Energy • Hacker News Board

Re: Energy

#171

Post by jddw » Tue, Jun 30, 2015, 2:13 AM UTC

hypertexthero wrote: post #162

Recently watched Cosmos Episode 6 where Neil deGrasse Tyson speaks of photosynthesis and how all our energy problems would be solved if we were able to learn the 'trade secrets' of how plants do it. This makes a lot of sense. Can anyone point out current research on this field? I don't seem to hear much about it. Edit: Just found this after searching #photosynthesis in Twitter: http://www.huffingtonpost.com/2015/04/2…

There are neat ways to make sunlight into fuel, but it's about what form that energy takes. If it is a fuel that needs to be burned - in the case of sugars from photosynthesis - we already do this by burning wood.

I think Cosmos missed a really important lesson which is that the fuels at our disposal are all a function of time and distance. The longer a fuel source has been building, and the less distance it has to travel to be useful to us, the more valuable it may be. The sun is a result of billions of years of the shape-shifting games between mass and energy, all driven by gravity. The fusion energy produced in the sun then has to travel 93 million miles to us to be useful. The food chain harnesses this energy and accumulates it over time, and after hundreds of millions of years much of that energy has been sequestered into fossil fuels. While there is a tremendous amount of power emanating from the sun, it has to go a long way or accumulate for a long time to be useful to us. Nuclear fuel sources on the other hand bring the billions of years of nucleus building that previous generations of stars did for us to our door step. The parent stars of our sun produced heavy actinides like uranium or thorium, as well as the abundant light elements like deuterium, helium, and boron, and then scattering them across the cosmos along with leftover hydrogen in brilliant novae and supernovae. In our case, many of these elements were in the stardust that formed earth, and are here beneath our feet and above our heads.

Solar, wind, and nuclear will dominate the 22nd century, but we need both, and they do and can play well together. They just need to be treated and respected equally.

Re: Energy

#172

Post by Retric » Tue, Jun 30, 2015, 2:18 AM UTC

jddw wrote: post #171

hypertexthero wrote: post #162

Recently watched Cosmos Episode 6 where Neil deGrasse Tyson speaks of photosynthesis and how all our energy problems would be solved if we were able to learn the 'trade secrets' of how plants do it. This makes a lot of sense. Can anyone point out current research on this field? I don't seem to hear much about it. Edit: Just found this after searching #photosynthesis in Twitter: http://www.huffingtonpost.com/2015/04/2…

There are neat ways to make sunlight into fuel, but it's about what form that energy takes. If it is a fuel that needs to be burned - in the case of sugars from photosynthesis - we already do this by burning wood. I think Cosmos missed a really important lesson which is that the fuels at our disposal are all a function of time and distance. The longer a fuel source has been building, and the less distance it has to t…

Heavy elements that allow for Fission are products of supernova which are really more a question of minutes than years. With the vast majority being created in under 2 minutes after the reaction starts.

PS: https://what-if.xkcd.com/73/

Which of the following would be brighter, in terms of the amount of energy delivered to your retina: A supernova, seen from as far away as the Sun is from the Earth, or The detonation of a hydrogen bomb pressed against your eyeball?

A: Applying the physicist rule of thumb suggests that the supernova is brighter. And indeed, it is ... by nine orders of magnitude.

Re: Energy

#173

Post by sunstone » Tue, Jun 30, 2015, 2:20 AM UTC

Apparently the crust of the earth is floating on huge nuclear energy generator. I guess it's a materials problem to tap into that?

Re: Energy

#174

Post by oska » Tue, Jun 30, 2015, 2:22 AM UTC

justonepost wrote: post #166

donttrustatoms wrote: post #131

Earlier quoted context omitted.

You're exactly right, and that's what we designed for with UPower. I would have written the exact same thing when we began talking about doing something in nuclear 5 years ago. Too many reactors are designed without the market or financing in mind. We decided on the simplest possible reactor optimized to a size useful to a market in dire need- just MW scale. It has no pumps, no water in the reactor, and builds upon a…

The problem with anything nuclear is insurance. The only way reactors got insured was because Uncle Sam underwrote them.

Indeed. What insurer could have covered the estimated 137 billion dollar hit [1] from the Fukushima disaster? The Japanese government has had to step in, to the very real financial detriment of its people and their nation.

[1] http://www.bloomberg.com/news/articles/2012-11-07/fukushima-...

Re: Energy

#175

Post by jddw » Tue, Jun 30, 2015, 2:29 AM UTC

sskates wrote: post #42

chinathrow wrote: post #39

Earlier quoted context omitted.

> On paper it seems like a great energy source. On paper the waste issue is still not solved. And the risks are still large (yes I know, coal, gas and oil has it's drawbacks too).

Not sure about waste, can someone else here speak to that? Also deaths per unit energy are incredibly low relative to other sources.

The UPower design is waste negative so it can convert the entire planet's spent nuclear fuel and depleted uranium stockpiles into enough energy to power the globe for about 500 years. All while leaving behind a waste stream that decays to be less radioactive than the ground beneath your feet in a few hundred years. If we buried it in Paul Revere's basement when it was built, people could see it and touch it today without any exposure above background. Not to mention it is also fuel agnostic so it can run on thorium as well.

