The Issues of Helium 3 as a Fusion Energy Source
If energy levels are reduced by a global reduction in the allowed use of fossil fuels post 2015 then what are the issues of using Helium 3 to provide an alternative sustainable fuel up to 2050?
This analysis gives an ongoing framework to test that question.
A Helium 3 Fusion Reaction
Helium 3 is not available on Earth in very large quantities. It has to be synthesized from mineral deposits.
To get the Helium 3 to a state where it can become a fuel it needs to be extracted, heated and combined with a secondary element, Deuterium.
The fusion reaction of Helium 3 with Deuterium can then be repeated in a fusion cascade manner to produce more energy.
For a fusion reaction to occur requires 1kg of Helium 3 with 0.67 kg of Deuterium,. This gives a reaction output of 18.4MeY (19MeY) after being heated to 900 deg C .
Source: Artemis Project: Lunar Helium-3 as an Energy Source
The JET fusion reactor in Oxford shire has already tested this process and achieved a fusion reaction.
The ITER fusion reactor is also being built currently to generate increased fusion energy.
The Production of Deuterium
Deuterium can be extracted from sea water on Earth.
Deuterium concentration in sea water
= 33 milligrams per litre of seawater
Source: http://www.iter.org/sci/fusionfuels
= 0.033 grams per 1,000,000 grams (1 Tonne)
= 1 gram of Deuterium per 30,303,030 grams
= 1 gram of Deuterium per 30.3 metric tonnes of Seawater
To obtain sufficient to start the fusion reaction
= 0.67 kg of Deuterium to 1 kg of Helium 3
= 670 grams x 30.3 tonnes
To obtain sufficient Deuterium requires
= 20,301 tonnes of seawater
The Deuterium Resource
Allowing for the water volume on Earth
= 1,335,000,000 km3
Source: NOAA's National Geophysical Data Center
= 352,670,000,000,000,000,000 gal
= 1,333,092,600,000,000,000,000 kg
= 1,333,092,600,000,000,000 m t of seawater
World reserve in years
= 1,333,092,600,000,000,000 / 20,301 tonnes
= 65,666,400,000,000,000,000 g of Deuterium
= 65,666,400,000,000,000 kg of Deuterium
= 65,666,400,000,000 t of Deuterium
This would indicate a large resource of Deuterium in seawater on Earth.
The Energy Yield Needed from Helium 3 and Deuterium Fusion to Replace Current Fossil Fuels
Allowing for 40 tons of Helium 3 to power the USA for 1 year and extrapolating
Source: Artemis Project: Lunar Helium-3 as an Energy Source
USA electricity consumption
= 3.886 trillion kWh (2010 est.)
Source: CIA World Factboook
40 tons of Helium 3 with Deuterium
= 3.886 trillion kWh (2010 est.)
40,000 kg of Helium 3 with Deuterium
= 3.886 trillion kWh (2010 est.)
1 kg of Helium 3 with Deuterium
= 97,150,000 kWh
Extrapolating to power the Earth for a year
= 19.54 trillion kWh (2009 est.)
Source: CIA World Factboook
1 kg of Helium 3 with Deuterium
= 97,150,000 kWh
201,132 kg of Helium 3 with Deuterium
= 19.54 trillion kWh
Approx. 200 tonnes of Helium 3 per year to power the earth for 1 year
Extrapolating for current World Fossil fuel Use
Fossil Fuel energy at 66.6% of total
= 12.89 trillion kWh
1 kg of Helium 3 with Deuterium
= 97,150,000 kWh
132,681 kg of Helium 3 with Deuterium
= 12.89 trillion kWh
Approx. 150 tonnes of Helium 3 per year to power the Earth for 1 year
to replace all fossil fuel energy consumption
Combining this resource with the required amount of Helium 3 to produce energy 1kg of helium 3 with 0.67 kg of Deuterium, after allowing for heating energy to 900 deg C. = 18.4MeY (Megawatt Years)
= 161,290,955 kilowatt hours
Source: Artemis Project: Lunar Helium-3 as an Energy Source
1 million metric tonnes of Helium 3, with deuterium, can produce
= 20,000 terawatt-years
1,000,000,000 kg of Helium 3 with Deuterium
= 20,000 terawatt years
= 175,316,255 terawatt hours
= 175,316,255,000,000,000 kWh
= 20,000,000,000,000 kW years
1 kg of Helium 3 with Deuterium
= 20,000 kW years
= 175,316,255 kilowatt hours
There is a range of variances in output from the reaction between Helium 3 and Deuterium depending on what it is used for. 97,150,000 kWh, 161,290,955 kilowatt hours and 175,316,255 kilowatt hours.
