Strandbeest and low cost primative energy accumulators

http://www.strandbeest.com/beests_storage.php

I could enjoy playing with something like this. The next level is to add some primitive sensors and directionality to the beast so it can sense the wind and direct itself into the wind in such a way as to optimize its energy input.

Then give it a sense of energy conservation, so it can evaluate its own energy stores and decide to conserve energy when the wind ( energy source ) is low.

This is an interesting example of very low tech energy accumulators. It uses air pressure and polycarbonate bottles as the pressure vessels. All you need is a pump, pipes and some valves and you have a cheap, maintainable and accessible energy system. Its low power and low availability but simple enough to set up anywhere there is wind.

Once you have some sort of turbine or other converter you could hook all sorts of wind sources ( steam, vapor, waste air pressure etc) into the same system.

Building a low efficiency turbine using similar materials and some sort of magnets and induction coils should be fairly straight forward. The materials are getting a little more exotic however. (Copper wire and some magnets) but still fairly easily scrounged from any stream of modern waste.
If you have access to old electric motors then you are already there, just run it backwards. So you have the ability to harvest wind energy, store it and deploy on demand.

Now we just need a big enough bottle farm to hold all the accumulated energy without leaking.

I remember seeing a low tech bio-gas pressure system made from two water tanks, one large open topped one ( which could be replaced by a simple dam or large puddle) and half filled with water to form the seal. The second tank was upside down and held the gas. The gas was pumped into the tank under low pressure and the tank rose. Then they simply added some bricks and rocks to the top of the tank to increase the pressure and thus had a high pressure source of bio-gas to run the stove.

You could do something similar with this kind of rig.  Just use the wind power to pump air at low pressure into vessels then change the pressure by adding something easy ( say water ) which can be pumped around to add weight to the vessel.  Then you have a high pressure air source to generate power on demand.  The stored potential energy can act as a large, simple battery.