Kilowatt-Hour per Unit of Fuel. The energy value of a unit of fuel depends on its mass, carbon and hydrogen content, and the ratio of carbon to hydrogen. In general, hydrogen generates approximately 62,000 BTU per pound and carbon generates around 14,500 BTUs per pound.
Quick Answer. The three largest rivers in Portugal are the Tagus River, the Douro River and the Guadiana River. All three rivers also flow through Spain. The largest river in Portugal is the Tagus River; it is 645 miles long. Continue Reading.
Lisbon is one of the oldest cities in Europe -- older than London and Paris -- and its position at the intersection of the Tagus River and the Atlantic Ocean made Lisbon the jumping off point for many 15 th-century Portuguese explorers, including Vasco da Gama during the cityâs golden age.odern Lisbon is suffused with the memories of past centuries that emanate from the cobblestone streets and crenellated castle walls.