Joining the Renewable Heating Hub forums is completely free and only takes a minute. By registering you’ll be able to ask questions, join discussions, follow topics you’re interested in, bookmark useful threads and receive notifications when someone replies. When choosing your username, please note that it cannot be changed later, so we recommend avoiding brand or product names. Before registering, please take a moment to read the Forum Rules & Terms of Use so we can keep the community helpful, respectful and informative for everyone. Thanks for joining!
Agile: average import cost vs other tariffs?
@toodles Thank you for sharing that. I note you have a small amount of consumption at peak rate (7.1kWh). Were you expecting that, or is that Octopus doing funny things with your battery?
The reason I ask is I noted on a YouTube channel a reviewer observed that Octopus would never discharge their battery fully down to 20% during the peak, but would stop the discharge at ~24-25% and then they would end up importing a small amount at peak rate for the last 15mins or so (18:45-19:00), even though there was spare battery capacity. I wonder if you are seeing similar behaviour?
Samsung 12kW gen6 ASHP with 50L volumiser and all new large radiators. 7.2kWp solar (south facing), Tesla PW3 (13.5kW)
Solar generation completely offsets ASHP usage annually. We no longer burn ~1600L of kerosene annually.
@old_scientist I have been imitating a hawk towards the point when the Powerwall remaining capacity nears 20%; on the first few days, there was some overshoot and ‘Constantine’ in his octopus wisdom started to recharge the battery during peak time.
During subsequent days, this has improved as the algorithms learn my system’s capacity and likely solar contribution. Today, I don’t think there was any overrun at all.
What happens is that when it reaches 20%, the discharge from battery ceases and it just takes any remaining available solar. If and when the solar no longer provides as much as the house demand requires, the system will just take enough from the grid to keep things ticking over until 19:00 when we return to the standard rate again. I find that Constantine usually starts to recharge at 23:00 and by the morning, I may have 50-60% (sometimes more) charge awaiting use. Solar then tops this up so that when we reach 16:00, we have 20+ kWh to export to the grid plus ‘real time’ solar on top. Long before this, the battery is usually full and excess solar is being exported at the standard rate (still higher than the Outgoing Fixed Export rate). At such times, the system is exporting to the grid at ~14kW for the first hour or so then tapers a little. I will report in greater detail (and confidence!) next month when I have a full month’s results to work with. Regards, Scrooge err… I mean Toodles.
Toodles, heats his home with cold draughts and cooks food with magnets.
@toodles thanks for the analysis. I'll be really interested to hear how well Octopus manage the charging and discharging of the battery once things settle down and you have a little more data. Trying to predict how much to discharge during the peak rate slot, and still leave you enough charge to run the house must be difficult, especially if some evenings one decides to turn the oven on at 6pm and on other evenings you're outside grilling on the BBQ with excess solar. Maybe in the height of summer it's less of an issue as solar will be stronger for longer, so house load at the end of the peak period is more likely to be covered by solar and less dependant on battery (although my electric oven still pulls 2.7kWh so we'd have a 3kW base load).
It would be nice if Octopus allowed export down to 20% and then house load only down to 10% to give a little in reserve to cover house load if required.
Samsung 12kW gen6 ASHP with 50L volumiser and all new large radiators. 7.2kWp solar (south facing), Tesla PW3 (13.5kW)
Solar generation completely offsets ASHP usage annually. We no longer burn ~1600L of kerosene annually.
@old_scientist I have written to OE on the subject of discharging to grid down to 20% then allowing house load to use battery down to perhaps 10% - I don’t see the point of using the grid during peak demand time (and subsequent higher rate for consumption too during the last half hour or so of the ‘spensive block).
Rather than formulate my feelings on using IOF with just experience of one month, I’ll wait for a further month; there were some heat pump on days in April despite the sunny days. The heat pump is less likely to be used in May and may provide a more meaningful example to base my typical consumption and solar production on. I’ll report back in in early June if I may. Regards, Toodles the Scrooge.
Toodles, heats his home with cold draughts and cooks food with magnets.
Posted by: @toodles@old_scientist I have written to OE on the subject of discharging to grid down to 20% then allowing house load to use battery down to perhaps 10%
Thank you - I await your update 😀
Our average import rate on Agile for April was 15.4p. The first half of the month saw no heating, with a little heating in week 3, and the last few days again with no heating requirements as temperatures soured. We are still awaiting the outcome of our G99 application for a PW3 which has been over 2 months now. We may or may not get things sorted in time to switch to IOF this summer.
