Ah yes, my mistake !8.2 states 100% Dod. Only the 5.2 and 2.6 say 80%? I'd double check though. Might go for the 9.5 just for symmetry
tricky as my octopus is 13th-12th for billing, and the givenergy/myenergi dashboards are calendar months so I don't have a full one yet. I can estimate from weekly.. hold on
Depends. The earlier 8.2kW gen 1 batteries like mine were 80% DoD. There have been a lot of SKUs. It's hard to keep up!
Depending if you have the Gen1 or Gen2 Hybrid Inverter, you're limited to 2.6 or 3.6kw charge speeds. 2 x 9.5 won't fit in the 4hr window of octopus go.8.2 states 100% Dod. Only the 5.2 and 2.6 say 80%? I'd double check though. Might go for the 9.5 just for symmetry
tricky as my octopus is 13th-12th for billing, and the givenergy/myenergi dashboards are calendar months so I don't have a full one yet. I can estimate from weekly.. hold on
last four weeks, most recent at top. The bottom entry is a bit odd I had an issue with the battery which needed resetting remotely so perhaps ignore that one
View attachment 946118
Nice.
I’m thinking like this as an example which applies in your situation….
Might be worth an “insurance” cheap overnight charge. Maybe ‘50%’ ? Or whatever you might lose in generation or need to get to the next days sun up/ cheap window again.
20kW overnight “insurance” buffer charge will cost £1.5 on IO.
If it’s cloudy/thundery you’ve covered yourself at 7.5p/ kW. If not it’s stored in the battery “bank” for later.
If you generate over what you need, and battery ‘overflows’ you can dump it all in the car or export it at 4p. So even if you have to dump all of the excess to export; those 7.5p/kW you end up exporting will only cost you 3.5p/kW as an insurance policy.
So a 20kW “insurance” cheap overnight charge would (worst case) cost you 70p for the day. Less if you export less. Or nothing if you dump it in the car.
However if you have to buy all those 20kW at 42p then it’s an £8.40 cost.
The cost benefit of having a bit extra in reserve (even if you have to export it ALL) is massively skewed to having a bit extra and having to dump it in the car or export it back rather than having to buy at 42p.
If you get it wrong by importing too much, say 8 times a month it’s negligible (or max of £5.60), if you get it wrong and are short that’s £67 !
I think this will come into play a lot more in the shoulder months. Thoughts?
In other news… hopefully my install is happening within the next couple of weeks.
Yay
Give seemed reasonably confident that the AIO would pair reasonably well with a hybrid inverter. The hybrid doing high efficency battery storage from the Solar, the AIO being more grid tied storage with the option to store from the Solar.
Yes, definitely worth it, I'm on IO, and so far my bill for 11 days is £5.47. I should have switched to Agile with a lower standing charge as it would have saved me 65p so far this month.
our DNO assumes the PW can export at 3.6kW or 5kW even if set to zero, so the 6kW calculation is 5kW for the PW and 1kW for the solar.
The problem with AC coupled batteries working with hybrid inverters is that they tend to just drain the DC batteries. Hybrid inverters hide the DC batteries to the AC system and make it look like it's solar. So the AC ones will merrily charge away from them.
Their argument is that if the PW is outputting at, say 5 kW, to satisfy house load, and that house load goes away, then for a very brief period of time the PW is exporting 5 kW.
Right now, they assume that all devices could export at their maximum rate for an extended period in a fault condition (CT clamp failed, etc). Those fault conditions aren't wildly unrealistic, and you can see why they would want to handle it that way. (If you don't do it properly, there could be an impact on safety)
Yes, I did query how they planned to deal with this and didn't get a plan for this scenario, just a fairly generic answer that they saw this as a good solution.
As it appears that this question was for me, yes the installer measured it and the inverter app also shows grid voltage every 5 minutes.
