The effect of alternative energy

• Who are the other users affected?  How are they affected?
• Is this joint supply or competitive supply?  Do you know why?

AS Economics Metals from copper to silver hit record highs

Metals prices on the London Metal Exchange have risen in the last month.  Can you split the demand and supply factors?

• Why should a strong Yen see Japan buy more metal?
• What is the significance of "oil traded in the region ...$94 per barrel in London for the fifth day in a row ... the commodity could top $100 per barrel in the new year"?
• What do you think is the PED and PES for oil?
• How does this contribute to commodity markets often being volatile?

What influence does the price of Sterling have:

http://www.bbc.co.uk/news/business/market_data/currency/11/12/twelve_month.stm
http://www.bbc.co.uk/news/business/market_data/currency/13/11/default.stm

Video on Joint demand and derived demand

Excellent explanation here. 

Examples are critical to taking your understanding forward.