Environment & Energy
Related: About this forumAfricans turn scrap into wind power
Solar power has become the clean energy source du jour for the developing world, and for good reason its relatively inexpensive and many solar panels are robust. But solar panels are often shipped internationally (or at least from distant locations), which makes them less than ideal, especially if a part needs to be fixed or replaced. Access:energy wants to bring a different kind of renewable energy wind power to Kenyans by teaching them to make their own turbines out of scrap metal and car parts.
More than 80 percent of Kenyas population (about 30 million people) lacks access to electricity. The easiest way to get that power to residents is to teach them to make it. So Access:energy a division of the Access:collective, which invests in appropriate technologies for East Africa is teaching local Kenyan technicians to build the Night Heron wind turbine a product that the organization calls the first "commercially viable, zero-import wind turbine."
The turbine generates power at two to three times lower cost than equivalent solar PV panels, can generate enough power for 50 rural homes (about 2.5 kWh per day) and, most importantly, can be built using locally sourced materials. The Night Heron turbines can also be laid out in modular arrays to accommodate growing need.
The uses are virtually endless: allowing people to charge mobile phones from home, giving clinics enough power to keep vaccines cool, providing non-polluting (read: non-kerosene) light for kids who want to study, and providing refrigeration for fishermen.
http://www.futureoftech.msnbc.msn.com/technology/futureoftech/africans-turn-scrap-wind-power-282170
Fumesucker
(45,851 posts)What about the magnets?
Neodymium magnets aren't exactly low-tech and neos are what you need for that style alternator.
And *eleven* coils? I sure would like to see the plans, some multiple of three coils is far more common such as the nine coils on this unit.
drm604
(16,230 posts)I'm not sure what the Night Heron uses, but apparently you can build turbines using ferrite magnets.
http://scoraigwind.co.uk/2011/12/chain-driven-turbine-with-classic-controller
Fumesucker
(45,851 posts)That would make a difference in how much magnet you need for a given voltage at a given blade rpm.
Perhaps the units in the OP are designed for lower voltage..
Notice though that the unit you linked to has 12 coils, a multiple of three.
ETA: Never mind, I found how it's probably wired and it's eleven phase not three phase like all the other alternators of this type I've seen..
It's a variation on this schematic here although each coil probably has its own bridge rectifier instead of one for each pair of coils, else they would have twelve coils.
lumberjack_jeff
(33,224 posts)But because of their shape, results using them are mixed.
Fumesucker
(45,851 posts)I have a few HDs I'm getting ready to harvest the magnets from.
It would take a lot of HDs to have enough magnets to make an alternator that big though