You need to incentivize to energize. Your incentive structure has to stimulate the right triggers. Quick wins are among the strongest triggers for the group, providing instant proof of success. This, in turn, induces feelings of ownership as well as commitment.
Learning new competencies or acquiring knowledge are great incentives for team members to work on the cross-industry innovation project. Actively use these as energizers for the team.
Your incentive and accountability system should be outcome-oriented. Choose triggers that can be measured and that contribute to group cohesion. You'll have a hard time forecasting profit from radical innovations at an early stage. Use non-economic triggers instead.
Energizing also means communicating. It is crucial set up a proper communication structure. The innovators within the partner organizations should be able to connect and to exchange tacit knowledge. Generate success through an ongoing practice of regular meetings among major subgroups of key stakeholders.
Though often neglected, informal communication is as important as formal communication. From time to time, try and use channels that are outside the focal project for meetings and conversations between stakeholders of the project. Developing such informal communication networks will definitely increase the energy of the team and keep the momentum going.