In terms of resources the current fusion equation very crudely requires a ratio of Deuterium to Helium 3 of 1 to 1.5
A second comparison using this 1 to 1.5 ratio between the Deuterium and the Helium 3 resources needed produces.
= 65,666,400,000,000 t of Deuterium available at a ratio of Deuterium to Helium 3 of 1 to 1.5
= 98,499,600,000,000 tonnes of Helium 3 needed
Approximately 100 trillion tonnes of Helium 3 are needed to match the Earth Deuterium reserve energy potential.
Unlike the Deuterium resource detailed earlier Helium 3, however, does not have the same level of abundance on Earth.
Helium 3 reserves accessible on Earth
The simplest source of Helium 3 would be through the reclamation of nuclear weapons.
Amount available from nuclear weapons reclamation
= 15kg of Helium 3 /yr
Source: Artemis Project: Lunar Helium-3 as an Energy Source
Amount currently in reserve / year
= 8kg of Helium 3 / yr
Source: The Helium 3 Shortage: Supply, Demand, and Options for Congress
USA Strategic reserve
= 29kg of Helium 3
Source: Artemis Project: Lunar Helium-3 as an Energy Source
Natural gas reserves
= 187kg of Helium 3
Source: Artemis Project: Lunar Helium-3 as an Energy Source
Reserve total
= 239 kg of Helium 3
This would potentially power the USA for 6 months.
This is far below the amount of Helium 3 resources to balance the potential Deuterium resources on Earth and obtain the maximum power output potential to meet energy demands.
Other Helium 3 resources are to be found on the Moon.
Helium 3 reserves accessible on the Moon
The estimated amounts of Helium 3 in the Moon regolith vary in publications.
Amount of Helium 3 in total lunar regolith
= 2,469,000 tons
Source: THE ESTIMATION OF HELIUM-3 PROBABLE RESERVES IN LUNAR REGOLITH. E. N. Slyuta1 and A. M. Abdrakhimov1, and E. M. Galimov1 1V.I. Vernadsky Institute of Geochemistry and Analytical Chemistry (Russia, Moscow, 119991, Kosygina, 19, albertabd@mail.ru)
Amount of Helium 3 in lunar regolith
= 1,100,000 tons
Source: Mining the Moon for Helium3 - BBC Documentary
Abundance of Helium 3 in lunar regolith
= 1 gram per 150 tonnes of lunar regolith
= 1 tonne per 150,000,000 tonnes of lunar regolith
Source: The Challenge of Mining He3 on the lunar surface How all the parts fit together. Wisconsin Centre for Space Automation and Robotics. I.N. Sviatoslavsky 1993
Depth of lunar regolith
= 4 to 15 m thick
= average approx. 10m thick
Moon Surface Area
= 37,930,000 km2
= 37,930,000,000,000 m2
Moon approx. Total volume of regolith
= 379,300,000,000,000 m3
= 379,300,000,000,000,000,000 cm3
Allowing a density of 1.5g/cm3
= 5,689,500,000,000,000,000,000 g
Amount of lunar regolith
= 5,689,500,000,000,000 tonnes
Amount of Helium 3 available over total surface
= 5,689,500,000,000,000 / 150,000,000
= 37,930,000 tonnes of Helium 3
Amount of moon surface needed to be mined is 100 % of the moon surface if exploratory dredger mining employed. (Given the various geographic nature of the moon 100th of the moon surface seems a valid conclusion.
= 37,930,000 km2
37,930,000 tonnes of Helium 3 would power the Earth for 189,650 years.
This is still far below the amount of Helium 3 resources to balance the potential Deuterium resources on Earth and obtain the maximum power output potential to meet energy demands.
This is, however, still an excessive proposal for mining the Moon.
More realistic Moon mining options can be tested against each of the estimated amounts of Helium 3 on the Moon and some assumptions.
