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Nuclear fusion: Difference between revisions
→Scarcity of fuels
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==Scarcity of fuels== | ==Scarcity of fuels== | ||
{{sum|Problem in some cases}} | {{sum|Problem in some cases}} | ||
{{dp | |||
|hydrogen_fusion.energy_by_mass | |||
|626984714 MJ/kg | |||
|Energy that can be obtained by nuclear fusion of hydrogen atoms | |||
}} | |||
{{dp | |||
|water.hydrogen_by_mass | |||
|(hydrogen*2)/(hydrogen*2+oxygen) | |||
|How much of water's mass is hydrogen | |||
|About 11%. Calculated using chemistry constants built into the calculator. | |||
}} | |||
{{dp | |||
|oceans.volume | |||
|1.35 billion km^3 | |||
|Total volume of all oceans on Earth | |||
|https://hypertextbook.com/facts/2001/SyedQadri.shtml | |||
}} | |||
{{dp | |||
|fossil_fuels.consumption | |||
|11596.92 Mtoe/year | |||
|Total consumption of coal, oil, and natural gas (worldwide) (energy units) | |||
|<nowiki>Key World Energy Statistics 2020 (IEA report)</nowiki><br /><nowiki> | |||
- page 47: World energy balance, 2018</nowiki><br /><nowiki> | |||
- - Total Energy Supply (TES), first 4 columns combined</nowiki> | |||
}} | |||
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There are no viable reactors yet, but of the prototypes so far, some rely on tritium, an extremely rare form of hydrogen. Supply would be an issue. | There are no viable reactors yet, but of the prototypes so far, some rely on tritium, an extremely rare form of hydrogen. Supply would be an issue. | ||
Other possible fuels include deuterium, lithium or boron, which are comparatively less rare. In any case, only small amounts of the fuel would be needed to produce large amounts of energy.{{qn}} | Other possible fuels include deuterium, lithium or boron, which are comparatively less rare. In any case, only small amounts of the fuel would be needed to produce large amounts of energy.{{qn}} | ||
Ideally, fusion reactors could rely on ordinary hydrogen, which would be abundant enough to last | Ideally, fusion reactors could rely on ordinary hydrogen, which would be abundant enough to last for billions of years. | ||
{{p2|[show maths]| | |||
If we assume...{{pbr}} | |||
~ that losing '''0.1%''' of the world's oceans would be enough to be a problem, and{{pbr}} | |||
~ that hydrogen fusion energy consumption would '''equal''' today's fossil fuel energy consumption (no growth),{{pbr}} | |||
Then it would take more than a hundred billion years to have even a minor effect on the ecosystems: | |||
{{calc | |||
|0.1% oceans.volume waterdensity water.hydrogen_by_mass | |||
|billion years (fossil_fuels.consumption / hydrogen_fusion.energy_by_mass) | |||
|||Side note: For the same amount of energy, the hydrogen losses are even less than the would-be atmospheric losses in a non-nuclear scenario where [[hydrogen gas]] replaces [[natural gas]]. | |||
}} | |||
}} | |||
For now, all of this is hypothetical - regardless of fuel, no prototype so far has been able to produce more energy than it takes to run it. | For now, all of this is hypothetical - regardless of fuel, no prototype so far has been able to produce more energy than it takes to run it. | ||