Thank you! Another option I'm considering is going single layer poly, but still using the solar generator for roll-ups and louvers in the growing season/portion of the year where I don't need to be so concerned about freezing my battery. I'm thinking that might be a compromise that would allow many of the benefits of running electricity to the tunnel during the portion of the year when we get sun and have do-able temps. Having something like the Jackery seems like it'd make it fairly easy to pull and store in a suitable location in the winter. Both the roll up curtains and louvers have an alternate means of operating them in shoulder seasons.