The Inefficient Sun
There is a current myth about Fusion energy that it is the solution to Earth Energy needs.
This essay examines this myth through the energy efficiency of the only long term use operating fusion reactor we know, the Sun. It examines energy input, energy output, energy distribution to Earth, energy distribution to Earth surface and technological collection of energy by humans. It then compares the current state of fusion research on Earth and its expected future to meet our needs.
The Sun Energy Input to Output
The Sun converts Hydrogen into Helium in a fusion reaction.
74.9% of the mass of the Sun is Hydrogen, 23.8 % of the Sun is Helium.
This gives a Hydrogen to Helium ratio of 3 to 1
The Sun converts 3 times more mass than the energy it produces.
Inefficiency 001 = 3:1
The Sun Energy distribution to Earth
The amount of energy emitted in one second by the Sun is twice the amount hitting the Earth.
Inefficiency 002 = 2:1
The Sun energy distribution to the Earth surface
Of the 174 petawatts reaching the Earth 51% is reflected, radiated or absorbed.
This leaves a total of 89 petawatts of energy that can be collected by humans over the whole surface of the Earth.
Inefficiency 003 = 2:1
The collection of the Sun energy by humans.
Of the approximately 1000 w/m2 of Sun Energy hitting the earth surface only 100 watts can be collected by human technology.
Of this 100 watts only 10% can be collected and transformed into electricity.
Inefficiency 004 = 20:1
Total Ratio of Energy Input to Energy Output
27 : 1
Therefore the Sun is inefficient and the inefficiencies multiply through to a human collection level.
If the Sun is considered as a Fusion reactor then it may also be considered inefficient.
The Fusion Energy Status on Earth
The energy input into a fusion reaction in the Jet reactor in the UK in 1997 was 24Mw to get 16 Mw out.
Source: http://en.wikipedia.org/wiki/Joint_European_Torus
This is a major human achievement since it doubled the efficiency of that used in the Sun.
Inefficiency 005 = 1.5:1
The fusion process requires, at present, approx. 600g of Tritium and 400g of Deuterium.
This amount of fuel generates approx. 1,500 Mw. 1,500,000 kW
Source: https://www.euro-fusion.org/faq/you-state-that-a-fusion-reactor-would-generate-1500-megawatts-but-what-is-the-time-span-in-which-that-amount-is-produced/
The cost of the fuel supply of Tritium and Deuterium is approx. $30,000 US dollars per gram.
Source: Willms, Scott (14 January 2003). "Tritium Supply Considerations". Los Alamos National Laboratory. Retrieved 1 August 2010.
This gives a fuel cost of $ 30,000,000
At the cost of domestic electricity in the USA at 12cents a Kwh this equates to a value of approx. $180,000.
Source: http://shrinkthatfootprint.com/average-electricity-prices-kwh
$20,000,000 input = $180,000 output.
Inefficiency 006 = 166:1
Total Ratio of Energy Input to Energy Output
167.5:1
The Future predicted Fusion Energy Status on Earth
The ITER fusion reactor is due to be completed in 2019.
Its energy generation potential is aimed to be 50Mw input to get 500 Mw output.
Efficiency 1 : 10
This has yet to be proven.
Conclusion
The natural forms of fusion energy are inefficient.
The human technological forms of fusion energy are potentially; as proven by the JET reactor; more efficient than the Sun.
The cost of fuel and the value of the energy input on a large scale have yet to be made as efficient as the natural forms of fusion energy.
The current myth about Fusion energy that it is the solution to Earth Energy needs is therefore proven.
However if ITER can be made to work and produce its own energy then the technological leap from a Carbon, Uranium economy to Lithium, Tritium, Deuterium economy will allow humans to move up by a factor of five in energy level potential.
Therefore Fusion energy is still a natural myth that is worth researching.
It will turn humans into self- believing technologists that can make things more efficient than the Sun.
Ian K Whittaker
Websites:
https://sites.google.com/site/architecturearticles
Email: iankwhittaker@gmail.com
28/03/2015
14/10/2020
680 words over 2 pages