Solar panels and battery - any real world reccomendations?
- Thread starter GinG
- Start date
Commissario
Anyone else had a utility supplier be really finickity about the SEG?
Just had a message back from British gas asking me to update the MCS because it states the installed capacity is 4.7kw when the panels add up to 4.74, so it looks like i'm going to have to contact my installer to get them to update it.
Just had a message back from British gas asking me to update the MCS because it states the installed capacity is 4.7kw when the panels add up to 4.74, so it looks like i'm going to have to contact my installer to get them to update it.
Soldato
Thats a pain, didn't fancy going with Octopus?
Commissario
we're with BG for gas and electricity and thought it would be easier to do the SEG with them.
Soldato
Do you have a battery? You'd almost certainly be better off with Octopus if so, probably even without a battery. What are BG paying per kWh?
I would look at how much you are going to be paid for an excess you export. That should be the number one decider imo.
Commissario
looking at octopus unless we move over to them we're looking at about 4 or 6p a unit, iirc at the moment bg are 6.7p a unit.
We're not looking at a huge amount of exporting given our usage pattern, so it's not worth us changing import supplier for a little bit extra on the export, especially if the import tariff is potentially higher than we already pay.
I'm going to contact the people who fitted the panels and ask them to do a corrected MCS, as I can see this potentially being an issue with other suppliers and apparently it should be fairly simple for an amended MCS.
We're not looking at a huge amount of exporting given our usage pattern, so it's not worth us changing import supplier for a little bit extra on the export, especially if the import tariff is potentially higher than we already pay.
I'm going to contact the people who fitted the panels and ask them to do a corrected MCS, as I can see this potentially being an issue with other suppliers and apparently it should be fairly simple for an amended MCS.
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Soldato
Finally had my GivEnergy 9.5kW battery and AC inverter installed on Thursday after months of waiting. Literally 5 minutes after the electrician left, the inverter through up a meter coms error. He remotely checked it but couldn't resolve it so visited the next day. Restarting the EM115 electric meter seemed to do the trick. I've now spent some time today setting up HomeAssistant on a spare Raspberry Pi I had. I've now got this running with GivTCP and solar integration so it will set the SoC overnight based upon what my forecast solar generation is for the next day. That way I'm not using too much overnight electricity to top up my battery (even if it is cheap rate). I'm sure it won't be perfect but will avoid me having to baby sit it. Will see how it goes over the next few weeks.
Soldato
@sparkymark75 Solar forecasts appear to be very unreliable, what tariff are you on?
Soldato
I’m on Intelligent Octopus, which makes things even more complicated on a night I’m charging the car!
Soldato
@sparkymark75 I'm glad I don't have to deal with the complications of factoring in a car, Flux makes it nice and simple, charge the batteries every night, discharge some in the peak period, rinse and repeat.
Soldato
With the fact your can use Outgoing Octopus (15ppkWh) with tracker import, ~20ppkWh, it's a hard argument that Flux is much better deal presently. I guess it depends a lot on battery size and peak discharge potential.
Soldato
@Journey One big benefit of Flux is simplicity, and given the size of my system appears to be working well.
Soldato
Yeah, I’ve not done any forensic maths on it but at a glance, I don’t see how Flux can work out cheaper for me with an EV. People seem to make money out of it but I wonder how much interruption to their normal daily routine they had to do to achieve that.
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Soldato
I'm talking Tracker not Agile, the tracker price is a fixed cost per kWh per day so not a lot of thinking required.
I'm still on cheapo Go Faster with low standing charge and peak rate so pointless for me to change to anything else Outgoing.
Soldato
Sorry, I was talking about Flux.
Soldato
Associate
You should try out the Solcast integration with HomeAssistant. I set my overnight soc based on the forecast and Solcast is massively more accurate than forecast.solar.
Associate
Have you tried Solcast? I find it to be pretty close to what is generated. There is just the odd day where it will be out by more than a few kWh.
Soldato
Absolutely none in my case, in fact its quite the opposite, we'd just got used to putting the dishwasher and washing machine on when the suns shinning, but now I charge the battery every night it doesn't matter, and once the additional battery is installed in a few weeks we won't have to worry about using too much either.
- Charge battery off peak (maximum charge circa 24kWh, 8kw x 3 hours)
- Solar tops battery up to full - capacity circa 29kWh
- Excess is exported at more than we paid per kWh to charge the battery
- Discharge some at peak rate, but keep some back to see us through to 2am and in case of a power cut.
- Repeat the above
I haven't yet tried Solcast, I came across an integration for Victron Node Red which uses Forecast.Solar and modded that, but may try Solcast, but given my use case as above its not really needed now.
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