(1) To provide greater accuracy in comparing fuels, energy content is measured in terms of "British Thermal Units (BTU's)."

(2) That land receives more than 4, 500 quadrillion British thermal units (Btu) of solar energy a year.

(3) In the United States, heat is measured in British thermal units (Btu).

(4) On Tuesday, natural gas futures rallied for a third day, gaining 1.2% in the New York Mercantile Exchange to $3.959 a million British thermal units.

(5) Natural gas for April delivery rose 1.8% to $4.244 per million British thermal units in the first four days of trading this week in New York.

(6) At current low prices of less than $5 per million British thermal units, natural gas doesn't need subsidies to encourage utilities to switch from coal or oil to gas for generating power.

(7) A study published in this month's issue of the journal Environmental Science and Technology found out: roughly 350 million barrels of oil, or more than 2 quadrillion British thermal units of energy.