10-year interest-free loans for SBSP (was SBSP at 80 cents per watt?

> When you are cranking out a 5 GW power plant in a week, you can ignore financing and inflation.

You said it was a 10-year payback period:

80 cents/watt installed cost
8 cents/watt-year revenue (1 cent per kWh; 8 kWh/year production)

That implies at least a 10-year loan. Wouldn't it be reasonable to assume that there would be interest charged on a 10-year loan?