Grant Thornton is a well known CPA firm. For about 100k, they should be able to perform a review of the technology to render an opinion if the CLNV process would be able to qualify as a green bond.
Green bonds generally have a lower yield for the same duration and quality. CLNV would likely be an unrated bond. Even if a shadow rating were determined, it would not be investment grade. Likely a single B at best but more than likely a higher C rating. This places a green bond issue at a 9 percent minimum.
If a green bond is issued and there is some future issue with qualifying for a green status or monetizing any credits, many bonds have a rate adjustment provision in the indenture.
Getting a green bond takes a little longer than a conventional bond even with a big name firm behind you. I am working on two exchange traded green bonds now. Not overly complicated but it is a longer process.