Is that just the website? Is there a way to export the raw data?

+1 yes we need a way to export and analyze data to get the insights we want. Would be great if we can share through Datasette which is tailor made for such applications

there's an export button at the bottom of the table which copies a CSV to your clipboard.

The heatpump performance data looks crowd sourced. If the website and DB are run with open source software, that's a different thing and seems secondary.