I can't find a similar request elsewhere, my apologies if this has been asked before.
I'm considering moving to Octopus but first I'd like to analyse my daily/hourly useage. Is there a way to download all my daily logs other than one at a time - all 365 of them!
download year's worth of data?

If you use the Energy Graph (Legacy) on the portal it gives you the option of a yearly report which is downloadable as a .csv file. You can also modify the date range by clicking on the date.
The non-legacy energy graph probably has the same, but I've found that gives different figures (!) so I don't use it. The legacy version figures are very close to the actual consumption figures produced by Octopus...
mwilliams2 see https://community.givenergy.cloud/d/2881-report-data-download-as-excel-file
Powershell scripts to download the data from the GivEnergy portal API.
I’ve successfully downloaded months and months of data using the script (in my case for reloading into Home Assistant)
I used about 12 months of the data to successfully take Octo to the Ombudsman and get them to fix my smart meter after 4 years. (Not actually Octo's fault, but the DCC, however I cannot complain to the DCC)
geoffreycoan many thanks for that. I'll have a go shortly.
M.