The article is about a school district. They say they'll save $1M per year and the grant would br around $1M. It seems they have plenty of financial reason to put in solar and they could easily finance that million. This is very much about them wanting the free grant money.
School districts are government funded... so its really just which arm of the gov is footing the bill. Its all government money no matter how you cut it.
School districts in Pennsylvania are their own government systems under the state, similar to municipalities. They get money from the state, but a lot of their budget comes from real estate taxes. The subsidies are a way to guarantee the money is used by the districts for a specific purpose.
Subsidies are just an indirect way of paying someone to do something. Its no more free money then if you like your job, your job is free money.
Its true though, if demand is high it probably means you are overpaying and could get the wanted result while paying less.