Appraisal of Mining the Moon for Helium 3
Testing each of the estimated amounts of Helium 3 in the Moon regolith from publications to establish estimates for mining area, resource amounts, resource lifespan, resource value, total miners, total spacecraft, habitation area, costs for transport of miners and machinery and total costs and allowing for the following assumptions an appraisal of the best moon mining option can be made.
Assumptions
To send 3 people to the moon cost at maximum $8,720,000,000 in 2014 money.
Approx... $3,000,000,000 per astronaut
Source: Apollo Program Budget Appropriations NASA.
Allowing the weight of one astronaut to be 137 pounds or 63 kg then the payload for each human transport would be 189 kg approx. 200 kg.
Allowing for the transport of machinery the energy required for each rocket would need to be 5 times that of a Saturn 5 type lift vehicle to carry one tonne of machinery. In the following cost analysis a factor of 10 has been employed.
Allowing for 10m mining depth on average
Allowing for 50m mining depth as a possible using current surface mining technology.
Allowing for draglines, power shovels, large transport vehicles, excavators, conveyors, drillers, and possibly explosive fracturing methods. The mining also needs.Equipment to carry out prospecting, Energy to run the mining facility and habitation, Maintenance of mine and habitation areas, Supply and construction and spaceship landing areas, Conversion of lunar regolith into Helium 3 facility, Transport of Helium 3 to Earth, Production of Deuterium from Seawater to use with Helium 3 in creating energy, Human settlement needs, Resources for miners
Allowing for 100 people per mine and; to make an area comparison using Britain in which there were once 1000 coal mines; allowing for 1000 mining areas.
Allowing for a payback of $2,000 per liter, $15,000 per gram of Helium 3
Source: USA DOE
Total Moon surface mined
= 37,930,000 km2 (155 times the area of Britain)
Helium 3 resource
= 37,930,000 tonnes
= 37,930,000,000,000 grams x $15,000
= $568,950,000,000,000,000 total value
Total available time of resource at 200 tons/yr
= 189,650 years
Total number of miners
= 155 x 1000 x 100
= 15,500,000 miners
= 5,166,666 spacecraft
= A habitation area the size of London Metro area
Total transport cost for miners
= $46,500,000,000,000,000
Total transport cost for all other items say x 10
= $465,000,000,000,000,000
37,930,000 tonnes of Helium 3 would power the Earth for 189,650 years.
Or
7 % of Total moon surface mined = 2,655,100 km2 (11 times the area of Britain)
Helium 3 resource =2,469,000 tonnes
= 2,469,000,000,000 grams x $15,000
= $37,035,000,000,000,000 total value
Total available time of resource at 200 tons/yr
= 12,345 years
Total number of miners
= 11 x 1000 x 100
= 1,100,000 miners
= 3,300,000 spacecraft
= A habitation area 7% the size of London Metro area
Total transport cost for miners
= $3,300,000,000,000,000
Total transport cost for all other items say x 10
= $33,000,000,000,000,000
2,469,000 tonnes of Helium 3 would power the Earth for 12,345 years.
Or
3% of total moon surface mined
= 1,137,900 km2 (5 times the area of Britain)
Helium 3 resource
= 1,100,000 tonnes
= 1,100,000,000,000 grams x $15,000
= $16,500,000,000,000,000
Total available time of resource
= 5,500 years
Total number of miners
= 5 x 1000 x 100
= 500,000 miners
= 1,500,000 spacecraft
= A habitation area 3% the size of London Metro area
Total transport cost for miners
= $1,500,000,000,000,000
Total transport cost for all other items say x 10
= $15,000,000,000,000,000
1,100,000 tonnes of Helium 3 would power the Earth for 5,500 years.
The Volume of Helium 3 Issue.
Size of transport Containers for Helium 3 gas
Allowing for Helium 3 Density at 21.1°C (70°F)
= 0.1650 kg/m3
Source: http://www.helium-3.com/description.html
Allowing 1000 kg per metric tonne
= approx.6060 kg/ tonne
This requires a container of volume
= approx. 6060 m3 / tonne
Compared to a Saturn 5 rocket
= 110.6m x 10.1m
= 1117 m3
This requires a storage volume approx. 6 times that of the Saturn 5 lift vehicle.
This entails another stage in the Helium 3 production. Some form of pressurization for transport.
