In my August 14, 2015, "A Quick Run Around the Web," I had linked to an article from U.S. Crow entitled "How and why you should be a Data Prepper." Someone made comments to my post that I just wanted to emphasize (because I know that people don't always read the comments):
The Data Prepper had some good ideas - like having physical copies of core reading/reference materials. However, he seems to fall into the frequent trap of thinking that a laptop computer and some solar panels will allow him to access digital materials over the long-term.
I frequently read about people who plan on putting the bulk of their survival/prepping library on an electronic device - laptop computer, tablet computer, or an e-reader like a Kindle. The problem with these devices is that they are not designed with long-life in mind and are rather fragile. They all utilize rechargeable batteries (most likely lithium-ion cells) that will eventually fail (in my experience, typically two to four years for devices used regularly).
Personally, I don't have a long-term digital survival/prepping library plan because I believe keeping a laptop/tablet/e-reader operational long-term will be challenging. Instead, I will rely on physical books. That said, I regularly back up my collection of digital materials to USB flash drives and external hard drives.
I think a 2 TB external hard drive is overkill. In contrast, a 32 GB USB flash drive is probably adequate, and they are cheap. I would probably opt for redundancy and duplicate the data on several name-brand flash drives incorporating flash memory chips manufactured by different manufacturers. Further, I think I'd put a core collection of digital materials on CDROMs or DVDs to provide more options for reading the data with an unknown future computer.
As I ponder long-term access to a computer, I think having the practical skills to cobble together a computer from salvaged computer parts would be a valuable skill to have. (This skill is developed by building, repairing, and upgrading desktop computers. In addition to the hardware skills, develop a working knowledge of how to install popular distributions of Linux on a PC.) I would expect that finding electricity to power a desktop PC will not be a lot more difficult than finding electricity for a laptop computer.
An alternative long-term computer solution might be the small Raspberry Pi 2 single-board computer - don't be fooled by its diminutive size. It only needs an external 5 VDC power source, a USB keyboard and a TV/monitor with an HDMI input. (The Raspberry Pi 2 also has a composite video output, but I have not tried to hook it up to a composite monitor.) The Raspberry Pi 2 runs a flavor of Linux from a micro-SD card. As an added benefit, Raspberry Pi computers are cheap.