Approx figures for the 20 most abundant elements in Earth's crust:
Notable missing from top 20:
Copper.
Carbon might replace copper for many electrical (and thermal) conduction applications - see [1], [2] and carbon nanotube
for further information. In September 2013, a proof-of-concept computer was built from carbon nanotubes [3]
Figures from [4]
Figures rounded to two decimal places
Also need to have a list based on ease of extraction and energy required
Element links in list point to element's Wikipedia article