Porcupines' quills, or spines, take on various forms, depending on the species, but all are modified hairs coated with thick plates of keratin, and embedded in the skin musculature.
Produce up to 400-Watt of power for free in your own back yard. The wind turbine will produce more power up to 400-Watts at 28 mph. If the wind dies down the turbine will continue to produce power in winds as low as 5.6 mph. This wind generator is used to charge 12-Volt batteries and mounts on any 1.5 in. Schedule 40 pipe.
At the optimum wind speed of 25-35 mph, the blades will rotate at 14 rpm. That gives them a speed of 105 mph at the tip. How much electricity do they produce? Each turbine produces about 2,000,000 kilowatt hours (kwh) per year, enough energy to power as many as 500 typical homes at 12,000 kwh per year.How strong do the winds have to blow for the blades to rotate? Wind turbines start operating at wind speeds of around 8 mph and reach a maximum power output at around 33 mph.When there is not enough wind to turn the blades, or when there is too much wind the turbines shut down.ow strong do the winds have to blow for the blades to rotate? Wind turbines start operating at wind speeds of around 8 mph and reach a maximum power output at around 33 mph. When there is not enough wind to turn the blades, or when there is too much wind the turbines shut down.