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Discussion Starter · #1 ·
Looking for tips to beat use my limited solar generation. I don’t get paid for exports so I want to use as much as practical, but it’s only a 2.6kw array. I was getting around 1.6kwh today for a few hours, and my background usage is around 200w so barely enough for a minimal charge

on the zappi I think you can set a % for green so it’ll start charging at eg 1kwh solar and top up to 1.4 with the difference from the grid? If so, what’s a good balance point -50-60% green? Can you set that in the app or does it have to be on the unit?

I’ll be (soon) on octopus go so I should have plenty of overnight capacity to top off the car if needed so the daytime doesn’t need to be a specific amount of kWh, more about utilising as much excess solar without using too much expensive electric from the grid
 

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Discussion Starter · #3 ·
The Zappi will only start charging the car when there’s 1.4 kW of excess generation.

So it depends what your panels will generate.
but you can adjust the threshold i think? So if you set it to eg 50% then it would start charging at 700w excess and take the other 700w from the grid
 

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Jaguar i-Pace 21MY
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If you haven’t got an Eddi, then get one as that will consume excess solar rather than export it and obviously works in conjunction with Zappi. There will always be some export, but the Eddi will consume the amount below what the standard requires for EV charging.
 

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Eddi is a good call if the OP has a hot water tank.

However the issue really is the size of the array.

Put it this way - I have a 9 kWp array and on a good day currently it’s maxing out at 5.5 kW.

So a 2.6 kWp array is going to struggle to generate enough power to provide a meaningful charge for an EV.
 

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Discussion Starter · #7 ·
I don’t have a hot water tank. I realise the array is small so maybe it’s not practical? If I have to set the mix too low like 50% then the top up at 15p/kWh is effectively 7.5p. Not bad but overnight will be 5p so unless I can match that (which will almost always be enough to top up) then maybe it’s not worth micro managing things? Just put it on eco+ 75-80%, get some scraps form the table, then a boost timer for the cheap hours?
 

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Yep, I think so.

Out of interest, are feed in tariffs no longer available in the U.K.?

I get 7 cents per kWh and pay 9 cents per kWh for overnight use. So the margin isn’t huge.
 

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Discussion Starter · #9 ·
Yep, I think so.

Out of interest, are feed in tariffs no longer available in the U.K.?

I get 7 cents per kWh and pay 9 cents per kWh for overnight use. So the margin isn’t huge.
My panels were fitted for free - I get as much electricity as I need but the installers get the FIT.

if I was getting paid then I’d just consider the export as a ‘remote battery’ and charge with off peak :)
 

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I wouldn't waste my time charging at 6A. Use the electricity in the house instead with smart tech for appliances, DHW etc with occasional car charging. Use Octopus Go-Faster from 8:30 so as the solar tails off cheap rate kicks in :)
 

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I have 4 kWp PV which I do not get a feed-in for, so like you, I'm motivated to self consume as much as possible. I have both a Zappi and an Eddi, and I'm on Octopus Go.

Yes you can set the % green on the Zappi, so that it will allow some import. You need to do some sums based on what you pay per kWh to import, such that you're not wasting money. Since I pay 5p / kWh in the night charging slot, but about 15p (can't remember exactly) during the day, I've set the % green setting so that it will allow import up to ( night cost / day cost) * 1000W = about 333 W. Therefore I will never pay more that 5p per kWh I can put in to the car.
 

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I'm on a cheap(ish) single rate of 12.7p. I set my green threshold between 50% and 80% depending on how much charge I need and the upcoming forecast. I also use Eco mode and smart boosts to ensure I maximise solar use while ensuring that I have exactly as much charge as I need, when I need it. (On a single rate) there's no point in exporting anything at all if I'm going to import it again later.

If you're on Go or similar then just work out the ratio of your cheap rate to your peak rate (e.g. 14p peak vs 5p night is ~ 35%) and set the green threshold to the inverse of that (100 - 35 = 65%). So 70% green would guarantee that you don't pay more than the night rate.
 
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