Stadtwerke + Sparkasse: Savings bond for local wind turbine - 10 years, 3.4% pa - makes sense?

Some new wind turbines are being built in our area. Jointly by the municipal utilities and BMR energy Solutions GmbH. As residents, we could purchase a savings bond between EUR 1-10k with 3.4% pa over 10 years. I haven't seen any details yet, only the information that it is a public participation process with national deposit insurance and therefore no risk. You can get further details from a consultation at the savings bank (bah...) Before I do that to myself, I wanted to