Solar panels and battery - any real world recommendations?

With the Octopus changes I might just revert back to good old fashioned timed charging 2330 to 0530 to ensure I maximise the 6 hours. Intelligent feature will be turned off. Shame, but I have enough battery storage to last on cold days. Will hit the electric heating peeps I guess unless they have significant storage.

At least we can still charge the house batteries during the 6 hours, that was my fear. I think even that will change though in the future as more people switch their usage times with the uptake of EVs and heat pumps.
 
Last edited:
Nathan said:
With the Octopus changes I might just revert back to good old fashioned timed charging 2330 to 0530 to ensure I maximise the 6 hours. Intelligent feature will be turned off. Shame, but I have enough battery storage to last on cold days. Will hit the electric heating peeps I guess unless they have significant storage.

At least we can still charge the house batteries during the 6 hours, that was my fear. I think even that will change though in the future as more people switch their usage times with the uptake of EVs and heat pumps.
Click to expand...
Oh so you turn off scheduling but because it’s off peak 2330-0530, it doesn’t matter? Never done it without scheduling before. You control the timing via Octopus app or your charger? Charger I assume.
 
Ali195 said:
Oh so you turn off scheduling but because it’s off peak 2330-0530, it doesn’t matter? Never done it without scheduling before. You control the timing via Octopus app or your charger? Charger I assume.
Click to expand...
Yeah the charger, then set the inverter to charge the house batteries between those times.
Unless, octopus do put a manual change to limit to 6 hours, then I guess I can just continue using HA to manage it.
 
It’s not being implemented until the end of Jan and presumably the app will be updated before then as add the 6 hour limit toggle before then.

If your system is already compatible with the smart charging system, I see only disadvantages to turning it off. You’ll only over get more 7p slots for home use not less.

So yeh, I’m not sure I ‘get’ why you’d do that.
 
b0rn2sk8 said:
It’s not being implemented until the end of Jan and presumably the app will be updated before then as add the 6 hour limit toggle before then.

If your system is already compatible with the smart charging system, I see only disadvantages to turning it off. You’ll only over get more 7p slots for home use not less.

So yeh, I’m not sure I ‘get’ why you’d do that.
Click to expand...
It depends entirely how they set up the charge slots, I guess I would be better off using HA if it can see i no longer have any cheap slots left…Then I can access the cheap slots early evening like I do now, when there is still household demand. If i run out of cheap slots, then most of the time that would be middle of the night when there is little to no demand as long as both cars are charged.
 
Nathan said:
It depends entirely how they set up the charge slots, I guess I would be better off using HA if it can see i no longer have any cheap slots left…Then I can access the cheap slots early evening like I do now, when there is still household demand. If i run out of cheap slots, then most of the time that would be middle of the night when there is little to no demand as long as both cars are charged.
Click to expand...
But you still get cheap electricity for your house between 11.30 and 05.30 regardless of how many cheap slots you do or don’t use for charging your car.

Like I said, I don’t see any advantage of turning off smart charging because all that means if you get less cheap slots for home use. Charging your car isn’t impacted, it’s 6 hours max either way.

Edit: just to add it’s also 6 hours of actual charging, those 6 hours could be spread over more than 12 slots. This is clarified in the Q&A IIRC.
 
Last edited:
Hey folks, if you had a new system that under-generated by around 20%, would you go back to the installer to investigate?

I've got an E/W split array of 6.14kWp total, the MCS certificate was submitted on 4300kWh per year. First full year though was this year which by all accounts was a pretty good one and that has only generated 3700kWh. I need to check the pvsol numbers that went into it but I think that was meant to be a net forecast number. I get a bit of shading on two panels but I thought that had been built into the model because it shows the shade up on the rendering
 
b0rn2sk8 said:
But you still get cheap electricity for your house between 11.30 and 05.30 regardless of how many cheap slots you do or don’t use for charging your car.

Like I said, I don’t see any advantage of turning off smart charging because all that means if you get less cheap slots for home use. Charging your car isn’t impacted, it’s 6 hours max either way.

Edit: just to add it’s also 6 hours of actual charging, those 6 hours could be spread over more than 12 slots. This is clarified in the Q&A IIRC.
Click to expand...
Oh I did not realise this…
I read it as you only get 6 hours in the 24 hours. So, if your 6 hours are during the day, then at night it’s the high charge?
 
