Energi's insurance products are designed for the energy sector. I do not know whether their policies offer discounts for brokers or producers who incorporate biofuel into fuel cycles. It's worth a look if insuring a biofuel feedstock takes some risk out of crop failures. Project finance for biofuel might be more difficult. Joule Assets finances efficiency projects, and I believe a comparable model could cover biofuel projects tied to facilities like grid sector fuel cells (yes, such things are more than just drawing board dreams).
The Joint BioEnergy Institute (JBEI) underwrites some tech development with help from major labs. The whole DOE Bioenergy Research Center effort touts the numerical output of patents filed but I don't readily see numbers for commercialized success stories. If biofuel incubation is another process-oriented bureaucratic runaround it will turn off results-oriented entrepreneurs. I hope these centers implement the NSF Innovation Corps standards or they'll have a hard time getting respect from VCs. Meanwhile, someone with less patience could take a biofuel idea from the US DOE Algae Testbed Public-Private Partnership (ATP3) and run it through the Carbon War Room to see if anyone in the ecosystem endorses it.
The phrase "attention capital" is not so new. It dates to design articles from the last decade and beyond. The important thing is that startups draw attention to themselves early enough to gather buzz. Leveraging the biofuel ecosystem is one way for startups to get that buzz.