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.
It forms a short section of the Moldova/Ukraine border in the northeast, flows into Moldova, then borders Ukraine again in the southeast. It finally reenters Ukraine in the south shortly before emptying into the Black Sea. The second-longest river is the Prut, a major tributary of the Danube River. The Prut River forms Moldova's entire border with Romania before flowing south into the Danube. Like the Nistru, the Prut originates in the Carpathian Mountains in southwestern Ukraine; it flows a total distance of 909 kilometers (564 miles).