On the other hand, domestic oil production has taken a jump in recent years due to fracking, tar sands, deepwater drilling, etc., but oil and other fuels obtained from those sources are actually more expensive and take more energy to get than oil obtained from conventional wells. This is what’s called the EROEI ratio, which stands for “Energy Returned On Energy Invested.” According to data compiled by professor L. David Roper, in the early 20th century, the golden age of North American oil production, the equivalent of one barrel of oil invested yielded as many as 100-200 barrels produced. By 1970, the average EROEI ratio for crude oil had fallen to 30:1 (Saudi oil fields are still producing at this rate). Today, one barrel of oil invested typically gives only 15 barrels in return. New technologies, such as tar sands, have a barely 2:1 ration of energy return on […]