A common way of learning more about wind turbines is to build your own with easily available cheap parts. For many years now old Sturmey Archer Dynohubs have been used for this purpose. Available at scrap prices, they generated 3 Watts at 6 Volts – perfect for lighting some LEDs or small bulbs. However as more and more people have caught the wind power bug, these 40 year old hubs have become more and more pricey and difficult to find, and are finally approaching the prices of new modern equivalents.
Retail prices for dynamo hubs typically start at around £30-40 for the most basic model, up well into the hundreds of pounds. However, for use in a small wind turbine generator the cheaper models are perfectly acceptable. The difference in price gets you a lighter weight hub (a disadvantage) and a little less resistance, better weather-proofing, and improved build quality (all advantages).
Bottle Dynamo Wind Turbines
Pictured below is a simple wind turbine generator made using a bottle dynamo.
While these are available cheaply, unfortunately, they do not make very good generators as the voltage output at typical turbine rotation speeds is too low for battery charging, and their power output is very low. A voltage multiplier is therefore recommended with a bottle dynamo in order to get a more useful voltage which is enough for some LED lighting.
Here is a video of a bottle dynamo wind turbine as well as a description of the full system set up:
Alternatives to the Sturmey Archer Dynohub
Here are the details of some alternatives to the Sturmey Archer Dynohub:
Shimano Nexus Dynamo Hubs
The Shimano Nexus range of dynamo hubs is offer a good combination of price and quality. The hub pictured above for example is a typical 6 Volt 3 Watt rated dynamo hub is designed for use as a front wheel hub. Typical retail prices are £40-75 however previous year’s models, shop soiled stock, etc can usually be found for from £20-30. Click here buy Shimano Nexus Dynamo Hub.
Schmidt Dynamo Hub
This Schmidt Dynamo Hub is also another 6 Volt 3 Watt model, however it is the most efficient hub dynamo available (99.77% efficiency claimed). Priced at over £100 retail it is getting very close to the typical price of a Permanent Magnet Alternator made specifically for wind turbine use and with a far higher power output (hundreds of Watts). Therefore you would be very unlikely to invest in this ultra-reliable superbly well-sealed little generator – but if you happen upon one in a few years at a car boot sale or on ebay, snap it up right away!