How can solar powered sewage treatment plants help municipalities of a developing country ? Does anybody have some case studies or presentation of the said system?

I saw a  video on this subject, I did not find enough details of the solar power plant and the methodology adopted. This is also crucial since the region where such STPs are proposed, regionally they should be amenable for solar power and its utilisation. Does any one has experience of working on solar powered sewage treatment plant? Can you share your experience and some technical details of the system? Do you think this system will be helpful for developing countries like India? Thanks.