Great, I hope you will like it. I had bought my cell off of e-bay
E-bay Solar and you may find some better deals. A while back I use to rant about the minimum wattage was 20 watts but as technology moves, so do I if possible. The idea of 35 watt or more can be explained in the videos below but the premise behind having a bigger cell is to run all your electronics 100% without batteries or on cloudy days. It's behind the idea of long term survival that makes life a little more bearable and tries to keep the mind occupied while waiting for rescue or what have you. Also look at what your solar needs may be and a bigger cell my be a good investment in the long run, it just depends on what your goal is. Good Luck.
These Videos are old and boring but it drives the point across that a good solar cell can give you:
1. Shelter
2. Water Purification
3. Fire
4. Communications
5. Navigation
6. Possible food if you use a laser pointer and run fish into a trap in a clear lake
7. Electronic maps or aid in supplying power to laptops
8. Light (charging batteries for lights, etc,,)
9. Any many more that you can think of.
See Videos
Video 1
1 Video 2
2 Video 3
3 Video 4
4 Video 5
5