Just one thought, how does the ASHP get the immersion water above 60 degrees?
It has to be programmed to do it once a week I think
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Is the Eddi similar to the ISolar boost?
I have the latter and find it heats the water to 62c by lunchtime on a sunny day , Then in the afternoon I can charge the car from Solar with my Smsrt Indra Charger
Not really sure 
but it diverts surplus generation to the immersion element in the water cylinder
Then yes it’s the same
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I have recently got a Solar Edge diverter and now have free hot water, whereas before I was using my oil boiler to heat waterand pretty much giving away my surplus solar. It’s not as good as a battery but I’m waiting for bidirectional charging cars to fulfill that role. In the meantime the diverter was installed for £500 so should pay for itself before too long.
UK: Clocks going forward means that for all us non-battery folks, get to potentially cook our dinner under Solar power - Yipee! (just not today - a bit cloudy 
)
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And of you use Economy 7, then with my DNO at least, that means i have until 08.30 before i go onto standard rate if importing. So breakfast can be had on the economy 7 rate ( assuming the sun is not up)
I learned recently that smart meters have a randomised offset built into them that means your 30 minute periods don’t all start on the actual half hour. The offset can be up to 30 minutes.
If you draw at two known constant power levels before, during and after the actual half hour (say 0, 1, 0 kW), and maintain them for a half hour, and you get your half hour reading you can calculate the offset as the actual energy will be the proportion of an hour in minutes given be the meter reading. Obviously the following reading will be the remainder. The Octopus App shows your usage through the day.
Very essential if you plan to exploit Agile rates to time things accurately.
Phil
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Interestesting, and that can potentially work out expensive if you charge your batteries during an indicated low cost moment. Is that random offset then fixed that value forever or does it change daily/hourly etc?
Fixed for the life of the meter. It is not known to anyone but the person who measures it. It’s purpose is to prevent big surges on the grid when those with Time of Use Tariffs switch on.
Phil
Well, I switched to Octopus Flux last night after getting my MCS and DNO paperwork the day before. I also read that the Tesla Tariff is no longer available as Octopus had spotted that Tesla may have plans for its own energy business and the previous 11.5p/kWh was rocketing upwards.
I now have to wait for SolarEdge to give me control over my battery system so I can manage my grid export optimally. We have had days recently of generating 40kWh DC.
Phil
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40kWh! Blimey.
I’ve seen a handful of days over 35kWh this month. I’ve managed to do a fair amount of car charging on top of running the house so I’ve been quite happy.
I’m not sure about flux at the moment and think I’m likely to stick with ‘Go’ due to the lower rate for 4 hours overnight. It might make sense to switch between Flux in the summer and Go in the winter but I suspect the savings would be relatively small (for me). I think with a larger battery you might be able to take more advantage by buying off-peak and selling in peak hours though.
Today has produced 37.58kWh DC while yesterday was a fraction under 40. Despite the cloudy forecast today, there was some blue sky and it was 16c by late afternoon. We haven’t run the ASHP for heating today, and exported 18kWh and still have 97% on the battery (2x10 kWh). Flux pays 22p/kWh almost with 35p almost from 4-7pm. So a good start.
I have wondered what to do about charging. As you suggest it can be sold back at a few pence more than it was bought at any time, and quite a bit more at peak time. Without the need for heating 5kWh is probably enough to cover from 7pm to 2am. So even charging from the grid in summer may work except when solar produces more than the 5kW the inverter maxes out at.
Phil
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Recently installed a PV and battery system. Long story short, it turns out some inverter / smart meter combinations cause the smart meter to read incorrectly. In my case around 100w over what the inverter is actually passing. Seems the particular Landis meter i have is well known in the solar industry to have this issue. Check the Octopus energy site for an article about tesla power walls and Landis meters!
Thanks to this issue i was actually spending more on electricity than before having the solar installed, not at all happy. Called the inverter manufacturer directly, after the ‘what smart meter do you have, oh that one’ conversation they sent me a noise filter that sits in the wire between the inverter and the CU.
This seems to have largely fixed the problem, although i do still get the odd large discrepancy between what the inverter thinks its drawing from the grid and what the smart meter thinks!
A very happy and unexpected side effect of fitting the filter is the hifi sounds better! Lower noise floor. I don’t remember it sounding worst when the solar was installed. But i am convinced it sounds better now!
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https://www.youtube.com/watch?v=B0BNn8AtQDc
This video is about the phantom draw issue where one particular smart meter gets fooled in to thinking the house is drawing from the grid when in fact it is not. The interesting stuff is in the article on the Octopus site (link in the video descriptions) explaining Conducted Emissions. @Simon-in-Suffolk probably knows all about it and it makes you wonder what effect it might have on the HiFi given these emissions are superimposed on the voltage generated by the the solar inverter.
