An idea of mine that I would like to work on in the future when I have the time and resources is a "Swiss Army knife" style tool to provide some essentials to a small group. The objective is to provide electricity, rainwater collection, potable water, and food preparation/preservation using a system whose parts are not valuable enough individually to be a target of theft. Feel free to use any part of the idea you find interesting or useful. It's an interconnected system, but I'll explain some features separately:<p>Wind Turbine Structure:
Two vertical axis turbines whose blades are hollow (containers) are connected to a circular belt. A tower structure holds the belt in a position such that when the weight ratio of the top turbine vs. the bottom passes a certain threshold, gravity will rotate the belt until the heavier turbine rests at the bottom. The belt will turn a dynamo style generator. While at the bottom, the turbine container will have a plug pressed open and any water inside will drain wherever directed. So on dry and windy days, the turbines will generate electricity. On rainy days, the dynamo will generate electricity while the rainwater is harvested. A great way to store the electricity without an expensive lead-battery is to charge personal electronics or lighting systems (for use at night), and use the rest for refrigeration and ice creation.<p>Solar Radiation Collection:
A semi-spherical lens on top of the wind turbine tower will direct solar radiation inside the hollow tower structure toward a system of lenses and mirrors that focus and collimate light onto the heating element of the Water Distillation structure. The focused ray will be contained within an enclosed structure along its entire path to avoid injury. When the solar radiation is not necessary for water distillation or food preparation, it should be utilized to generate electricity. I don't know the best way to do it without using PV cells or a heat engine with parts that may be too valuable for thieves to resist.<p>Water Distillation/Food Preparation Structure:
The water distillation process will work similar to this image: <a href="http://ep.yimg.com/ty/cdn/solaqua/stilldiag.gif" rel="nofollow">http://ep.yimg.com/ty/cdn/solaqua/stilldiag.gif</a>
However, the solar radiation will not enter from above. Instead the focused ray from the wind turbine tower will heat a metal heating element positioned underneath, but in contact with the dirty water container. The dirty water container will be a u-shaped tower such that a rectangular metal box can be inserted into the the center. At least three sides of the box will be in direct contact with the dirty water container, and the bottom will be near the heating element. The metal box will work like an oven to cook food when the heating element brings the dirty water to boil. Because the structure does not need solar radiation to enter from above, the top of the structure will be a solar food dehydration chamber.