out in the open, most likely unattended, for 2+ hours? Balcony comes to mind. But yes, I'd be worried about rain showers. I think the optimal form-factor for

out in the open, most likely unattended, for 2+ hours? Balcony comes to mind. But yes, I'd be worried about rain showers. I think the optimal form-factor for a portable solar charger would be a water-proof, inflatable umbrella (with a stand). Such an umbrella charger could double as sun-shade while you're working and as rain-protection when you leave the laptop out on a table.