Nathan said:
Oh I did not realise this…
I read it as you only get 6 hours in the 24 hours. So, if your 6 hours are during the day, then at night it’s the high charge?
Click to expand...
Yep. So really then it's little and often than leaving it for once a week, for example. Personally, we just like to charge it over the course of day, letting the schedule take care of it. Once the app is updated we can do the same, but hard limit it to 6 hours so regardless of it being day or night, we'll never get the standard/high rate.
 
Nathan said:
Oh I did not realise this…
I read it as you only get 6 hours in the 24 hours. So, if your 6 hours are during the day, then at night it’s the high charge?
Click to expand...
It’s 6 hours EV ‘smart’ charging, it’s always cheap for house use from 23:30 to 05:30.

The smart charging hours may or may not be during the hours which are always cheap. If you smart charge outside the cheap hours, your house electric is also cheap in that 30 min block.
 
Nathan said:
Oh I did not realise this…
I read it as you only get 6 hours in the 24 hours. So, if your 6 hours are during the day, then at night it’s the high charge?
Click to expand...
Yes if they give you 6 hours during the day they'll charge you after that if you still need more charge but tbf that does mean 6h x 7kW = 42kWh so at least >120 miles even in winter every day. But the good thing is that your house load will get the benefit of either though, both the night time hours *and also* any daytime car charging hours. That's how I've understood the latest terms
 
shroomz said:
Hey folks, if you had a new system that under-generated by around 20%, would you go back to the installer to investigate?

I've got an E/W split array of 6.14kWp total, the MCS certificate was submitted on 4300kWh per year. First full year though was this year which by all accounts was a pretty good one and that has only generated 3700kWh. I need to check the pvsol numbers that went into it but I think that was meant to be a net forecast number. I get a bit of shading on two panels but I thought that had been built into the model because it shows the shade up on the rendering
Click to expand...
That does sound rather low, it would be worth getting it checked out. Usually, especially this year you should really have exceeded the estimate.

Do you have any panel level monitoring, or an you check what the two strings have generated?
 
shroomz said:
I get a bit of shading on two panels but I thought that had been built into the model because it shows the shade up on the rendering
Click to expand...

if these two panels are on the same string as the other panels without optimisers that it can possibly affect the efficiency of the other panels
 
shroomz said:
Hey folks, if you had a new system that under-generated by around 20%, would you go back to the installer to investigate?

I've got an E/W split array of 6.14kWp total, the MCS certificate was submitted on 4300kWh per year. First full year though was this year which by all accounts was a pretty good one and that has only generated 3700kWh. I need to check the pvsol numbers that went into it but I think that was meant to be a net forecast number. I get a bit of shading on two panels but I thought that had been built into the model because it shows the shade up on the rendering
Click to expand...

What system?
Means you will likely get some help from someone with the same here

As ronski says in regards looking at strings etc

I would say 4.3mwh sounds about right for installed kicking off a bit for shading as an installer quote, they do tend to quote well below.

I have 5.5kwp west facing but east/west/mix makes little diff and annual is 4.5-4.8mwh so far for annual production.
I also get shaded from the South in winter months and a tiny bit from due west in spring and autumn.

I assume your shading is partial, as in it transitions around and also its only affecting one side?

Oh you didn't mention inverter size btw. If your installer has put in a 3.6kw then that may be correct generation as its going to limit it a lot at times.
 
shroomz said:
Hey folks, if you had a new system that under-generated by around 20%, would you go back to the installer to investigate?

I've got an E/W split array of 6.14kWp total, the MCS certificate was submitted on 4300kWh per year. First full year though was this year which by all accounts was a pretty good one and that has only generated 3700kWh. I need to check the pvsol numbers that went into it but I think that was meant to be a net forecast number. I get a bit of shading on two panels but I thought that had been built into the model because it shows the shade up on the rendering
Click to expand...
You can also put your system into something like PVGIS which will estimate its annual output to give you can idea of what the theoretical capability of the system is.

As a general rule, east/west produces around 70% of south facing.
 
You must log in or register to reply here.
Back
Top Bottom