by Rex Trulove

Created on: August 07, 2010

Many places are blessed by geothermal energy. Iceland is one such area. Another is the Pacific Northwest. There are legitimate environmental concerns with geothermal heat, however.

Geothermal energy is nearly always heat caused by water that has gotten near a volcanic magma pocket, such as those often found in the Cascade Mountains. This is naturally occurring, and it results in water being turned into steam, which can be used in a number of ways for energy. It can be used directly for heat, or it can drive turbines to create electricity, for instance.

This usually requires the hot water to be pumped out of the ground for whatever use it is destined for. This is the biggest environmental concern, probably.

A water table contains a finite amount of water. It is replenished, but normally not rapidly. Pumping water out of the water table lowers the amount of water available to be heated for geothermal energy. This isn't great for the environment, and can lead to an unstable system.

This is a concern that can be easily addressed. If there is a pipe pumping the hot water out, another pipe should be pumping cold water in to replace it. It really doesn't take a genius to figure this out. Sadly, this is often not the case. Water is pumped out, nothing is replaced, and nature is expected to maintain the water levels.

Even worse, in some areas, the fresh hot water is replaced by cold salt water. This helps to maintain the balance of water level, but salt water has very different properties than does fresh water. It boils at a different temperature, and it leaves a corrosive salt residue, for instance. Salt water is also lighter than fresh water, so it is more likely to end up being sucked up by the pumping action.

Fresh water pumped out of a geothermal well is often discharged into a lake, stream, or river after it has cooled and the energy has been used. Salt water that is discharged can quickly taint the lake, stream, or river, and can contaminate the water table. This hurts every plant and animal that relies on the fresh water, though they may be miles away from the discharge point.

Klamath Falls, Oregon faced this problem early on. Geothermal energy is abundant in the area. Saltwater isn't an issue, since the town is over 200 miles from the ocean. There was still a problem. The water was used in water radiators for heat in the often-bitter winters, by both homes and businesses. There wasn't a problem when only a few buildings were heated in this way. Inflow of water easily replaced the amount pumped out.

However, as more homes and businesses began to use the geothermal heat, the water table began to drop. Thankfully, they figured out the solution easily. After the water has been used for heating, pump it right back into the ground. There is no need to discharge anything, and salt doesn't enter the picture. The pipes used still impart chemicals, but the same can be said of almost all energy sources, and the amount is small.

The biggest environmental concerns with using Geo energy is in regulating it so it doesn't harm the environment, and so it continues to provide the energy. This is one of the cleanest energy sources, but man needs to learn to work with the source rather than trying to exploit it. Done properly, there is no reason for concern. Done improperly, it can cause all kinds of havoc.

Sources:

Oregon DEQ
Klamath Falls Chamber of Commerce

Learn more about this author, Rex Trulove.
Click here to send this author comments or questions.