Power of Attorney for Gevo, Inc. Officer

This filing details a Power of Attorney granted by David Kettner, General Counsel of Gevo, Inc., to Edwin Cabell Massey and others. The attorneys-in-fact are authorized to act on Kettner's behalf concerning SEC filings, including executing and submitting Forms 3, 4, 5, Schedules 13D and 13G, and Forms 144. They are empowered to manage Kettner's EDGAR account, obtain information on Company equity transactions, and perform all necessary actions related to these filings. The Power of Attorney remains in effect until Kettner is no longer required to file these documents or until it is revoked. Kettner acknowledges that this does not relieve him of his personal responsibility for compliance with securities laws.