The weather this spring has been so erratic, one never knows if it's safe to plant those summer plants that are susceptible to frost. We finally set out our vulnerable peppers and tomatoes, only to learn it's supposed to hit the 30s Thursday night. On the bright side, it's always a good time to take advantage of a sunny day to make granola.
While this can be done in the oven, using the sun's heat is more environmentally friendly. We build a solar dehydrator, which works great as a low-temp oven for baking granola and granola bars. You could easily stick a cookie sheet in your car as well, which is not only "green", but also clearly the most inexpensive option; and some folks find that ingenuity irresistable.