Very good point, I have a couple of those hand cranks around the house and the amount of light for the cranking never seems worth it. I am definitely behind you in letting the sun do the work, investing into the portable 40 watt solar cell by far was the best investment I've made in quite awhile. It's like having a little power station where I go, except those really cloudy days. I definitely think this one isn't worth the effort to convert to portable due to the way it is set up using plastic bottles and very poor gear ratio to where you have to crank really fast and a long time with those results. I just stick with the cells.