Nigel, out of interest what is the peak power draw from your batteries?
4kW.
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I thought you had a 6kW inverter.
Phil
Inverter’s capacity and peak battery power draw are two separate things.
My inverter is 5kW and my battery peak power draw is 3.8 kW
That’s interesting because with SolarEdge the inverter determines how much power can be drawn from the battery. Occasionally our peak house power exceeds 5kW which means that as long as the battery has energy we don’t use power from the grid. The inverter’s tracking of the grid means that we draw 250Whs over 24 hours.
Phil
It’s electrics and therefore I’ve no idea how it all works. The inverter is indeed 6kW. The batteries can charge and discharge at 4kW, in fact 4.066kW.
We have reduced our monthly direct debit to Octopus to £20 a month, but as we have £770 in credit it seems silly to keep paying them money. So I’ll probably go back to my original plan to pay on actuals. Hopefully the £770 will get us to the point when the monthly bill starts to go positive, which happened in April this year.
Yes indeed, but there will be a peak power DC input into the hybrid inverter, and the battery(ies) will also have their peak power draw. When the panels are generating, the inverter will be powered by the panels with any shortfall from the battery upto the max draw of the battery and inverter capacity.
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I wonder whether this month is particularly gloomy. We only generated 361kWh in October and later read that it was the least sunny October in 60 years. Production this month, November, seems even worse, with only 141 so far, and the month is 2/3 over. The forecast for the next couple of weeks looks like gloom, gloom and more gloom.
These recent cold days have meant that the batteries run out in the evening so we have to use 29p power. Still, it’s cheaper on balance to use Go than Cosy. We need more sun!
September 578kWh
October 251
November 181
Here in Gloucestershire
Perhaps the SoleEdge optimisers help.
Managed to export 216 before the cold snap but have run out after dark to varying degrees in the cold snap. 9C at the moment and the ASHP is hardly running. Quite agree that Intelligent GO is better than Cosy. We started November with a £402 surplus and that should get us through until we have permanent freezing conditions without sun for two months, which seems most improbable.
Phil
Looking back at my figures, it’s all down hill and doesn’t start to pick up until Feb. Winter days for me is more about the thrill of the In House Display not showing too high in negative numbers, with the odd chance of charging a few batteries, and a day a week where hot water gets to 60degrees
That’s quite similar. We did 615 in September. Our credit at Octopus had reached £770 at the end of October so we’ve had a £270 refund, leaving £500 in the kitty. We’ve stopped paying our £25 a month and will let the £500 run down and then pay any negative bills monthly. I’m very much hoping that we can get to the end of the year without spending anything on power, but it’s going to be a close run thing.
The faulty inverter and subsequent control issues probably cost £150. We don’t have as much generation as you. I certainly agree with paying off on a monthly basis when the account goes negative as it stops them changing the DD.
Phil
Octopus direct debit levels are a mess for us. They seem to make adjustments twice a year, and because they get it so badly wrong we end up paying far too much in summer, and very little in winter. Fortunately you can change the level yourself on their app, so every time they set it to something ridiculous I can set it back to something sensible.
We have been with Octopus for three years and they have never once changed our direct debit, though we’ve heard plenty of horror stories.
Here on the Suffolk coast our exports have been -
September 357kWh
October 145 kWh
November so far 21 kWh.
so in November we are consuming most of all that we are generating in the day, battery charged over night - and tends now to be dropping to 20 to 30% before it charges up again from the grid on E7.
I have been Octopus for 14 months now and I have adjusted down my DD to match their recommended payments - but it has only been me that has changed it… They recommend I should make no monthly payments currently given the balance I have built up through mostly generation over the last year - however I pay £10 a month by DD. Not sure why really - but I do.
Clearly my balance will decline over November / December / January / Feb … but I will still be well in credit based on last years usage figures before the balance starts increasing again. At that point I’ll probably transfer some of the balance.
I have noticed hardly surprisingly if there is a thick frost on the panels even when sunny first thing in the morning not much gets generated 
We generated 72kWh this week which covered most of the cold snap. Today is warm enough to only need the ASHP on overnight till 10am. Only need about 1/3 of the electric for heating.
Phil
I note that Eon have significantly reduced their export rates, as did Scottish Power a little while back. Also, I understand Octopus have an invitation only seminar on Monday to talk about future export rates. Interesting times as they say.
Yes interesting.. a huge range of exports tariffs, with the best for 12 months being 40p per kWh , yet no condition tariffs like with Scottish power down at 6p per kWh… quite hard to navigate and the best rates have certain conditions.
Around 15 p per kWh seems quite common though.. Albeit you need to be an importer customer, though in real terms compared to import costs this price has eroded significantly over the last few years…
We’ve generated 42kWh over the past seven days, with the heat pump using 124kWh for heating and hot water. Fortunately the majority of the other 82 was 7p overnight power. The heating is set to run at 19° in the morning, 18° in the day, 19.5° in the evening and 16.5° overnight, and we just let it do its thing without any intervention. The colder it gets outside the hotter the flow temperature, and vice versa.
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