Energy • Hacker News Board

Re: Energy

#161

Post by kpennell » Tue, Jun 30, 2015, 1:33 AM UTC

donttrustatoms wrote: post #126

sgk284 wrote: post #13

Slightly off-topic, but going to UPower's site shows nothing but a somewhat sparse wintery forest. Perhaps I've too much sci-fi on the brain, but it made me think of a nuclear winter.

Haha, wow. :) Thanks for the comment. It was meant to signify the communities in the far north or arctic that currently are reliant on very expensive and dirty diesel... Our webpage is under construction probably to be put up in about a week. You can definitely feel free to ask any questions and would appreciate your thoughts on the new one.

cool of you to respond!

Re: Energy

#162

Post by hypertexthero » Tue, Jun 30, 2015, 1:34 AM UTC

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/2015/04/20/artificial-photosyn...

Re: Energy

#163

Post by zbravo » Tue, Jun 30, 2015, 1:52 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…

http://solarfuelshub.org/

Re: Energy

#164

Post by abalone » Tue, Jun 30, 2015, 1:53 AM UTC

> 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 sites around the world that remain hazardous for 100 years, instead of centrally storing it?

Plus I've read that although these mini reactors are not directly producing material that could be used in a dirty bomb, that they could be converted to do so if they fell into the wrong hands. I may be oversimplifying here, but the question again is what is the public risk of distributing atomic fuels and reactors in a manner that makes them much less secure? Would this make them more susceptible to "war hacking" and could this be the mini-reactor equivalent of a nuclear disaster?

Nuclear costs have always been about the long term public costs, not the short term $/kWh.

This is before we even consider the taxpayer cost that's gone into nuclear tech development. I wonder if there will be more public money needed to take this tech to market, even if the test reactors bear fruit.

Re: Energy

#165

Post by jddw » Tue, Jun 30, 2015, 1:55 AM UTC

DennisP wrote: post #115

mrbabbage wrote: post #110

Earlier quoted context omitted.

> nuclear backup That wouldn't work with current nuclear reactors, whose startup / shutdown sequences take hours. Typically, the grid operator runs nuclear plants at nearly 100% 24/7 (so called "baseload") due to this. I'd be curious how truck-sized reactors work and whether or not you could operate them as load-followers rather than baseload. That would make them extremely attractive for replacing natural gas peaker…

My point mainly is that if there's more demand when solar produces more energy, then you can pretty much run the nuclear plants all the time and get a decent balance. But I suspect the small reactors will be more flexible. Molten salt reactors are supposed to load-follow automatically with a lag of thirty seconds or so. (And of course with small fusion reactors it wouldn't be a problem at all.)

You're right. It is also a common misconception that nuclear reactors cannot load follow, they can:

http://ansnuclearcafe.org/2013/02/14/responding-to-system-de...

One of the main limitations is the stress it puts on the fuel.

Many advanced reactors overcome these limits, and if financially incentivized, they will definitely load follow. On top of that, the UPower reactor has a thermal transport time constant nearly 10 times that of other reactors, and its fuel is immune to the shocks that bother LWRs. In fact, the same type of fuel was used in a research reactor and would be ramped in power from 5 watts to 150 billion watts in less than 50 millionths of a second. That puts a lot of stress on fuel, yet this fuel kept its stride without breaking a sweat.

This reactor is built like a tank, and is designed to be quite resilient and flexible. It can definitely load follow to support a renewable heavy grid system. In fact it's been considered for use as a grid stabilizer at substations because of these abilities.

Re: Energy

#166

Post by justonepost » Tue, Jun 30, 2015, 1:56 AM UTC

donttrustatoms wrote: post #131

beat wrote: post #84

Earlier quoted context omitted.

So how small a reactor? And what sort of cost, what sort of setup time, what sort of safety constraints (ie, current reactors are generally water-cooled and need access to large bodies of water)? It's possible to trim the cost of reactors from the billions to the millions, maybe, but how many millions? Certainly, solar with batteries is a lot more expensive - but to my point, startup cost is low. Latency, or bandwidt…

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.

Re: Energy

#167

Post by beat » Tue, Jun 30, 2015, 2:00 AM UTC

nosuchthing wrote: post #124

DennisP wrote: post #115

Earlier quoted context omitted.

My point mainly is that if there's more demand when solar produces more energy, then you can pretty much run the nuclear plants all the time and get a decent balance. But I suspect the small reactors will be more flexible. Molten salt reactors are supposed to load-follow automatically with a lag of thirty seconds or so. (And of course with small fusion reactors it wouldn't be a problem at all.)

Solar generation is less predictable, and the grid needs an energy source that is capable of quickly adjusting to the current fluctuation in demand of consumers.

That's where the batteries come in. To continue the software metaphors, batteries provide caching, and the cache is tunable for cost and performance. This wasn't viable a decade ago, but with the advances in solar/wind cost/performance, and the advances in battery cost/performance, it's really becoming a powerful option.

Re: Energy

#168

Post by beat » Tue, Jun 30, 2015, 2:02 AM UTC

DennisP wrote: post #109

beat wrote: post #84

Earlier quoted context omitted.

So how small a reactor? And what sort of cost, what sort of setup time, what sort of safety constraints (ie, current reactors are generally water-cooled and need access to large bodies of water)? It's possible to trim the cost of reactors from the billions to the millions, maybe, but how many millions? Certainly, solar with batteries is a lot more expensive - but to my point, startup cost is low. Latency, or bandwidt…

Startup cost for solar is not all that amazingly cheap per watt, and if you include batteries it's probably more than nuclear. UPower's design doesn't require a large body of water: http://spectrum.ieee.org/energywise/energy/nuclear/startup-d... For setup you deliver it with a truck and bury it. Other modular nuclear designs are a bit bigger but still in the range of small natural gas plants, which are competing quit…

Solar scales MUCH more fine-grained. There isn't a convenient source for 10kw nuclear power, and there probably never will be, but it's easy to build solar at that scale.

Re: Energy

#169

Post by shanev » Tue, Jun 30, 2015, 2:07 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…

Janine Benyus talks about this in her TED talk Biomimicry in action: http://www.ted.com/talks/janine_benyus_biomimicry_in_action.

We should look to nature before designing things since it may have already solved the problem for us. Future technology should also be designed to gracefully degrade like nature, otherwise we're just replacing one problem with another.

Re: Energy

#170

Post by mikeash » Tue, Jun 30, 2015, 2:12 AM UTC

throwaway24242 wrote: post #146

mikeash wrote: post #57

Earlier quoted context omitted.

What's wrong with copying the solution used for all the other toxic waste modern industry produces? We have no working long term solution for storing arsenic, but people mostly seem fine with "just dispose of it in a way where it doesn't leech into the groundwater" and not the crazy restrictions everyone wants to put on nuclear waste storage.

Sry, that is a terrible argument. You are saying that we do not have to worry about nuclear waste, because we currently do not worry about other waste.

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 then why should we require that nuclear waste and only nuclear waste be solved for all time before nuclear power can be used?