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.
After the Volga River, the Danube River is the second largest river in Europe. The Danube River is 2900 km long with a drainage area of 817 000 km 2. The Danube Riverâs source lies in Central Europe, on the eastern slopes of Schwarzwald, at 678 m above sea level. The river flows into the Black Sea along the boundary between the Ukraine and Romania. In its lower reaches, the river is 1 to 2 km wide. The Danube forms an extensive swampy delta (4500 km 2) that is restricted by dams and natural beach ridges.