I did some numbers a while ago you may be interested in:
If all power generated right now was from D+T fusion, it would generate about 8.2% of the current helium consumption.
We consume 153,596 TWh of thermal energy per year [1].
Each D+T reaction releases 17.59 MeV [2].
Multiply by the atomic mass of He4 and divide by Avogadro's number to get the mass of He4 produced per energy produced.
Divide by the density of He4 at STP to get volume of He4 produced per second [3].
Divide by the consumption of He4 to get the ratio of He4 produced to He4 consumed [4].
If all power generated right now was from D+T fusion, it would generate about 8.2% of the current helium consumption. We consume 153,596 TWh of thermal energy per year [1]. Each D+T reaction releases 17.59 MeV [2]. Multiply by the atomic mass of He4 and divide by Avogadro's number to get the mass of He4 produced per energy produced. Divide by the density of He4 at STP to get volume of He4 produced per second [3]. Divide by the consumption of He4 to get the ratio of He4 produced to He4 consumed [4].
https://www.wolframalpha.com/input/?i=(153596+TWh+%2F+year)+...
1. https://ourworldindata.org/energy-production-and-changing-en...
2. http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/fusion.htm...
3. https://www.engineeringtoolbox.com/gas-density-d_158.html
4. https://link.springer.com/article/10.1007/s11053-017-9359-y