Lesson 59: Drilling for Natural Gas
In this lesson, we will discuss natural gas as an energy source, and
also look at the concept of EROI, or Energy Return on Investment,
to evaluate energy sources.
The United States has a large reserve of natural gas that
could fuel the economy for 45 years at the current rate.
Many techniques have been developed to
drill for underground natural gas including fracking.
Fracking is the process where natural gas trapped in local shale deposits can
be pulled out by fracturing the shale and releasing the gas into spaces propped
open by sand. However, there are problems with fracking as chemicals used in
the holding ponds of water (where the gas is held upon release) can leak into
groundwater.
Natural gas is being used in residential and commercial heating.
EROI is the ratio of energy returned to energy captured.
A high EROI is a great return on investment.
Initially, US oil exploitation had a high EROI but after dependence on foreign
oil, has become less so. Currently, domestic oil, followed by coal,
hydroelectric, imported oil and firewood have the highest EROI. Renewable
energy has a lower efficiency rate and lower EROI.
For renewable energy to be a reliable source of energy,
it has to be more efficient and effective with a higher EROI.