Samsung 12kW gen6 ASHP with 50L volumiser and all new large radiators. 7.2kWp solar (south facing), Tesla PW3 (13.5kW)
Solar generation completely offsets ASHP usage annually. We no longer burn ~1600L of kerosene annually.
@old_scientist We are with SSEN and our G99 application took over 12 weeks then in 2022.🤨
Toodles, heats his home with cold draughts and cooks food with magnets.
-
Who's your electricity provider and what's your tariff?
2 days ago
-
EV+ Heat Pump Tarriff
3 months ago
-
Our journey through Octopus tariffs 2020-2025
3 months ago
-
Confusion over Octopus Tariffs
4 months ago
-
Outcome for 2024 - with Agile, ASHP, PV, Batteries, EV
1 year ago
Currently viewing this topic 2 guests.
- 27 Forums
- 2,541 Topics
- 59.2 K Posts
- 1,986 Online
- 6,822 Members
Join Us!
Worth Watching
Latest Posts
-
The UFH system was installed at the same time as the GS...
By phowardstutterheim , 2 minutes ago
-
RE: Heat pump Surge protection
@transparent Many thanks for the advice and I will cert...
By DavidAlgarve , 15 minutes ago
-
RE: Aerotherm 12+12kw cascade huge power utilisation
@editor This is really crazy. I can sort of understan...
By JamesPa , 7 hours ago
-
Or just add any further discussion to the other thread....
By cathodeRay , 7 hours ago
-
RE: NIBE Heat Pump Warranty: What's an Adequate Engineer Attendance Time?
@hughmark, great to hear. Fingers crossed that it’s sor...
By Mars , 18 hours ago
-
RE: Daikin high temperature heat pump
I’ll check in with Daikin to see if they can help answe...
By Mars , 18 hours ago
-
RE: Samsung Gen 7 16kW Integrated unit Modbus monitoring
@johnnyb HI,I have an integrated unit with all componen...
By antonical , 20 hours ago
-
RE: Solar Power Output – Let’s Compare Generation Figures
@papahuhu Ironical isn’t it? The last few days, the ‘Ag...
By Toodles , 22 hours ago
-
RE: Setback savings - fact or fiction?
I answered that days back, I even provided a summary of...
By RobS , 22 hours ago
-
RE: If a heat pump can only heat DHW to 50C then what? Issue with 18KW Heliotherm heat pump
I must say that this install is sounding more and more ...
By Mars , 1 day ago
-
RE: Who's your electricity provider and what's your tariff?
@chandykris Thanks, that’s a fair point and I agree th...
By Eliuccio , 2 days ago
-
-
RE: The law of unintended consequences....
Oh Thank you Major, I was just beginning to wonder wher...
By Toodles , 3 days ago
-
RE: Forum updates, announcements & issues
I know that the notifications are being delivered now w...
By Mars , 3 days ago
-
RE: Advice needed after a successful "leftfield" experiment.....
@pauli I have sent a direct message with the financial ...
By ChandyKris , 3 days ago
-
RE: Octopus Cosy 12 Heat Pump Regret: Incredibly Loud, Poor Heating & Constant Hum - Help!
Does it disappear when the heat pump is off? What abou...
By JamesPa , 3 days ago
-
RE: Fitting heat pump plumbing and pipes in advance?
Great tips, thanks. The PEX/Al/PEX option sounds much m...
By Jonatan , 3 days ago
-
RE: Struggling to get CoP above 3 with 6 kw Ecodan ASHP
Those control valves on the UFH manifold could be an is...
By Travellingwave , 3 days ago
-
RE: Daikin Altherma 3 LT compressor longevity question
Up to a point yes. However every heat pump (and every ...
By JamesPa , 4 days ago
-
RE: New Build ASHP Defects - Looking for Advice, Support & Shared Experiences
Is that a single pair only? If so it may be part if th...
By JamesPa , 4 days ago
-
@batpred, you’re quite right; it does work well. I don’...
By Majordennisbloodnok , 4 days ago
-
RE: Ecodan Cylinder Possible Weeping Around Thermostat Port
Update: Mitsubishi sent an engineer around. It was li...
By Gruff2001 , 4 days ago
-
RE: A Smarter Smart Controller from Homely?
@benson Agreed. I believe the COP gains with homely, i...
By Papahuhu , 4 days ago
-
How to Find All Your Posts and Topics on the Forum – A Quick Guide
If you’ve ever posted something on the forum and then s...
By Mars , 4 days ago


