Bourne Energy's BPP-2 puts a 13.6kg, 500-watt generating hydroelectric plant on your back. That's like being able to walk around with 60 solar panels. And when civilisation finally collapses, I'll be dragging mine to an as yet undisclosed location.
You can use the Backpack Power Plant in any stream deeper than 1.2 metres. It also operates silently, with no heat or exhaust emissions, and can be "bottom-mounted" for total invisibility: all good things for hiding from the roving hordes of the post-apocalyptic dystopia. The set-up is pretty straightforward as well:
To install the civilian BPP, you would dig two trenches on opposite sides of a river and insert a lightweight anchor into each. Then, you'd run a synthetic rope between the anchors and the BPP. [The]company designed the system to work like the high-tension mooring systems that hold up floating oil rigs.
There's a military version already in use that can operate in a variety of flow rates, but the $US3,000 civilian edition is designed for streams moving two metres per second. The main target audience is developing countries, where a portable generator of this magnitude could make a huge difference for remote villages and towns.