[Elecraft] Solar Panels

[Douglas Todd]

I'm interested in using solar panels to power the K2 for emergency/field day operations and am wondering what sort of experience others have had.  The panels seem expensive: about $100 for a 5 watt panel  but with battery and a low power draw of the K2, they  look like they can sustain operations for extended periods of time.

How does this work in practice ? Is there enough 'juice' delivered to keep a station operational ? How about portability ? 

Thanks to everyone in advance for your responses.

Douglas Todd (KE7GYQ)