Electric Motor Windings

• Aluminum windings DO compare well to copper windings based on resistivity and density considerations.
• See resistivity - [1] - aluminum is under 2x more resistive than copper.
• But aluminum density is 2.7 g/cm3 - whereas copper is 9 g/cm3. Thus, >3x as heavy in its density. This means that the weight of windings will actually be lighter for the same current flowing through the winding. Which means that a motor of the same power is likely to be lighter (though larger in size) - unless the non-winding parts of the motor are all together heavier because of the larger volume of the motor.
• The relevance for the GVCS is eliminating the need for copper if aluminum from clay is acceptable - such that an electrical power economy can likewise be produce without strategic resources such as copper.
• This article verify that aluminum-wound electric motors are feasible - [2]
• Aluminum carries 2x the current per pound compared to copper, and is 1/2 to 1/4 the cost - making aluminum windings 4-8 times less expensive than copper windings - [3]
• Aluminum may have more skin effect, and be less efficient for certain high efficiency applications. [4]
• Heat storage capacity of aluminum is 2x as large, so aluminum can withstand larger overlaod conditions - [5]
• Cost breakdown of transformers indicates ~20% for the windings, ~35% for magnetic steel. -[6]