Soda Stream is advertised as a more sustainable alternative to buying sparkling water in bottles. The main selling points are that no water filled bottles need to be manufactured, transported and recycled anymore.
I am a little skeptical, because the Soda Stream machine itself needs to be manufactured in the first place and producing / maintaining the gas bottles also does not seem zero effort to me.
I do not doubt, that the machines do make sense when used a lot, but are there any data on how many bottles need to be carbonated until the environmental break even (e.g. in CO2) is reached?
I know similar articles about how many ebooks would need to be read on a single ebook reader until its production becomes more sustainable than printing the books on paper instead. For Soda Stream I do however only find articles that deal with which option is cheaper.
I would be interested in comparisons for single use plastic bottles, deposit plastic bottles and deposit glass bottles.