Man powers his home from local stream with DIY micro-hydro plant. A man named Manfred Mornhinweg found the modern world too "noisy and hectic", so he decided to build himself a house on a quiet 40 hectare piece of land in Chile.

Part of his project involved building a micro-hydro plant to generate electricity for his dream home, and he documented the DIY adventure on his (very old-school) website. I found it interesting, and though that you might enjoy it too.
Gradient, Slope, Grade, Pitch, Rise Over Run Ratio Calculator. Bicyclists, motorists, carpenters, roofers and others either need to calculate slope or at least must have some understanding of it.

Slope, tilt or inclination can be expressed in three ways: 1) As a ratio of the rise to the run (for example 1 in 20) 2) As an angle (almost always in degrees) 3) As a percentage called the "grade" which is the (rise ÷ run) * 100. Of these 3 ways, slope is expressed as a ratio or a grade much more often than an actual angle and here's the reason why. Stating a ratio such as 1 in 20 tells you immediately that for every 20 horizontal units traveled, your altitude increases 1 unit.

Stating this as a percentage, whatever horizontal distance you travel, your altitude increases by 5% of that distance.
Taco-Hvac. Electro-mechanical thermostats have a small variable heater built into them.

It tricks the thermostat into thinking that the room temperature is satisfied so the temperature doesn’t overshoot. The setting of the heat anticipator is based on the current draw of the connected zone valve wiring.
Earthbag Construction. EarthBag Homes - you're standing on the building materials... earthbag home Long sandbags are filled on-site and arranged in layers or as compressed coils.

Stabilizers such as cement, lime, or sodium carbonate may be added to an ideal mix of 70% sand, 30% clay.

Green

Superb Idea: A Transparent Drain - Design. Construction Management.