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Rank 3
April 28, 2026
Solved

Solar Panel limits in Summer

  • April 28, 2026
  • 28 replies
  • 337 views

Back again with a weird one. I’ve had to chase Octopus a couple of times for Outgoing payment since starting tariff in March. Which they have done when asked, just prefer not to be asking. Anyway since the last payment the Solar export figures have been way down. With the decent weather we’d been getting payments anywhere up to £1.15 per day. But as of last Weds after the payment they gave us most we have received is 19p. And we have had some amazing sun. Our usage hasn’t changed in the house but it’s dropped right off. It’s not as though it’s not doing its thing it’s just not as much as I would of expected considering it’s getting warmer.
Does something weird happen to panels if it’s very hot? Any insight would be really appreciated.

Also they’ve been in a year now do they ever need cleaning?

 

Best answer by juliamc

This is my export for last week, as you say we’ve had loads of sun. My panels are covered in pollen and/or dust as we’ve had no rain for days, and I imagine they’ve got very hot up there. 

I believe they’re less efficient when they’re hot but not so much as to make the difference you’re seeing. 

 

28 replies

juliamc
Rank 20
juliamcSolved
Rank 20
April 28, 2026

This is my export for last week, as you say we’ve had loads of sun. My panels are covered in pollen and/or dust as we’ve had no rain for days, and I imagine they’ve got very hot up there. 

I believe they’re less efficient when they’re hot but not so much as to make the difference you’re seeing. 

 

BPLightlog
Super User
Super User
April 29, 2026

There are various things to consider .. the house taking more from the solar pv for example, do you have batteries? This can also change things.

The panels do generate less when they are hot and they do need cleaning from time to time but the drop off from that shouldn’t be as significant as Julia has mentioned 

Bring me Sunshine ~ E&E {Solar PV, Battery Storage, Hybrid EV, ASHP and Home Assistant automation}
Peter E
Super User
Super User
April 29, 2026

@Tricko 

 

Are you on the Flat Rate (12p) or the variable Agile Outgoing? It says Outgoing but I don't know how to recognise the difference. 

 

Peter 

Reducing my yearly fossil fuel usage with an EV (-900 litres petrol), A2AHP (-8,700 kWh gas) and Timed Immersion heater (-1,500 kWh gas)
Abby_OVO
Community Manager
Community Manager
April 29, 2026

Hey ​@Tricko 

 

I’m glad to see a few of our community members have already stopped by with some helpful advice. Thanks ​@juliamc that’s a really helpful visual comparison!

 

It definitely sounds like it’ll be worth having a check with Octopus just in case they can see or suggest.

 

Hopefully the comments so far have been helpful, do keep us updated with how you get on.😊

Currently Playing: She's Electric
Rank 2
April 29, 2026

@Tricko said  I’ve had to chase Octopus a couple of times for Outgoing payment since starting tariff in March

It is only April now!  Or do you mean March 2025?

If so, your payments should automatically be on each monthly bill, as mine are, assuming your meter is being read automatically as it will be smart, and you also pay Octopus for electricity imported.

Your weekly graph shows a drop in £ after the first 2 days - is there a similar drop in the kWh readings? If not, then the rate must have changed. Or has your household usage of electicity increased, leaving less spare to be exported.

You should have some way  from the Solar providers of seeing what is being generated by hour, day, week, month etc. Does that show a similar decrease?

Ben_OVO
Community Manager
Community Manager
April 30, 2026

Thanks everyone for your help on this thread - much appreciated. ​@Tricko - we look forward to hearing back from you, and hopefully we can help you get to the bottom of all this.

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Peter E
Super User
Super User
April 30, 2026

The Octopus export rate was cut from 15p to 12p on the 1st March effectively due to increased solar from more solar farms coming on line. 

 

https://energy-stats.uk/solar-export-rates-cut/

 

Peter 

Reducing my yearly fossil fuel usage with an EV (-900 litres petrol), A2AHP (-8,700 kWh gas) and Timed Immersion heater (-1,500 kWh gas)
Ben_OVO
Community Manager
Community Manager
April 30, 2026

Thanks for the update ​@Peter E!

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TrickoAuthor
Rank 3
May 7, 2026

Thank you all for your replies. Yes it’s Octopus flat rate 12p.Yes we have a battery and the Inverter is Solax. Our Cloud app shows Export as turned off. Not something we’ve done and the app won’t let us save any changes.

The inverter touchscreen does let us save, but with export turned on it asks for a percentage, clearly it shouldn’t be zero because that switches to No Export but we don’t know what it should be either. I’m assuming it’s how much of the surplus we want sent as export after Load and Battery is charged up?

 

 

Chris_OVO
Community Manager
Community Manager
May 8, 2026

Hey ​@Tricko,

 

I’ll tag ​@juliamc, ​@BPLightlog and ​@Peter E so they know you’ve popped an update on the thread.

 

Most solar and battery apps let you control how much extra energy your system can send back to the grid once your battery is full. If you set the export percentage to 0%, you'll keep all the energy for yourself. On the other hand, 100% means you're sharing everything with the grid. It’s a good idea to take a look at your energy usage and play around with the export percentage each month until you find what works best for you. And don’t forget to adjust it for the changing seasons.

Renewable energy jokes never get old.