So they are saying the project has a 40 year pay back when the system will only last 10-20 years.  I've been involved in many energy
saving projects and very few ever save money.  When you add in maintenance and labor costs most lose money.  Projects were never considered 
if they didn't have a pay back of 2 years or less so please don't pass this off as a cost saving for the school district...it won't be.
Grants are never based on reality.