Is Boron a good enough energy source?

[MTd2]

10 thousand tones of Boron = 10^10g

10^10g has 6×10^23×10^10×10^-1 = 6×10^32 atoms of boron, since 1 mol of boron has aprox. 10g

An atom of boron yields 8MeV, so, the total output is 4.8×10^40eV. In joules, it would give 8*10^21J

The net output of that is around 10%, for commercial use, so, it means 10^21J, aprox.

The total consumption of energy of the world is 35TW or 3.5*10^13W which means 10^22J every year. To match this production, around 100thousand tones every of boron should be used.

The known commercial reserves of borate BO3(-3) are 10 milllion tons, which gives at best 1 – 2millions tons of pure boron.

So, we would have, at the very best, 20 years to finish all boron.

I hope I am wrong…

[Aeronaut]

Great to see that math all in one place, since I’m not a physicist. I’m sure that a successful aneutronic fusion program would lead to a lot more people looking to find more boron. But in any event, a FF used as a desalination plant can recover boron from its waste stream. A breeder reactor in a good way, for a change. I’m not worried about running out of fuel.

[zapkitty]

MTd2 wrote:
…
So, we would have, at the very best, 20 years to finish all boron.

I hope I am wrong…

The researcher’s figures are somewhat different… 🙂

https://focusfusion.org/index.php/forums/viewreply/229/

Boron is not in short supply. About 500,000 tons are produce per year for a price of about $700/ton. Since each GW of focus fusion power takes a ton per year of boron, the entire current world production of energy would only consume about 10,000 tons per year. If, in the far future, we ran short, we can get boron from seawater. Total resources would last billions of years at current rates.

[MTd2]

He uses 1MWyear=1KG of boron. The world consumption is 35TW, so it means 35 thousand tons of borons, 1/3 of what I estimated. That means 30% of the fusioned energy turned into useful energy, For a Q=1.6, it would mean an efficiency of 80% (1.3/1.8). Isn`t that a bit high?

[dennisp]

Let’s assume you’re right. That’s 20 years if the world runs entirely on FF. Since FF is so cheap I’d expect the transition to happen pretty quickly, but it won’t be instantaneous. Systems like hydroelectric dams with high sunk costs but low operating costs will probably keep going for a while. It will also take a while to convert transportation.

So let’s say based on known reserves we have 30 years from the time we get the first commercial reactor. That’s a fair amount of time to get new sources of boron.

The first thing we’ll do is look for new reserves in the ground. Seawater has already been mentioned. Beyond that, asteroid mining is easily economical when you can get to space for $30/lb. The solar system has millions of times the resources of the Earth; once we can get out there cheaply our resource issues will go away for a long time to come.

[Aeronaut]

dennisp wrote: Beyond that, asteroid mining is easily economical when you can get to space for $30/lb. The solar system has millions of times the resources of the Earth; once we can get out there cheaply our resource issues will go away for a long time to come.

Wonder what we’re going to use for landfills out there?

[vansig]

MTd2 wrote: 10 thousand tones of Boron = 10^10g

10^10g has 6×10^23×10^10×10^-1 = 6×10^32 atoms of boron, since 1 mol of boron has aprox. 10g

An atom of boron yields 8MeV, so, the total output is 4.8×10^40eV. In joules, it would give 8*10^21J

The net output of that is around 10%, for commercial use, so, it means 10^21J, aprox.

The total consumption of energy of the world is 35TW or 3.5*10^13W which means 10^22J every year. To match this production, around 100thousand tones every of boron should be used.

The known commercial reserves of borate BO3(-3) are 10 milllion tons, which gives at best 1 – 2millions tons of pure boron.

So, we would have, at the very best, 20 years to finish all boron.

I hope I am wrong…

yes. here are two problems with your calculation. one is:

35 TW = 35 x 10^12 J/s;
x 86400 s/day x 365.25 days/year = 1.1 x 10^21 J, only. ( one tenth of your number. )

and the second problem is that the figure of 35 TW is bonkers.

EIA projection for future electricity demand is ” 25.0 trillion kilowatthours in 2020 and 35.2 trillion kilowatthours in 2035.”
— http://www.eia.doe.gov/oiaf/ieo/highlights.html

1 kW h = 3.6 MJ

x 25.0 x10^12 = 9 x 10^19 J per annum in 2020;

and 1.267 x 10^20 J per annum in 2035.

that’s now on the order of a hundredth of your number. please check your facts and reference sources.

third, please use a system efficiency of 50%, which is approximately the number we’d get if we used steam turbines to recover the energy.

and finally, consider co-generation as a possible use. waste heat, that’s marginal for steam, is still pretty good for bathing. these generators will be small, and serve the needs of local communities.. like individual buildings in New York City, for example.

[dennisp]

Vansig it looks like you’re talking projected electricity usage, I think MTd2 is talking total energy consumption, which includes oil and natural gas for transportation and heating…Wikipedia puts that a good bit lower at 15 TW. Their source is a spreadsheet published by BP.

http://en.wikipedia.org/wiki/World_energy_resources_and_consumption

If both numbers are correct then I’m surprised that electricity is such a small portion of the total. Maybe something’s still off somewhere.

I’m not sure you guys are talking about the same thing on FF efficiency either. Eg., laser fusion requires a steam cycle, so call it 50% efficient at recovering the output. But there’s also the power required to fire the laser. FF has a substantial power input as well.

If the researcher is correct, we just need 15,000 tons per year at current rates. If MTd2 is correct that his power output estimate is “a bit high,” call it 30K tons. But if energy is 50 times cheaper, we’ll use a lot more of it. We’ll desalinate lots of seawater, grow crops underground, holiday in orbiting hotels, and pull excess CO2 from the atmosphere. It’ll be the biggest economic boom in history, and it sure will use up some boron.

So we probably shouldn’t wait too long before investigating new boron sources. How much can we extract from a desalination plant? How much can we easily get from asteroids or the Moon? Etc.

[vansig]

dennisp wrote:
I’m not sure you guys are talking about the same thing on FF efficiency either. Eg., laser fusion requires a steam cycle, so call it 50% efficient at recovering the output. But there’s also the power required to fire the laser. FF has a substantial power input as well.

50% system efficiency was the figure Eric gave.

it should be reasonable to expect conversion efficiency of the exit beam to be similar to a high-voltage transformer. Those are usually >90%. even if you consume all of that for FF’s power input, you can recover a substantial amount of heat for running a steam cycle.

[shawn]

The thing about these types of speculative calculations is they do not account for improvements in design.
They merely take existing data and produce a figure we ought to be anxious over.
Even if the figures are somehow accurate and translate into 50 to 100 yrs of energy production, just factor in the innovation aspect which is exploding exponentially with our population increase and related factors.
What is going on these days is amazing.
Now if we could tweak commerce a bit to unleash the dynamo………..
what a world we would see.

[Author]

Posts