Fusion?

[pocaracas]

According to an estimate I once saw, fusion using Deuterium and Tritium (the two "best" hydrogen isotopes for the task) can supply mankind with electricity for about 2000 years, considering we extract all the deuterium from sea water and the tritium from lithium.
After that, the world's oceans will be depleted of deuterium and the next closest source of it is.... the sun (or maybe Europa).

Actually Earth's fusion resources are more than a million times greater than all other energy reserves put together. Even at ten times our current rate of consumption, there is enough fusion fuel on this planet (alone) to power our civilization for nearly a billion years.

Well, I was working from memory... let's try to do the math, then!

http://www.world-nuclear.org/info/Curren...ion-Power/
"A 1 GW (electric) fusion plant will need about 100 kg deuterium and 3 tons of natural lithium to operate for a whole year, generating about 7 billion kWh. "

"30 grams per cubic metre"

http://oceanservice.noaa.gov/facts/oceanwater.html
"According to the U.S. Geological Survey, there are over 332,519,000 cubic miles of water on the planet. (=1.38599965 × 10^18 cubic meters)"

http://www.eia.gov/cfapps/ipdbproject/ie...&unit=BKWH
20000 billion kWh per year - electricity generation in the world


- How much deuterium do we need per year, today?
20000 / 7 * 100 = 285714 kg
-How much seawater must be filtered per year?
285714 / 0.03 = 9.5 × 10^6 cubic metres

- How many years of water are there?
1.38599965 × 10^18 / 9.5 × 10^6 = 145 529 963 250 years


So, that makes the nice number of 145 billion years.... ok, I guess there's enough to outlast the sun's demise!

Maybe the estimation I heard was concerning lithium....

I've also heard that ITER alone will use up about half the world's helium stock so cool the massive super-conductive coils... but fusion generates helium, so maybe we can restock on that....

Even if you don't want nuclear fusion we should push our governments to substitute oil and coal with something clean for which there already are solutions by scientists with existing technology, because if we don't do anything we may likely be the last generation of humans living on this planet.

But I do want... that's part of the reason I'm working in the field!