what is project NPV?

Duluth Snow Removal Co. is considering purchasing an $825,000 snow melting machine in order to get a contract with the city. They have estimated that the machine would only last four years at which time it would be scrapped for $60,000. It will be depreciated using MACRS and it falls into the 5-year schedule. The 4-year project will generate $480,000 in annual revenue and $95,000 in annual costs. The project will require an investment of $20,000 in net working capital. Duluth Snow is in the 20 percent tax bracket and requires a 17 percent return on projects