My solar inverter and Zappi are probably 30m away from the HiFi and on a separate distribution board.
Worth a watch.
@Bluesfan was your smart meter of the Landis 100 mm type?
I’ve been on Flux since 7 April. I exported 159kWh and bought 313kWh in April (including 87kWh from 1-6 April). So almost self sufficient using 713kWh according to the Solar Edge App including 128kWh by the Zappi and 279kWh by the Air Source Heat Pump. The panels produced 654kWh DC energy. So the energy doesn’t exactly balance as
713 + 159 = 872 whereas 313 + 654 = 967 or 95kWh to convert 313kWh to DC and 872kWh from Solar and batteries to AC.
95/1185 = 8% assuming both directions have the same efficiency. It a bit lower than they advertise!
Phil
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I’ve just reviewed April’s statistics and am amazed how much better April was to March. For old hands I’m sure this isn’t new news but for a newbie like me having only had solar since mid October it’s still a source of fascination!
We were lucky to be on a fixed tariff but towards the end of last summer our daytime rate increased from 15.5p to 40p, night-time 5.5p to 7.5p per kw so a pretty hefty increase. I was therefore delighted to compare our spend for last April compared to this April. Excluding the standing charge we spent £3 more in the month this year compared to last plus we pushed 55Kw of energy into the hot water via the Eddi which isn’t included in the saving. Our overall monetary saving was £78 for the month so it does look like it will pay for itself quite quickly so we’re very pleased we installed our modest system.
On another mater I’m now obsessed with Home Assistant having done a proof of concept using a virtual machine on the QNAP and now ‘productionised’ it on a Raspberry Pi as the QNAP isn’t generally on 24x7 these days now we have a dedicated Roon Core. It’s a superb piece of software and I love being able to bring all these different pieces of hardware and software into one application. Even my old Owl Intuition ‘smart’ heating can be monitored and controlled by sending data to it via UDP.
I’ve also added a relay board to the Eddi and 2 temperature sensors so I can now measure the top and middle temperature using Eddi and the bottom using the Owl Intuition sensor on the gas heating. Although old the Owl controllers have a digital temperature probe which puts it ahead of many its more modern competitors, allowing different hot water temperaturs within a schedule. Using Home Assistant I can now check the temperatures towards the end of the day and only fire up the gas if the temperatures are insufficient to give us end of day baths/showers due to insufficient heating during the day from solar.
Next we’re going to explore whether we fit a destratification pump to the hot water cylinder to further maximise the solar heating into the immersion heater via the Eddi. It’s a moot point whether it will pay for itself but it does mean we can heat our water almost exclusively for quite a bit of the year without using gas.
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Interesting.
My ‘system’ went in at about the same time as yours.
April 2022 my bill for electricity was £178.
April 2023 my bill is £33.
I’ve also heated all of my water from electricity (about 50kWh off-peak, 64kWh from the diverter). In 2022 the water heating was from my oil fired boiler. We’ve also driven the electric car more.
Overall in April we generated/consumed 494kWh and generated/exported 148kWh (vs 350kWh and 92kWh for March) so it’s certainly stepped up significantly.
Comparing what I consumed overall, and what I paid for it on Octopus Go with what I’d have paid on the ‘standard’ Octopus tariff I’m about £220 in savings this month. Overall I think the system will pay for itself in about 5 years, assuming no unexpected changes in energy prices.
I started this thread over a year ago when I was trying to size the battery I planned to buy. I ended up going with 5.8kWh (the system I have has the battery in 5.8kWh ‘blocks’). On reflection I think I should have gone with 11.6kWh but I’m not sure it would make a massive difference financially. It’s just nice on those days when you’ve ‘generated’ more than you ‘consumed’ (and there were 8 of those in April where my exports were greater than my imports).
I keep meaning to look at Home Assistant but fail to get around to it. One day…
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Our system is about half of yours (2.87 kw) and no battery. I wonder about adding a battery but will wait until we have some more insight.
Our panels are also located on a garage roof with approximately 10 degrees pitch which is less than ideal for winter generation.
We are seeing the benefits of the pitch now as we head into spring/summer. April gave us 297 kw where March was only 150kw.
One odd thing I see is that we get better output on cloudy mornings! The panels are facing south/south west and on a really sunny day there’s an obvious step change as the sun moves round from insignificant amounts of generation to almost maximum output. On the cloudy days the output is much higher earlier. I suppose the cloud is acting as a diffuser?
Our smart meter always shows about 10% more consumption of imported power than the solar app. I asked the provider about this and their answer was that the smart meter was more accurate than the solar app and not to worry about it. Hmm, now I am wondering……
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