While the rain continues to stop play for Solar Impulse in Paris, I've been on board the Boeing 747-8 Freighter that flew from Seattle to Le Bourget powered partly by camelina-derived biofuel.
I chatted to one of the landmark flight's pilots, Capt Nick Braun, who described the flight as a "non-event".
I was hoping for a more exciting quote but I guess the fact that the flight went like any other flight is a good thing. Still though, a bit of enthusiasm wouldn't have gone amiss.
Before this I spent some time with algae biofuel producer Sapphire Energy, which aims to produce commercial levels of sustainable jet fuel by 2018.
They've got lots of US government backing and bags of enthusiasm, so hopefully this prediction will ring truer than the more cynical "algae fuels are at least 10 years away" line that you hear from other quarters.
All in all it's been a pretty green day, including my bright green dress, which has prompted jokes from my colleagues that I've come to the show dressed as algae. Always nice to be told that you resemble a big lump of green slime.