How to getthe best out of Octopus Flux

Something I've also considered with this is that potentially if you have the option to install more westerley facing panels to favour the 4-7 peak period as this will no doubt always be the peak of the day for electric generation so likely to have higher export rates in future.
 
Alright so I tried to take into account how some solar generation might impact the different tariffs based on todays rates.

Global settings:
  • 0.7kWH per hour house demand on average
  • Daily home consumption of 16.8kWh (24 * 0.7kW)
  • 8.2kWh battery
  • 2.4kW max charge/discharge
Assumptions:
  • Battery is always charged off-peak as far as the max charge rate will allow in the off-peak window
  • Flux battery is held at a certain SOC % until it can discharge some units later on (in my case probably 75% would do).
  • Flux export price for additional exported units is always standard rate not the best peak rate beyond the initial 5.1kWH exported
  • Flux avoids using import in the most expensive peak window
  • Go and Eco7 both just hold the battery at 100% until end of off-peak window, then allow battery to power the home
  • All 3 tariff options first use excess solar to lessen the cost of peak rates, and then export only if that count is met.
  • No accounting for round trip losses still.
The table:

snTmasg.png

Summary:

Once again just highlighting what I already knew. Flux gets better the more you generate. the 20kWh isn't the excess generation beyond usage figure, that is 20kWh generated total. It's also not miles worse even if you only generate a little.

8kWh generation is about the time all 3 start getting very equal, by 10 it's the best option.

Eco7 is actually pretty competitive unless you have an EV or way more battery storage, but lacks the generation payments.

Illustration of how the figures are calculated at 20kWh:

(Regular Cost) - (Peak Units negated) - (Exported Units)

Flux = ([Regular cost] £4.25) - ([Peak Units negated] 12.6 * £0.3423) - ([Exported Units] 7.4 * £0.2439)
£4.25 - £4.313 - £1.804 = £1.87

For Go and Eco7, the Peak Units Negated caps out at the same value as the Imported Peak units (5.8 and 3.7 respectively) and after that all go to export.

Think I'm done with my calc stuff don't want to spend more time on it!
 
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Suggest this modelling needs to be split summer vs winter?
Export levels April-Sept such a contrast to the winter when you’re lucky to export on the average domestic system?
 
Ron-ski said:
@HungryHippos are you able to share your spreadsheet please?
Click to expand...

I'll DM you a link to it :)

Some stuff I've put in formulas, others I've sort of hard-coded, but feel free to take a copy and edit it to improve on it.

SBo said:
Suggest this modelling needs to be split summer vs winter?
Export levels April-Sept such a contrast to the winter when you’re lucky to export on the average domestic system?
Click to expand...

I'm not sure, I kind of took the no solar/worst case scenario figures as the baseline, and considered that any solar generated either a) lowers peak consumption and/or b) allows for additional export, both of which can be calculated separately. So you could work out expected average solar export per day in any given month and it would give you a rough idea.

General idea of charge off-peak, and run the battery flat by the end of the day as well, which is once again into worst case scenario territory.

For me I think Flux will probably lose it's effectiveness somewhere around September sort of time, and will only re-gain it again somewhere around April, so a good 6 months when it makes sense, but I also have to weigh this up against the fact that my Go is at a better rate than the current Go tariff is.
 
Ron-ski said:
Did you do anything, mines still not updated?
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i didnt do anything, but they paid me out my last load of export and it then switched to the flux outgoing.....around 10mins ago

but the export rates are lower than originally stated in the postcode verification on the site.....by a few pence
 
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Welshman said:
i didnt do anything, but they paid me out my last load of export and it then switched to the flux outgoing.....around 10mins ago

but the export rates are lower than originally stated in the postcode verification on the site.....by a few pence
Click to expand...
Are they still higher than the import in the cheap window?
 
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