Climate, Energy Roundup (Geothermal Fracking, Oil Spills, NBA Green Week…)

It is important to note, that this is not true for every well for
either FF or geothermal. These are simply trends and both should have environmental standards in place that they are required to meet as both can have substantial environmental and safety impacts if used indiscriminately. It is my belief, based on the data I have seen that both forms of fracking can be safe and the issue is not in the technology itself, but rather how certain companies apply this technology and the handle wastes that they produce. That being said, it is my belief that Geothermal does have an inherent advantage. Here is my reasoning:

To start off with, the problem with fracking pollution isn’t the fracking fluid itself, but rather the substances that you release from the rock. (although that doesn’t hold true for all companies, as a technology, the fluid isn’t the problem.)

With FF fracking, you are looking for pockets rich in “deposits.” While the deposits that you want are hydrocarbons, they also tend to have other substances in close proximity, and when these other substances are found, there’s less incentive to avoid them as they can “simply” be pumped back in to replace the oil being extracted.

For Geothermal, you are looking for rock formations with adequate thermal energy that will allow for substantial flow. They use fracking to increase flow rates through rocks that have adequate thermals but are lacking in flow. Since these rock formations already tend to allow some flow, they also tend to lack trapped deposits. (This is not always true, but simply a trend. Just like some companies use fracking fluid that is dangerous, some companies will frack Geothermal areas with toxic deposits if allowed to, but this is not a fundamental of the technology.)

Because of this the fluid in Geothermal tends to be significantly less hazardous than in FF extraction.

Also, FF fracking drills, fracks, extracts and re-pressurizes the undesired fluid back into the wells. If done correctly and responsibly the only significant risk of a leak occurs during the re-pressurizing stage. (although, to my knowledge, the majority of the issues in FF extraction occur at the extraction phase because of improperly cured concrete – but that’s a rant for another time.)

In Geothermal, there is no re-pressurizing stage. They drill, frack and circulate. Sure the circulating with pressurize brine back into the well, but these pressures are rarely (if every) in the same range as with FF re-pressurizing.

Because of this, the brine is much less likely to contaminate any reservoirs.

Also, since it is the same water being circulated time and again, you can actually establish a cleaning station that extracts some of the dissolved chemicals – which depending on the mixture may actually have market value. (although unlikely to be economically viable using current technology, the price of the chemicals – usually metals – can be used to offset the costs of separating them from the water.) Many think this same technology could be applied to the FF brine, but they miss a key detail – with the geothermal brine, if you clean 1% out every cycle, only 37% remains after 100 cycles and this can be done constantly until the brine hits any arbitrary limit set for safety standards. For the FF brine – you only use it once, or a very limited number of times, so while you can filter it multiple times, this doesn’t give any advantage. You have to do a large scale filtration instead of small constant filtration.

Sorry if I’m not explaining this point well, but basically it’s the same reason why only part of our blood goes through our kidneys each cycle instead of pumping it all through every time. It’s more efficient to do it in small increments that constantly improve quality than to have to fix the problem all at once.

Because of this, the brine can be filtered to meet just about any arbitrary limit.

So in summary, Geothermal has the advantage that it’s brine is inherently less hazardous, it is handled at lower pressures and inherently less likely to contaminate other underground reservoirs and it can be filtered to meet specified limits with minimal impact on the economics of the operation.