the faff and I wish IO would integrate with the Powerwall system but I don't see that as "gaming it" at all.

 

[daveface]

I normally just leave my battery to charge between the standard IO hours of 23:30-05:30. Then let IO schedule the car in for when ever it wants. Most of the time it will start its charge at around 23:00. I then end up charging the car / battery and turning the washing on etc... all at the same time in the low rate period. My battery along with my solar will provide all the power my house needs during the day

 

[PITA]

I approached the car 'charging from the battery' problem this way...

I approached the car 'charging from battery' problem by installing an additional car charger wired in directly after the electric meter.

This way, the home batteries cannot see it... and the draw is only ever Grid Use when using this charger.

This keeps it all well away from the house use, Powerwalls & Solar Excess.

Intelligent Octopus can do what it likes, at any time when using this charger.

 

[PITA]

... then we have an original 7kW Zappi wired into the Tesla Gateway 2 which can charge directly from the Powerwalls & Solar Excess at the full 7kW.

So I never worry about the solar-excess 1.4kW minimum limit. Just plug into the car in FAST mode and set how much I need.

This works great as well.

 

[yessuz]

I approached the car 'charging from battery' problem by installing an additional car charger wired in directly after the electric meter.

This way, the home batteries cannot see it... and the draw is only ever Grid Use when using this charger.

This keeps it all well away from the house use, Powerwalls & Solar Excess.

Intelligent Octopus can do what it likes, at any time when using this charger.

ah, so that is my set up at the moment - my charger is wired straight after the meter.

what I can do in cases when I will have excess power - I will be able to use mobile charger with granny to drip in some solar electrons

think this is, at the moment, the right approach.
I may think (if possible) to set up commando in garage or outside and use that one if I will have lots and lots of power...

 

[PITA]

ah, so that is my set up at the moment - my charger is wired straight after the meter.

what I can do in cases when I will have excess power - I will be able to use mobile charger with granny to drip in some solar electrons

think this is, at the moment, the right approach.
I may think (if possible) to set up commando in garage or outside and use that one if I will have lots and lots of power...

Yep, this is our exact setup...

1 x 7kW Zappi wired into Tesla Gateway 2 on Grid-Tied side

2 x 22kW Zappi wired into 3 Phase Distribution Board.

So if we then have a powercut, none of the above chargers work. They're all grid-tied.

But... I then have a 32Amp Commando Socket wired into the Tesla Gateway 2 on the Backup side.

So I can selectively use the Tesla Universal Mobile Charger if I want or need to... straight from the Powerwall Batteries.

The reason I've done this is to protect these 'Smart chargers' during a Grid Blackout from accidentally draining the Powerwalls or stalling if they ever require an Internet Connection to operate.

Even though we failover now to SpaceX Starlink

 

[yessuz]

Yep, this is our exact setup...

1 x 7kW Zappi wired into Tesla Gateway 2 on Grid-Tied side

2 x 22kW Zappi wired into 3 Phase Distribution Board.

So if we then have a powercut, none of the above chargers work. They're all grid-tied.

But... I then have a 32Amp Commando Socket wired into the Tesla Gateway 2 on the Backup side.

So I can selectively use the Tesla Universal Mobile Charger if I want or need to... straight from the Powerwall Batteries.

The reason I've done this is to protect these 'Smart chargers' during a Grid Blackout from accidentally draining the Powerwalls or stalling if they ever require an Internet Connection to operate.

Even though we failover now to SpaceX Starlink

you are in midlands, but sounds like you are located in outbacks