Are Volcanoes Good Sources of Energy?

When I read that sentence, I envision someone trying to poke something into the middle of a stratovolcano's caldera and the volcano erupting on them right then. Maybe I've watched too many end-of-the-world disaster films, but that image persists in my head. Never mind. Energy companies aren't likely to plants on top of active stratovolcanoes that might erupt any time soon. That's just my silly visualization. So, how do we get energy from volcanoes? First, let's see where the energy is.

Where does the energy come from?

Through indirect evidence scientists have composed a model for the earth's structure. At the very center of the earth is a high pressure, high temperature, zero gravity, solid core. Surrounding this inner core is an outer core about the size of the moon that is liquid. Beyond the liquid, outer core is the earth's mantle, which is a solid molten rock which can flow, slowly. On top of the mantle is the earth's crust. We live on the earth's crust. It's about 30 miles deep and floats on top of the earth's mantle. The crust is broken into different plates

The plates are called tectonic plates. They can move toward each other (converging), in which case one plate will go underneath the other in a process called subduction. The plates can more away from each other (divergent), and the mantle flows upward and creates new crust in the areas between separating plates. The plates can also move by each other (transform).

The most obvious times that earth releases its energy is when earthquakes occur or volcanoes erupt, but earth constantly releases energy.

The energy in the earth is geothermal energy.

The magma from the earth's mantle breaks through parts of the earth's crust, and that's pretty much a volcano. The magma also seeps into the earth's crust at points. Geysers are powered by water seeping into the ground, coming into contact with hot rocks, heating up, and exploding upward. Geysers typically occur in volcanic areas. Hot springs occur in non-volcanic areas, but by a similar process. Water seeps down, gets hot, and comes back up, but not as violently.

Most geothermal energy is harvested at tectonic plate boundaries, but scientists have discovered how to access the earth's energy in other areas.

Is this energy good energy?

As with most things in life, there are pros and cons. Geothermal energy is natural. We're not burning carbon. We're not making radioactive waste. We're just using what's already there. This is good.

There is potential with geothermal energy, however, to tap release gas. The gases releases can be simple oxygen and carbon dioxide. Carbon dioxide is a greenhouse gas, so that can be concerning. There's also some poisonous gases that can be released.

Overall, the volume of greenhouse gases released from harvesting geothermal energy is small compared to what we release by driving cars, and is less gas emitted from carbon burning plants creating the same amount of energy.

So, in a way, volcanoes are a good source of energy.

Gwen Nicodemus is a freelance engineer/writer and a homeschooling mom. Visit her website, Notion Nexus, for unit studies, worksheets, notes, and educational videos.