RandomOne

BBC NEWS | Science & Environment | Giant laser experiment powers up

This is the stuff of science fiction.

If it works... we could have an energy source capable of powering a starship

nornerator

While I agree that this is a huge step forward in science, technology, and energy creation, it begs a question. We already have a huge fusion reactor which operates safely without any maintenance or personnel, but for some reason we cannot harvest this energy properly. The Sun! It provides more than enough power in sheer wattage to power everything in our civilization and much more. Why don't we harvest the suns energy? That way we don't have to risk any runaway fusion accidents

IGemini

Quite a few reasons.


Solar cells are really expensive to produce. Cost-effectiveness isn't seen for 5-10 years after necessary construction of any solar setup (in ideal circumstances), if not more. Plus, solar power is only really viable in areas with access to a lot of direct sunlight and a minimum of cloud cover. Ideally, these areas are in the southern parts of the US, mostly in desert regions. There are only three stations currently active in the US, the rest will only be in states like California, Arizona, and Nevada. Power distribution is only so effective to a degree. Stratospherical solar collection would almost be more efficient, since almost half of all solar radiation is reflected into space before it hits terra firma.

I'm not sure how likely "runaway fusion accidents" would be...it's not like fission that's much harder to control. It only takes one stray neutron to cause a runaway reaction in a uranium reactor. But with fusion, you can only use as much product as is put into the reactor. Deuterium itself is a naturally-occuring particle (1 part per 6,500), but tritium for the purposes of fusion as a terrestrial power source is only formed by artificial means, and decays quite rapidly.

nornerator

While this answers the question of why current solar power technologies are not heavily invested in, clearly there is a disconnect between how much energy is coming from the sun and how much energy we need to power our civilization.

The amount of sheer power from the sun that hits the earth is ~1,353Watts per square meter.

The amount of energy needed to power the earth is 1.6 x 10^13 W

The total amount of power received by the sun on the earths surface is 8.9x10^15 W, nearly 600 times as much power as is required by all human civilization.

Its not that the power source is inadequate, simply our technology.

Not to mention the possibility of building a huge solar array in space around part of the sun as part of a Dyson sphere. The energy could be beamed back to earth.

I am all for fusion power, don't get me wrong. It just seems like such a waste that we already have such a large fusion reactor sending out massive amounts of power that simply is not being tapped.

World energy resources and consumption - Wikipedia, the free encyclopedia

RandomOne

I agree we should be harnessing more power from the sun. That's one of the steps towards becoming a Class II civilization right?

We still need to be researching Portable fusion though. Fusion we can put on a spaceship and take with us. Fusion we can put on a base on one of jupiter's moons.

Yana Usdi

Another aspect to consider with the future of fusion is helium 3. It's pretty rare on earth but it's plentiful on the moon and it's one of the few things that might be worth mining to bring back down. Gold wouldn't be worth the transport costs but that might be.

An article on the subject from Wired was interesting.

Race to the Moon for Nuclear Fuel

ctwalrus

"To work, it must show that more energy can be extracted from the process than is required to initiate it."

omg
can anyone say holy grail

__________________
☮ ♥

RandomOne

It sounds like it would break the laws of thermodynamics. But think about a nuclear explosion, much more energy comes out of it than is put in (or more like we are tapping the real energy potential of the atoms in the reaction).

I think it is possible, but the main issue will be mass. I don't think their pellet of hydrogen ions will be enough to create a sustainable fusion source. the sun works because it is so massive that it's fusion can be caused by gravity. But given an infinite supply of hydrogen that they can keep feeding into the thing, and given that they get enough power out of it to keep running the laser beams plus a little extra, it would be an infinite energy source, no?

Here's hoping anyway.