Interesting stuff from Low Tech Magazine

How much energy does it take (on average) to produce 1 kilogram of the following materials?

•Wood (from standing timber): 3-7MJ (830 to 1,950 watt-hours).
•Steel (from recycled steel): 6-15MJ (1,665 to 4,170 watt-hours).
•Aluminum (from 100 % recycled aluminum): 11.35-17MJ (3,150 to 4,750 watt-hours)
•Iron (from iron ore): 20-25MJ (5,550 to 6,950 watt-hours)
•Glass (from sand, etcetera): 18-35MJ (5,000 to 9,700 watt-hours)
•Steel (from iron): 20-50MJ (5,550 to 13,900 watt-hours)
•Paper (from standing timber): 25-50MJ (6,950 to 13,900 watt-hours)
•Plastics (from crude oil): 62-108MJ (17,200 to 31,950 watt-hours)
•Copper (from sulfide ore): 60-125MJ (16,600 to 34,700 watt-hours)
•Aluminum (from a typical mix of 80% virgin and 20% recycled aluminum): 219 MJ (60,800 watt-hours)
•Silicon (from silica): 230-235MJ (63,900 to 65,300 watt-hours)
•Nickel (from ore concentrate): 230-270MJ (63,900 to 75,000 watt-hours)
•Aluminum (from bauxite): 227-342MJ (63,000 to 95,000 watt-hours)
•Titanium (from ore concentrate): 900-940MJ (250,000 to 261,000 watt-hours)
•Electronic grade silicon (CVD process): 7,590-7,755MJ (2,108,700 to 2,154,900 watt-hours).

Note: 1 megajoule (MJ) = 277.77 watt-hour (Wh)