Solar panels and battery - any real world recommendations?

You can't import and export at the same time, I've found that if you plug in during the day, Octopus will schedule a charging session if your exporting, and that will mean you excess solar goes into the car, rather than earning 15p per kWh.

I've also found that Octopus will schedule an early evening session when I exporting in the evening.

I now don't plug the car in until I go to bed, my Victron system is also programmed to charge the house battery at 4kW when there is an intelligent charging slot, it takes the current house load including the EV charger and adds 4kW to it, then sets that as the grid point. If Octopus schedule a charge for 22:30, I guarantee they stop it by 23:00, then my system exports like crazy to try and get the battery down to 15% SOC by 23:30 :cry:

Depending on your charger, it may also try to steal your solar exports, I had to alter the settings on my Zappi to get it to do what I wanted.
 
Did you had to install an extra clamp so that the Zappi can monitor the solar production?

I have one clamp that monitors the house consuption or the grid import - that lets it display in the app the car consumption, the house consumption and the total power coming from the grid.
 
Its not required. The Zappi will take anything being exported as long as you have the single clamp that monitors house consumption and the grid, depending on the export margin setting. I have mine set up to 8kW as it was stealing export when I didn't want it to. I also don't plug in until before bed like Ronski as Octopus always scheduled a slot when I was exporting too.
 
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Mines as above as well, I set mine as high as it would go though, which is 10kW, although I can export more than that.

Zappi has one CT clamp, so can just see what's going out or coming in from the grid.

As a side note, due to my setup there's no way the Zappi can see solar generation, my Victron inverter literally sits in the grid feed to the house.
 
john_smith said:
Weird. I was speaking to an installer about this yesterday. EON rejecting applications based on expected generation being under estimated.
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Any more details? I switched to eon a few months back, so have been charging overnight and discharging any spare battery late in the evening, will shortly be submitting my first export meter reading (as for some reason they don't seem to use the smart meter for export). Guess that adds 3-6KWh per day to my export at this time of year (normally 30-35 on a decent day, from a 5.4KWh south facing array with 5kw inverter), so now a little worried they might try and get out of paying for the export, especially as my export has been very good recently because of the weather.
 
Tavis75 said:
Any more details? I switched to eon a few months back, so have been charging overnight and discharging any spare battery late in the evening, will shortly be submitting my first export meter reading (as for some reason they don't seem to use the smart meter for export). Guess that adds 3-6KWh per day to my export at this time of year (normally 30-35 on a decent day, from a 5.4KWh south facing array with 5kw inverter), so now a little worried they might try and get out of paying for the export, especially as my export has been very good recently because of the weather.
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Basically they'll pay you up to whatever your MCS certificate says you can generate in a year. Unlike Octopus they don't want people dumping their batteries at 11pm :cry:
 
I have 6 Aiko panels on a south facing roof and 5 on south-west facing. There are no shadows. Comparing the solar streams, one of them always has higher voltage and the other higher amperage. Why is that?

Also wonder if it's normal for 11 465W panels to produce 3.7KW on a sunny day at noon.

PCTliBJ.jpeg
 
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Thats the point of an MPPT to move the voltage around (and hence affect the A) in order to maximise generation.

More wordy version :

"An MPPT, or Maximum Power Point Tracker, is a crucial component in solar power systems, particularly those involving batteries, that optimizes energy extraction from solar panels. It acts like a smart converter, ensuring that solar panels operate at their peak efficiency by continuously adjusting the voltage and current output to match the battery's charging needs, even as sunlight conditions change."
 
I've just been looking through my paperwork, and seems like I just have G98, but my export
200sols said:
Basically they'll pay you up to whatever your MCS certificate says you can generate in a year. Unlike Octopus they don't want people dumping their batteries at 11pm :cry:
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OK, hopefully will be fine then, my generation\export over the last 2 years has been below my MCS estimate, though potentially could exceed it this year with the extra battery export and the fact the weather has been excellent.
 
SkyTerran said:
I have 6 Aiko panels on a south facing roof and 5 on south-west facing. There are no shadows. Comparing the solar streams, one of them always has higher voltage and the other higher amperage. Why is that?
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Quite simple really.

When panels are arranged in series, which is the case for most normal installs, the voltage adds up per panel, maximum current will remain the same.

Let's say each panel can create 40v.

One is a string of six panels, so 40 x 6 = 240v
Other string is 5 panels, so that is 5 x 40 = 200v

In identical orientation and pitch, no shading, they'd both generate roughly the same current though, as that stays the same in series.

Watts is voltage times current.

A slightly different pitch will mean the sun hits the panel at a different angle, change the direction of the panels, and it has an even bigger difference, these difference affect the current (amps) being generated. Then the MPPT is involved trying to find the maximum power point, so that can cause variations as well.
 
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Tavis75 said:
I've just been looking through my paperwork, and seems like I just have G98, but my export

OK, hopefully will be fine then, my generation\export over the last 2 years has been below my MCS estimate, though potentially could exceed it this year with the extra battery export and the fact the weather has been excellent.
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I've see on the Facebook group they are 'allowing' 10% over because of the weather...

The people having problems are those submitting 3monthly, obviously the last 3 months have been endless sun and they are being caught by this algorithm Eon apply before paying.

However after they've explained e.g they export all their generation and charge battery everyday I've not seen anyone declined payment.
 
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www.fogstar.co.uk

Fogstar Energy 51.2V 32kWh Battery

32kWh 51.2V Fogstar Energy Battery, ideal for off-grid living, backup power, renewable energy systems and industrial energy management, this battery ensures reliable and efficient energy storage for various residential, commercial, and industrial needs.
www.fogstar.co.uk www.fogstar.co.uk

Anyone heard of/had any experience with this mob? Seems a reasonable price for that amount of capacity and convenience.
 
Yes, I bought a total of 32 EVE 280k cells from them in August 2022 and February 2023.

@Oldman2 purchased some batteries from them a few years ago when they brought out the rack batteries.

Somebody else recently bought some batteries, it may have been @1pudding1

One thing to be mindful of is the weight, the one you linked to is 233Kg.

It may be a better idea to get two of these https://www.fogstar.co.uk/collectio...gstar-energy-seplos-48v-16-1kwh-solar-battery

Same capacity, same price, but two units, so each is half the weight.

PS. Ensure you've got a compatible 48v inverter, otherwise they are useless.


.
 
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There are so many useful things an enterprising engineer can create with cheap and powerfull batteries like this. But unfortunately in UK that's practically imposible, due to all the regulations. So all the cool new drones, EVs, flying cars, etc. will be coming from China and USA.
 
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