This allows much smaller Helium 3 consignments and smaller lift vehicles, potentially those already in use in space exploration such as the Russian and ESA satellite lift vehicles.
Light Changes
Mining the Moon could reduce the light reflected from the Sun onto the Moon onto Earth at night and so make the nights darker.
This would change human energy consumption needs.
This would also change environmental conditions.
Moon Mass Changes
The mining of the lunar surface will change its overall mass.
This could have additional effects on the orbit, tilt and stability of the Moon.
It could also alter the tidal effects on the Earth.
Conclusions
Energy resources are depleting due to global demand.
Energy resources producing greenhouse gases must be reduced to reduce global warming.
66.6% of the Earths energy generation is from fossil fuels. (Source: CIA World Factbook 2013)
Alternative, non-fossil, non-greenhouse gas producing, non-carbon energy fuels must be sought out to replace at least the 66.6 % of the Worlds Energy but also to exceed this amount if humans are to progress technologically.
Hydrogen as a fusion energy resource is beyond our current containment technology.
Lithium as a fusion energy resource is within our current containment technology and can be extracted from seawater.
Helium 3 as a fusion energy resource is within our current containment technology but must be extracted from lunar regolith to be a viable fusion fuel source.
Tritium as a fusion energy resource is within our current containment technology and can be extracted from Lithium and reacted with Deuterium resources.
Deuterium as a fusion energy resource is within our current containment technology and can be extracted from seawater and used with Lithium, Tritium or Helium 3 in Fusion reactions.
Therefore the initial phase of the fusion process should be to establish the method of Deuterium extraction and reaction since this allows more fusion technology options.
Mining the whole Moon surface only achieves a minor amount of Helium 3 resources to balance the potential Deuterium resources on Earth and obtain the maximum power output potential to meet energy demands.
This is however still an excessive proposal.
A small operation by mining less than 3% of the moon surface can obtain a suitable Helium 3 resource of 1,100,000 tonnes.
This when checked against the very crude ratio needed of Deuterium to Helium 3 of 1 to 1.5 puts an estimate for the Deuterium required at 733,333, approximately 750,000 tonnes. Less than the potential Deuterium resources in Earth oceans. This is therefore environmentally sustainable.
The Small 3% mining operation has the following characteristics.
A mining area of 1,137,900 km2 This is still approximately 5 times the area of Britain.
A total of 500,000 miners
A total number of 1,500,000 spacecraft as transports
A habitation area of 3% the size of the London Metropolitan area
A total transport cost for miners of approx. $1,500,000,000,000,000
A total transport cost for all other items say x 10 the human weight cost $15,000,000,000,000,000
A total cost of $16,500,000,000,000,000. 17 Quadrillion dollars.
This is approx. 237 times the current total world product.
This compared to the return sale value of the Helium 3 as a fuel of approx. $16,500,000,000,000,000.
17 Quadrillion dollars. This means that it as an exercise could only break even on costs.
Allowing for a 2013 / 2014 rate of energy use this gives a Helium 3 resource use of 200 tons of Helium 3 per year.
This gives a total life of the Helium 3 Moon resource of 5,500 years of potential energy.
Other issues are potentially more extreme variations to the environment of Earth.
This fuel source requires retention of some of the nuclear plants to isolate the Deuterium from seawater.
This option requires maintaining fossil fuel supplies and so altering the Earth’s climate.
The volume of container needed to transport the Helium 3 is enormous at current storage technologies but to get less than 1 tonne of the gas from the Moon to the Earth would not be as cost effective. Therefore new lift vehicle and pressurized storage technologies are required.
The alteration to the reflectance of the Moon onto the Earth by the mining needs to be considered.
The alteration potentially to the mass, tilt or orbit of the Moon by the mining needs to be considered.
The costs to use Helium 3 as a potential energy source for the future are so high as to threaten the economic, political and social stability of Earth.
If humans do not progress this option then there future is certain. They will run out of fuel and resources and regress technologically.
Therefore the Moon mining of Helium 3 and the ocean extraction of Deuterium must be progressed.
Ian K Whittaker
Websites:
https://sites.google.com/site/architecturearticles
Email: iankwhittaker@gmail.com
08/08/2014
14/10/2020
2763 words over 7 pages.