Frankly, I don't think that a solar arrangement will save any money. The advantage that solar gives is range; however, you cannot plan on high speeds using solar, by itself, on long trips.
As you can see from the thread below this one. Going solar is pretty involved. I realize that the panels I went with are a compromise. I wanted light weight panels so as to not be too top heavy. However the result is that I am only going to get about 100W/sq meter. The metal is still on order; so the project is nowhere near complete.