# geothermic energy

**URL:** <https://boards.straightdope.com/t/geothermic-energy/608220>\
**Category:** Factual Questions\
**Created:** [January 3, 2012, 2:41am UTC](https://boards.straightdope.com/t/geothermic-energy/608220 "2012-01-03T02:41:42Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![ballardfam](https://avatars.discourse-cdn.com/v4/letter/b/8797f3/32.png) [@ballardfam](https://boards.straightdope.com/u/ballardfam)\
**Post date:** [January 3, 2012, 2:41am UTC](https://boards.straightdope.com/t/geothermic-energy/608220/1 "2012-01-03T02:41:42Z")

</div>

How long to exhaust even geothermic resources?

---

<div class="post-metadata">

**Author:** ![Duckster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/duckster/32/1244_2.png) [@Duckster](https://boards.straightdope.com/u/Duckster)\
**Post date:** [January 3, 2012, 2:54am UTC](https://boards.straightdope.com/t/geothermic-energy/608220/2 "2012-01-03T02:54:34Z")

</div>

> [@](#):
>
> Geothermal power is considered to be [sustainable](https://en.wikipedia.org/wiki/Sustainability) because any projected heat extraction is small compared to the Earth’s heat content. The Earth has an internal heat content of [1031 joules](https://en.wikipedia.org/wiki/1_E31_J) (3·1015 TW·hr).[[3]](https://en.wikipedia.org/wiki/Geothermal_energy#cite_note-IPCC-2) About 20% of this is residual heat from [planetary accretion](https://en.wikipedia.org/wiki/Gravitational_binding_energy), and the remainder is attributed to higher radioactive decay rates that existed in the past.[[1]](https://en.wikipedia.org/wiki/Geothermal_energy#cite_note-turcotte-0) Natural heat flows are not in equilibrium, and the planet is slowly cooling down on geologic timescales. Human extraction taps a minute fraction of the natural outflow, often without accelerating it.

[Geothermal energy - Wikipedia](https://en.wikipedia.org/wiki/Geothermal_energy#Sustainability)

---

<div class="post-metadata">

**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\
**Post date:** [January 3, 2012, 7:30am UTC](https://boards.straightdope.com/t/geothermic-energy/608220/3 "2012-01-03T07:30:49Z")

</div>

10^31 Joules, I suspect that should be…

---

<div class="post-metadata">

**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\
**Post date:** [January 3, 2012, 12:47pm UTC](https://boards.straightdope.com/t/geothermic-energy/608220/4 "2012-01-03T12:47:58Z")

</div>

> [@Mangetout](#):
>
> 10^31 Joules, I suspect that should be…

The hamsters quite understandably eat the carets when importing such data. 🙂

---

<div class="post-metadata">

**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\
**Post date:** [January 3, 2012, 2:10pm UTC](https://boards.straightdope.com/t/geothermic-energy/608220/5 "2012-01-03T14:10:50Z")

</div>

> [@Mangetout](#):
>
> 10^31 Joules, I suspect that should be…

Rats - I was hoping we could finally cool this thing off and drill down to the center, the way Hollywood has been promising.

To answer the OP: probably well into the billions of years.

---

<div class="post-metadata">

**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\
**Post date:** [January 3, 2012, 2:44pm UTC](https://boards.straightdope.com/t/geothermic-energy/608220/6 "2012-01-03T14:44:45Z")

</div>

> [@Mangetout](#):
>
> 10^31 Joules, I suspect that should be…

…enough power to finish typing this sentence?