It's also important to highlight that the UPower design can consume the entire actinide vector because it uses fast neutrons. A lot of the longer lived actinides cannot be fissioned or transmuted effectively by thermal neutrons so they just build up.

We like to say we are the ultimate disposal, and can take anything, including the waste from other waste consumers.

Re: Energy

#176

Post by mooreds » Tue, Jun 30, 2015, 2:31 AM UTC

abalone wrote: post #164

> terrestrial-based atomic energy... has major advantages when it comes to cost Are we talking public cost? Because that's all that matters. So far the public cost of nuclear power has been extraordinary, due to accidents and waste. I understand that some of these startups aim to process existing waste in relatively small distributed reactors but what is the public cost of spreading a bunch of "mini" toxic waste site…

Anyone thinking about this needs to watch "Into Eternity", a movie about the Finnish nuclear waste repository: http://www.intoeternitythemovie.com/

"In Finland the world’s first permanent repository is being hewn out of solid rock - a huge system of underground tunnels - that must last 100,000 years as this is how long the waste remains hazardous."

It was eye opening.

Re: Energy

#177

Post by kolbe » Tue, Jun 30, 2015, 2:34 AM UTC

> By combining our years of experience in fusion, newly available electronics technologies, and a revolutionary design using cutting-edge physics, Helion is making a fusion engine 1,000 times smaller, over 500 times cheaper, and realizable 10 time faster than other projects.

What?!? I certainly appreciate the ambition, but humanity has spent seven decades and at least hundreds of billions of dollars on this very same project. What in the world is this tiny startup doing with a $5mm grant that is so easy and cheap that could possibly lead to that kind of breakthrough in fusion energy?

Re: Energy

#178

Post by lutorm » Tue, Jun 30, 2015, 2:35 AM UTC

jddw wrote: post #171

hypertexthero wrote: post #162

Recently watched Cosmos Episode 6 where Neil deGrasse Tyson speaks of photosynthesis and how all our energy problems would be solved if we were able to learn the 'trade secrets' of how plants do it. This makes a lot of sense. Can anyone point out current research on this field? I don't seem to hear much about it. Edit: Just found this after searching #photosynthesis in Twitter: http://www.huffingtonpost.com/2015/04/2…

There are neat ways to make sunlight into fuel, but it's about what form that energy takes. If it is a fuel that needs to be burned - in the case of sugars from photosynthesis - we already do this by burning wood. I think Cosmos missed a really important lesson which is that the fuels at our disposal are all a function of time and distance. The longer a fuel source has been building, and the less distance it has to t…

Why does it matter how far away the Sun is? It's the amount of energy available to us here that matters. And it doesn't have to accumulate at all, the instantaneous energy flux is plenty high for our needs.

Re: Energy

#179

Post by ageofwant » Tue, Jun 30, 2015, 2:36 AM UTC

mooreds wrote: post #176

abalone wrote: post #164

> terrestrial-based atomic energy... has major advantages when it comes to cost Are we talking public cost? Because that's all that matters. So far the public cost of nuclear power has been extraordinary, due to accidents and waste. I understand that some of these startups aim to process existing waste in relatively small distributed reactors but what is the public cost of spreading a bunch of "mini" toxic waste site…

Anyone thinking about this needs to watch "Into Eternity", a movie about the Finnish nuclear waste repository: http://www.intoeternitythemovie.com/ "In Finland the world’s first permanent repository is being hewn out of solid rock - a huge system of underground tunnels - that must last 100,000 years as this is how long the waste remains hazardous." It was eye opening.

That's just nonsense. Forth generation breeder reactors burn their own waste to something close to irrelevant. Existing "Waste" should be continually burned and the energy used to sequester C02 from the atmosphere, for example, not uselessly stored in a bunker. There is no reason for that facility to exist.

Re: Energy

#180

Post by jddw » Tue, Jun 30, 2015, 2:36 AM UTC

jarvist wrote: post #49

mikeash wrote: post #34

Earlier quoted context omitted.

Much of the waste problem can be solved by using reactors designed to use the waste as fuel. This isn't currently done, but there's no big technical reason it couldn't be. For what remains after that, well, there's nothing particularly wrong with sticking it in some extremely sturdy armored containers, sticking the containers in a shed, surrounding the shed with a razor-wire fence, and stationing a couple of guards a…

> using reactors designed to use the waste as fuel What do you mean? The waste is full of nuclear poisons (a technical term, isotopes that stop fission by neutron capture). Reusing it means reprocessing to extract the Plutonium, which is burnable in a reactor (particularly as MOX). The chemistry required for this is pretty messy, and the radioactive environment (fuel from a power station is very 'hot' radioactively s…

There's a lot of energy in those 112 tonnes, but you really need a fast reactor to burn it. Plutonium is a lot easier to tackle in a fast reactor than a thermal reactor.

Also, UPower can use the waste without putting it through a chemical separations process. In fact you can just take the SNF grind it up, and dump it into the UPower reactor alongside the rest of the fuel. It actually makes a pretty good fuel that way.