Solar Panel limits in Summer

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 

​@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 

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.😊

​@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?

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.

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 

Thanks for the update ​@Peter E!

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?

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.

Just to say I believe it's normal to just export any surplus power rather than a percentage. I don't have solar so I can't go any further with that.

Peter

I can see no reason why all surplus power should not be exported!

If not, surely it cannot be generated, as it would have to go somewhere?

I have the SolaxCloud app, but only for my batteries (my PV has another inverter) but I cannot see anywhere that a percentage export can be set, or turned off.  Though there are many variations of models etc.

Thanks all. My understanding of the Solax Self Use or Self Consumption was that PV powers the house then PV powers the Battery then after Battery is full PV sends surplus to Grid. So “Mavison” you’d be right I think, why not get paid for all the surplus. The 50% I don’t export they get for free I suppose?

If you generate electricity it has to be used or exported. I do not think it can just be "lost".

Strictly speaking it can go nowhere. If you don't take power from the panels the power is still generated but it gets sunk into the panels themselves. If you want me to explain I will but it involves a describing how the panels work in the first place which is physics/electronics.

Peter

I was really referring to the power that is generated out of the inverter - ie about 240v 50hz AC. I have never looked at the panel side of the inverter.

You're right. It's got to go somewhere so if it's not used in the house then its exported. If you have a SEG agreement then you get paid. If not then one of two things would happen. If you have a smart meter then it goes to the grid but you don't get paid. Smart meters won't run in reverse and it may also set off an alarm for the situation to be investigated. If you have one of the old meters then you can get those to run in reverse and you effectively get paid at your tariff rate which is better than any SEG.

Peter