ConRAD -> you can't seem to grasp the completely scientific efficiency figures I posted earlier. Here they are again:

I never said it does 2.34W @ 20km/h. I don't know where you read that.

You'll find my results are public, this dataset is linked on the website.

Thank you for your "Test it" conclusions, but the D1 is already tested with all 3W dynamo hubs, and with many LED headlights, and with many, many USB devices at different loads.

There's a few on youtube, and more are upcoming.