Complex sentence: The energy crisis of 2005 refers to the marked rise in the price of oil, gasoline, and other energy prices triggered when Hurricane Katrina substantially impacted refinery and distribution capacity during the beginning of September 2005.
Split into simpler sentences: The energy crisis of 2005 refers to the marked rise in the price of oil, gasoline, and other energy prices. This was triggered when Hurricane Katrina substantially impacted refinery and distribution capacity during the beginning of September 2005.