Possible Clues:

• Handy American fuel produced
• Convenient American energy extracted from coal, say, and sent North
• Worthwhile American English teaching outside of university
• Fuse blown at centre of bulb — that's handy
• Universal fuels designed to be beneficial
• Handy American fuel supply
• Lead in unleaded fuel's unusually handy!
• Good for something
• It's handy for us to have fuel like this
• Advantageous American fuel supply