It’s Geothermal, But It’s….Where?
We haven’t heard too much about geothermal recently. When I was writing Renewable Energy–Facts and Fantasies almost 10 years ago, the interview I conducted with the leader in this space, Reno, NV-based Ormat Technologies left me with a sense of guarded optimism about the future of this technology, though a couple of years later, I met the company’s CEO at a conference, and she was far less sanguine. In the intervening period, most of the time we come across the word “geothermal” we see “Iceland” in the same sentence.
It’s for this reason that I was thrilled to see this project unfolding in Ethiopia. The entire world is hoping that the developing world can leapfrog right over dirty energy and more directly to renewables. Now there is renewed hope that this will, in fact, happen.
Craig,
You appear to have a somewhat simplified and overly optimistic understanding of the problems associated with Geo-Thermal energy extraction.
Geo-thermal energy, is derived from a number of separate sources depending on the location.
Each of the sources are very different and have differing pollution problems.
Some geo-thermal project produce large quantities of substances including carbon dioxide gases,hydrogen sulfide, methane, ammonia( etc.
These projects produce relatively low energy yields. Even very large plants create only a fraction of the energy of conventional fossil fuel plants yet can create the same problems in terms of emissions. Geo-thermal plants still need to be equipped with emission-control systems to reduce pollutants.
Toxic elements such as mercury, arsenic, boron, and antimony is also produced and needs to be re-injected back into the Earth to stimulate production.
Sound familiar ? Many Geo-thermal locations use “Clean Coal” technology to sequestrate pollutant emissions. (So much for “leapfroging right over dirty energy”).
In volcanic areas, land stability and subsidence can occur. Tectonic uplifts, subsidence and even sizable earthquakes are a risk.
Some site can be revived when depleted, while others remain uneconomic. It all depends on the source of the energy. Degraded Radio-active deposits also ‘wander’ about over time, making investment increasingly risky.
An interesting technology, but hugely capital intensive and often disappointing.