242
ground upgradient of the production well, where it flows through the aquifer and
transfers heat to the rocks. Depending on the size of the solar component, these
systems can reportedly get quite hot.
Once the rocks warm up, an aquifer that was previously too cold for effective
geothermal use can supply abundant hot water at efficient temperatures. The hybrid
system avoids the intermittent power losses of other solar systems like photovoltaics
due to night or cloudy days. More solar heat can be injected downhole during sunny
periods or seasonally to build up the temperature, and the thermal inertia of the rock
allows the aquifer to continuously produce hot water, day or night, rain or shine.
Advantages of the solar-geothermal hybrid include shallower wells than those
required for EGS, saving on drilling costs. It can also be developed in an aquifer
rock that has high porosity and permeability, thereby avoiding the need for hydraulic fracturing that will create preferential flowpaths between wells. Flow through a
uniform porous medium like clean, well-sorted sandstone would be much more
effective for heat exchange with the surrounding rock than flow through fractures.
There are many engineering challenges to overcome, but if solar heat can be used to
create geothermal groundwater in locations that previously had no geothermal
resources, this could be a revolutionary source of energy.
The energy future will be a place where petroleum engineers focus on the capture
and underground storage of carbon dioxide, drillers learn how to emplace geothermal wells into hot, deep rock, and geologists monitor the stability of high level
nuclear waste. The only thing constant is change, and those who can adapt will do
well. Those who cannot will be left behind.
12.2 Preserving Earth
It has been said that the Earth is the cradle of humanity, but one cannot remain in the
cradle forever. There is no doubt that humans have been detrimental to the environment, and if we don’t change our evil ways, there will be a big bill coming due soon.
Humanity has become like an unemployed, middle-aged child living in our mother’s basement surrounded by empty pizza boxes, crushed soda cans, and video
games. We have without question trashed the place, and strained our poor old mother’s ability to support us.
Some philosophers have recommended that humans should just stop breeding
and quietly become extinct as a way to create a future world without human impacts
where other creatures can thrive (MacCormack 2020). While this would indeed ease
our impact on nature and eventually allow the Earth to heal, we won’t be around to
see it. Given the human obsession with sex, this probably won’t happen, nor should
it. The idea of restoration through extinction is nothing less than a cop-out that
places an unfair burden on future generations by telling them we screwed up the
planet so badly that you can’t even be born. Rather than giving up and fading away,
we owe it to our great-great grandchildren to fix the mess. There is no other
moral answer.
12 Moving into the Energy Future
ground upgradient of the production well, where it flows through the aquifer and
transfers heat to the rocks. Depending on the size of the solar component, these
systems can reportedly get quite hot.
Once the rocks warm up, an aquifer that was previously too cold for effective
geothermal use can supply abundant hot water at efficient temperatures. The hybrid
system avoids the intermittent power losses of other solar systems like photovoltaics
due to night or cloudy days. More solar heat can be injected downhole during sunny
periods or seasonally to build up the temperature, and the thermal inertia of the rock
allows the aquifer to continuously produce hot water, day or night, rain or shine.
Advantages of the solar-geothermal hybrid include shallower wells than those
required for EGS, saving on drilling costs. It can also be developed in an aquifer
rock that has high porosity and permeability, thereby avoiding the need for hydraulic fracturing that will create preferential flowpaths between wells. Flow through a
uniform porous medium like clean, well-sorted sandstone would be much more
effective for heat exchange with the surrounding rock than flow through fractures.
There are many engineering challenges to overcome, but if solar heat can be used to
create geothermal groundwater in locations that previously had no geothermal
resources, this could be a revolutionary source of energy.
The energy future will be a place where petroleum engineers focus on the capture
and underground storage of carbon dioxide, drillers learn how to emplace geothermal wells into hot, deep rock, and geologists monitor the stability of high level
nuclear waste. The only thing constant is change, and those who can adapt will do
well. Those who cannot will be left behind.
12.2 Preserving Earth
It has been said that the Earth is the cradle of humanity, but one cannot remain in the
cradle forever. There is no doubt that humans have been detrimental to the environment, and if we don’t change our evil ways, there will be a big bill coming due soon.
Humanity has become like an unemployed, middle-aged child living in our mother’s basement surrounded by empty pizza boxes, crushed soda cans, and video
games. We have without question trashed the place, and strained our poor old mother’s ability to support us.
Some philosophers have recommended that humans should just stop breeding
and quietly become extinct as a way to create a future world without human impacts
where other creatures can thrive (MacCormack 2020). While this would indeed ease
our impact on nature and eventually allow the Earth to heal, we won’t be around to
see it. Given the human obsession with sex, this probably won’t happen, nor should
it. The idea of restoration through extinction is nothing less than a cop-out that
places an unfair burden on future generations by telling them we screwed up the
planet so badly that you can’t even be born. Rather than giving up and fading away,
we owe it to our great-great grandchildren to fix the mess. There is no other
moral answer.
12 Moving into the Energy Future