Part of Phase 2: First Year
Energy in Phase 2 covers three independent power sources — wind, water, and heat — and the wind-turbine cluster is by far the largest: nine of the eighteen articles here walk through building one, from site assessment to the finished tower. Wind power follows a cube law: doubling wind speed yields eight times the power, which is why a turbine moved to a better spot can outperform a crude one by ten to one, before a single blade gets redesigned.
Site Assessment and Wind Measurement come first — a bicycle speedometer wired to a cup anemometer, set to a 0.33 correction factor, gives a working wind reading before committing weeks to building anything. Blade Design, Blade Materials, and Blade Balancing then shape the rotor: a blade shaped like a ceiling fan captures only 5-10% of the wind passing through it against 35-45% for a proper airfoil, no scavenged material scores well on weight, strength, stiffness, and weather resistance all at once, and static balancing a rotor on a simple pivot eliminates 80-90% of its vibration — the single step that keeps bearings and bolts intact. DIY Wind Turbine covers converting a car alternator into the actual generator, swapping its field coil for neodymium magnets glued on in alternating N-S-N-S polarity. Tower Height, Tower Construction, and Guy Wire Anchors cover what holds the whole thing up: a turbine on a 20-foot pole produces a fraction of what it delivers at 50 feet, since wind speed climbs with altitude and power climbs with its cube, and a 60 mph gust loads a tower with four times the force of a 30 mph one — undersized foundations are the most common failure. Guy wires work in sets of three spaced 120 degrees apart, anchored 60-80% of tower height out, often into a buried deadman set 4 feet down.
Head Measurement, Mill Race and Headgate, Race Construction, Penstock Design, and Riverbed Analysis cover water power. Measured head decides the whole turbine choice: under 3 meters favors a water wheel, 3-30 meters a crossflow turbine, and past 30 meters a Pelton wheel becomes efficient. A mill race channel typically runs 60-90 cm wide with 30-40 cm of water depth, dropping no more than about 1 cm per 5-10 meters of length to stay fast without wasting head to turbulence. Penstock Design is where a mistake gets expensive fast: getting the pipe size and pressure rating wrong costs more than friction losses — in the worst case it means explosive water hammer at the turbine. Riverbed Analysis exists because a pier that looks like it sits on solid gravel can actually rest on a thin veneer over soft material, exactly what probing before design is meant to catch.
Coppicing & Fuel Management, Peat Harvesting, Solar Thermal Collectors, and Heat Storage Systems cover heat and fuel. Coppicing regrows firewood from the same stump for 3-25 years depending on species, the trick that stops a settlement from stripping its forest, and it’s the direct prerequisite for Peat Harvesting, which needs no mining equipment in bog regions like Ireland or Scandinavia — just cutting and drying. Solar Thermal Collectors makes use of the roughly 1,000 watts per square meter the sun delivers at midday, enough for a flat-plate collector built from an old radiator and a window pane. Heat Storage Systems then holds onto that heat: water stores roughly twice the heat of rock per unit volume and moves easily through pipes, while rock and masonry hold mass that also radiates warmth back.
Building a Wind Turbine
Measuring the site, shaping and balancing the blades, and the tower that has to survive a real gust.
- Site Assessment
- Wind Measurement
- Blade Design
- Blade Materials
- Blade Balancing
- DIY Wind Turbine
- Tower Height
- Tower Construction
- Guy Wire Anchors
Water Power
Reading the site’s available head, then building the race and penstock that deliver it to a turbine intact.
Heat and Fuel
Growing and cutting fuel sustainably, collecting the sun’s heat, and holding onto both once they’re captured.