Energy • Hacker News Board

Re: Energy

#251

Post by stillsut » Tue, Jun 30, 2015, 12:37 PM UTC

The killer app for these modular reactors is to scale with the same footprint: If you have the infrastructure to house one of these boxcars, for the town's first factory, why not 10 boxcars on the same site once the town grows in population.

That's what you can't do with solar - with solar you already have a big footprint to power that first factory, and your footprint increases proportional to power use. 21 century calls for scaling roughly 20x = 2x (population growth) * 10x (rise in developing worlds livining standards). I don't want 20x solar footprint.

Re: Energy

#252

Post by DennisP » Tue, Jun 30, 2015, 12:49 PM UTC

kolbe wrote: post #177

> 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…

Helion isn't the only small fusion startup. Others include General Fusion, which has investment from Jeff Bezos, and Tri-Alpha, which has over $150 million, including from Paul Allen and Goldman Sachs.

Fusion advanced exponentially from 1970 to 2000, at about the pace of Moore's Law. Then governments decided to put most of their fusion money into a giant, poorly-managed construction project in France. But we're not that far off, and in those seven decades we've learned a lot about plasma physics, gotten much better computers for plasma simulations, and developed all sorts of other enabling technologies.

Re: Energy

#253

Post by DennisP » Tue, Jun 30, 2015, 12:57 PM UTC

ocschwar wrote: post #184

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's a more efficient way to do that. Use TCP/IP to synchronize the consumption of power with its production. Solar and wind are pretty awesome if you can schedule around them. And most of our power consumption is amenable to it.

So turn everything off when the wind's not blowing and the sun's not shining? That doesn't sound ideal to me.

Re: Energy

#254

Post by DennisP » Tue, Jun 30, 2015, 1:01 PM UTC

legulere wrote: post #242

One problem I see with nuclear power is that it goes the very inefficient way over heat. The prices in the building industry are rising so much that it already is unprofitable to build nuclear power in the west today. (When Hinkley Point C will start producing energy it will have a higher feed in tariff than photovoltaics: https://en.wikipedia.org/wiki/Hinkley_Point_C_nuclear_power_... ) I don't see any future for nu…

Then you'll like Helion, which produces high-energy charged particles and doesn't use a thermal cycle.

Neither of the ycombinator companies produces long-term waste.

Re: Energy

#255

Post by DennisP » Tue, Jun 30, 2015, 1:10 PM UTC

chinathrow wrote: post #245

jddw wrote: post #214

Earlier quoted context omitted.

First, the reactors are consuming the fuel while deployed, but no waste is stored at the sites. It is stored centrally so there are a few centralized sites that hold the waste for a few hundred years. After which you could make things out of the material and use them around your home without issue. The reactors cannot be deviated for nefarious purposes. And the materials are not less secure. The materials are being c…

All your statements seems to good to be true. Can you back them up with some facts?

It's a 1MW reactor. That's a thousand times smaller than conventional nuclear reactors. It doesn't seem unlikely that it could be passively cooled.

For the rest, a great source is the book Plentiful Energy, by the chief scientists of another small fast-reactor project at Argonne. For that reactor, the fuel is a mix of plutonium isotopes which can't be used for bombs and are much more difficult to purify than natural uranium ore. The waste goes back to the radioactivity of the original ore in a couple centuries.

http://www.amazon.com/Plentiful-Energy-technology-scientific...

Re: Energy

#256

Post by DennisP » Tue, Jun 30, 2015, 1:15 PM UTC

lutorm wrote: post #178

jddw wrote: post #171

Earlier quoted context omitted.

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.

Except for the darn planet getting in the way half the time.

Re: Energy

#257

Post by chinathrow » Tue, Jun 30, 2015, 1:29 PM UTC

TeMPOraL wrote: post #238

mikeash wrote: post #170

Earlier quoted context omitted.

I'm saying that nuclear waste is treated with far more paranoia than it deserves, as illustrated by how we dispose of other waste much less carefully, even though it's just as dangerous. And mostly successfully, too. That doesn't mean that it's something to be ignored, or that current methods of waste disposal are perfect, but if we aren't shutting down the entire chemical industry (for example) over this problem the…

Exactly. Nuclear waste is one of the best types of toxic waste we've ever seen. It's relatively compact, still able to be used as fuel in the future, there isn't much of it, and it makes itself harmless with just passage of time; no need to treat it with anything.

"Lot's of time".

Re: Energy

#258

Post by Retric » Tue, Jun 30, 2015, 2:11 PM UTC

donttrustatoms wrote: post #129

Retric wrote: post #72

Earlier quoted context omitted.

As a sanity check, the earth gets ~1366 W/m2 * (6,371 km) ^2 * pi = 1.7e17 watts * 24h/day * 365.2425day/year ~= 1.5e21Wh/year ~= 1,500,000,000 terawatt hours/year. Humans use 155,505 terawatt-hour / year or ~ 1/10,000th of that much energy. ( https://en.wikipedia.org/wiki/World_energy_consumption ) Further, it's all (99.99%) going to get released so net impact is going to be very local. PS: In the end the real chang…

Hurricanes also produce Terawatts of energy. The question is the way the energy is turned into electricity, and how it's stored or backed up because an economy requires reliable electricity I'm a supporter of solar, and trying to get it on my house. But I also did some back of the envelope calculations that showed, just if we had enough Powerwalls to backup US peak demand for one hour it would require 10x the global…

20,000km2 sounds huge but:

The US currently uses 40% of the 84 million acres or 340,000km2 crop for ethanol production which is arguably pointless. So, if we swapped just corn ethanol for solar cells we would have 6 times more land area than the entire state of Massachusetts covered in solar cells (135,000km2). And if we feel ethanol is really necessary we only need 8% of the total corn crop leaving 32% for corn ethanol.

If this still seems like a huge issue the soybean crop is far larger. http://www.epa.gov/oecaagct/ag101/cropmajor.html

PS: As to storage, we don't need 100% solar wind and hydro can make a huge difference. Pumped storage is also far cheaper at scale; it's just impractical when scaled down to home use.

Re: Energy

#259

Post by TeMPOraL » Tue, Jun 30, 2015, 2:13 PM UTC

chinathrow wrote: post #257

TeMPOraL wrote: post #238

Earlier quoted context omitted.

Exactly. Nuclear waste is one of the best types of toxic waste we've ever seen. It's relatively compact, still able to be used as fuel in the future, there isn't much of it, and it makes itself harmless with just passage of time; no need to treat it with anything.

"Lot's of time".

Much less than waiting for protons to decay, which you need for the waste 'mikeash was talking about that we're so casual about storing safely.

Re: Energy

#260

Post by pjc50 » Tue, Jun 30, 2015, 2:17 PM UTC

oska wrote: post #174

justonepost wrote: post #166

Earlier quoted context omitted.

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-...

Well, it's cheaper than Greece.

(Nuclear reactors have the same "too big to fail" problem as the banking system: the expected value is positive, but the worst-case is a huge open ended liability and toxic asset)