Solar panels and battery - any real world reccomendations?

I'm guessing I'll be fully charged in the summer by midday (I've had it a few times in Feb already). And from 4pm I'll be exporting at least for an hour or so hope if the weather is good?

For me it makes sense. Even if I can't fully charge the battery if be able to top it up enough to carry me through the day. The only issues will be weekends in the afternoon in the winter time. But I'd hope that the 8 months of the year would cover me enough in terms of average savings.

Ultimately I'm going to give flux a go and see how it goes. I can always change tariffs if it doesn't work out. Even the basic export rate is over ,50% more and the regular rate is around the same as mine at the moment.

It's going to be no worse for me than I'm on now. And I'm happy with octopus.
 
Last edited:
Yeah there is at least one more consideration as well.

Right now, being on go is easy. It gets a little less easy with the newer charging tariff rates but its still pretty easy to get close to optimum with no effort.

On go you charge your batteries in the cheap window, then as soon as its over you can start discharge. There is no penalty for using eg 8kwh and being out of battery at 4pm, or using at a slower rate and running out at 8pm. You pay exactly the same 44p a unit for your none go period rates.
So you have no worry on time of use, and as such if you discharge a good chunk then top back up to 100% great. Its literally optimum to allow your batteries to discharge as early as possible. More chance to harvest and store your solar generation.

On flux thats not true. You can charge in flux, but you need to ensure you have enough generation or battery power for 4pm-7pm. You absolutely do not want to be paying grid price then, where as on go you dont care what time grid units are since they are all the same price.
So you need more micro management. If you see a weak generation day you probably may need to go on grid for a while to make sure you have enough battery for the 4-7pm slot, but not too much that you end up getting to the charge period with energy you charged in the last charge period.
Its going to be a lot more difficult to manage that day to day without some effort.
 
Could work around the peak rate stuff by adding 2nd charge window to the battery to maintain a certain % value before the late peak rates if needed.

Other problem is I can't 100% avoid using grid energy, at least now when the sun isn't shining. I tend to cook dinner after 5 and that uses more than the base load + battery can provide almost always.

In the summer I think there is still often some generation then so doesn't kick in much from the grid as a result.
 
HungryHippos said:
Could work around the peak rate stuff by adding 2nd charge window to the battery to maintain a certain % value before the late peak rates if needed.

Other problem is I can't 100% avoid using grid energy, at least now when the sun isn't shining. I tend to cook dinner after 5 and that uses more than the base load + battery can provide almost always.

In the summer I think there is still often some generation then so doesn't kick in much from the grid as a result.
Click to expand...

Thats going to be manufacturer limited potentially though.
I can set my max and min charges, and I can set two sets of charge and discharge and usage windows, but they both use the same % charge min max.
Must admit I am only using the "self use" plan. There are others like manual, but I don't think they give any more granularity on those timings.

Its another thing to consider for sure, your GE battery limit being under half my solax one. I can pull 5.5kw from the battery so I don't think I have yet managed to exceed that apart from when specifically trying. If I have its been negligible in length to not show up on octopus 30 min billing graphs.
 
On the Victron you can set up to 5 scheduled charging periods, tell it a SOC to charge to, or for how long. But there is no built in scheduled discharging, can you believe that?

Fear not though, it can be done, just need to wrap my head around Node Red, then that can be used to tell the inverter to discharge, how much and for how long, just a bit of programming until Victron catches up.
 
Ron-ski said:
On the Victron you can set up to 5 scheduled charging periods, tell it a SOC to charge to, or for how long. But there is no built in scheduled discharging, can you believe that?

Fear not though, it can be done, just need to wrap my head around Node Red, then that can be used to tell the inverter to discharge, how much and for how long, just a bit of programming until Victron catches up.
Click to expand...

Equally on the Solis you can specify multiple charge/discharge windows and associated charge/discharge rates, but can't set a specific SOC % to charge to... bizarre really.
 
Mercenary Keyboard Warrior said:
Thats going to be manufacturer limited potentially though.
I can set my max and min charges, and I can set two sets of charge and discharge and usage windows, but they both use the same % charge min max.
Must admit I am only using the "self use" plan. There are others like manual, but I don't think they give any more granularity on those timings.

Its another thing to consider for sure, your GE battery limit being under half my solax one. I can pull 5.5kw from the battery so I don't think I have yet managed to exceed that apart from when specifically trying. If I have its been negligible in length to not show up on octopus 30 min billing graphs.
Click to expand...

GE doesn't currently let you have more than one either, though you can sort of workaround it with home assistant :)
 
Ron-ski said:
On the Victron you can set up to 5 scheduled charging periods, tell it a SOC to charge to, or for how long. But there is no built in scheduled discharging, can you believe that?

Fear not though, it can be done, just need to wrap my head around Node Red, then that can be used to tell the inverter to discharge, how much and for how long, just a bit of programming until Victron catches up.
Click to expand...

I just use 2X 16A SonOff switches to control charging, discharging, easy to set up via mobile app and have been trouble free for a year.
They just turn on/off daily to the times you set.
 
Last edited:
Rather tha quoting mkw etc, as I'm not on go I think I'll move to flux in April, once I start seeing regular generation filling my batteries and the car. In theory should fulfil my needs and with my battery storage can force export to the grid in the evenings for a bit as well as any excess solar. If needed can top the car up in the 3 hr window if the wife needs it the next day.
 
Ron-ski said:
@Troop I knew there's no way it would work on my system, was curious how you had it working/wired up though.
Click to expand...

One Sonoff turns the inverter on 2.30am-9.30pm, other one turns on the charger(if needed) 9.31pm-2.29am.
I'm on GO faster, the batteries run the house 2.30 am to 9.30pm, use the grid cheap rate(8p) for the other 5 hours(immersion/washing machine)
 
Last edited:
SoliD said:
Rather tha quoting mkw etc, as I'm not on go I think I'll move to flux in April, once I start seeing regular generation filling my batteries and the car. In theory should fulfil my needs and with my battery storage can force export to the grid in the evenings for a bit as well as any excess solar. If needed can top the car up in the 3 hr window if the wife needs it the next day.
Click to expand...

Yes I think if you have an ev it's more tough a call. Since I can't be on Go anyway it makes sense for me. Anyway I'm going to give flux a go and see how it goes.
 
SoliD said:
Rather tha quoting mkw etc, as I'm not on go I think I'll move to flux in April, once I start seeing regular generation filling my batteries and the car. In theory should fulfil my needs and with my battery storage can force export to the grid in the evenings for a bit as well as any excess solar. If needed can top the car up in the 3 hr window if the wife needs it the next day.
Click to expand...

You have a big array as well so I imagine your export capacity is good :)
 
You must log in or register to reply here.
Back
Top Bottom