Energy • Hacker News Board

Re: Energy

#111

Post by donttrustatoms » Mon, Jun 29, 2015, 9:39 PM UTC

andy_ppp wrote: post #26

Isn't decommissioning nuclear power plants still basically a huge bill underwritten by the tax payer? I'm not really sure about creating radioactive waste that has such huge half lives... From Wikipedia: Of particular concern in nuclear waste management are two long-lived fission products, Tc-99 (half-life 220,000 years) and I-129 (half-life 15.7 million years), which dominate spent fuel radioactivity after a few tho…

I am one of the UPower founders. There are two big stories here that most people don't know yet: 1) that a fast reactor can be waste-negative, I.e. transform existing waste to energy. 2) a fast reactor destroys the long lived waste- instead of trying to store waste for a hundred thousand years it's on the order of a hundred.

Both of these are critically important for existing waste but also having an emission free energy source with a closed fuel cycle. No other energy source is better than a hundred thousandth as energy dense and no other energy source could produce clean energy for its own recycling.

It's obviously just a cool technology but more than that it's amazing what that could mean for the environment and remote communities. Even for solar and wind materials mining, these remote mines generally have to burn tons and tons of diesel. That's what we are trying to fight.

Re: Energy

#112

Post by beat » Mon, Jun 29, 2015, 9:42 PM UTC

erobbins wrote: post #53

This is fantastic. Nuclear fission suffers from a hindenberg-type PR problem, where incidents from early design mistakes and poor choices color the opinions of people even though modern reactor designs are safe, efficient, and essentially clean other than small amounts of waste. I would love to work on a project like this.

It's not just a PR problem, though. It's a cost structure problem, and a grid problem. On the cost front, they're tremendously expensive. New tech and manufacturing processes might get the cost from the billions to the millions, but it's still very expensive.

On the grid front, nuclear is good for baseline, but not peak load. Most nuclear reactors can't just be flipped on and off with a switch, or even scale power quickly... they're more or less constant. So you still need a peak load system, which currently consists of gas plants - very expensive, since they're intermittent and offline most of the time.

Re: Energy

#113

Post by antaviana » Mon, Jun 29, 2015, 9:42 PM UTC

Eleutheria wrote: post #18

Distributed generation is where we should invest. Energy independence for the individual. Individual solar panels and batteries, personal windmills, personal reactors, etc. Imagine all the savings in infrastructure for energy transportation and reinvestment in other sectors. Imagine all the possibilities if people could switch their energy generation model as simple as buying a new product and installing it at home.…

Unless you live in Spain, where solar energy generation by individuals is taxed in a way that it is a lot cheaper to just buy energy from the grid. Investment in solar energy generation in Spain is one order of magnitude smaller than 10 years ago.

Your post-scarcity world will surely not include Spain.

Re: Energy

#114

Post by DennisP » Mon, Jun 29, 2015, 9:43 PM UTC

soulsurfer wrote: post #107

One important thing that nobody thinks about when discussing nuclear fission/fusion as energy source of the future, is that it is not climate neutral at all. Popular science tends to forget about that. In fact, nearly all of the energy budget on earth comes from the sun. There is natural fission and energy emission on earth, but you can see that as a background constant and the climate system on earth has adapted to…

Yes, there will be waste heat and that will add to the Earth's energy budget. But that's a tiny fraction of the heat trapped by excess greenhouse gases.

Deploying a bunch of black solar panels will also increase the Earth's energy budget, by absorbing more sunlight. But that's another insignificant effect.

Re: Energy

#115

Post by DennisP » Mon, Jun 29, 2015, 9:46 PM UTC

mrbabbage wrote: post #110

DennisP wrote: post #55

Earlier quoted context omitted.

Gigawatt-scale nuclear reactors take a long time. Ycombinator is investing in factory-produced reactors that fit in a truck. There are quite a few other companies working on small factory-produced reactors. Solar with batteries is a lot more expensive than solar alone. Solar is doing well right now with natural gas backup, but a lot of us would like to avoid fossil entirely. Solar with nuclear backup might be a great…

> 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.)

Re: Energy

#116

Post by DennisP » Mon, Jun 29, 2015, 9:48 PM UTC

donttrustatoms wrote: post #111

andy_ppp wrote: post #26

Isn't decommissioning nuclear power plants still basically a huge bill underwritten by the tax payer? I'm not really sure about creating radioactive waste that has such huge half lives... From Wikipedia: Of particular concern in nuclear waste management are two long-lived fission products, Tc-99 (half-life 220,000 years) and I-129 (half-life 15.7 million years), which dominate spent fuel radioactivity after a few tho…

I am one of the UPower founders. There are two big stories here that most people don't know yet: 1) that a fast reactor can be waste-negative, I.e. transform existing waste to energy. 2) a fast reactor destroys the long lived waste- instead of trying to store waste for a hundred thousand years it's on the order of a hundred. Both of these are critically important for existing waste but also having an emission free en…

UPower is a fast reactor? If so that's pretty encouraging!

Re: Energy

#117

Post by DennisP » Mon, Jun 29, 2015, 10:01 PM UTC

hackuser wrote: post #70

Years ago, the story I understood was that renewables couldn't scale up fast enough to sufficiently mitigate climate change, and nuclear was the only answer. Recently, I've read that renewables have scaled up much faster than expected. Does anyone know the current story? Can renewables scale up fast enough? Also, does the availability problem (i.e., renewables not being available when the sun/wind are not) prevent th…

Renewables still aren't fast enough by themselves, even with the most optimistic projections, according to engineers from Google's big renewables project: http://spectrum.ieee.org/energy/renewables/what-it-would-rea...

Availability is a problem. Right now we're mainly backing up renewables with fossil plants.

Most people really aren't getting what climate scientists are saying these days, which is that we have to cut emissions drastically in the very near future to avoid disaster. If we exceed +2C, or possibly even +1.5C, positive feedbacks will take the planet several degrees further even with no more emissions from us. Right now we're at +0.8C. Every ton of CO2 we emit takes 30 years to have its full effect on the temperature, considering direct effects alone, so we've got another 30 years of warming locked in already.

+4C or so might not sound like much but judging by geological history, the effects would include an enormous reduction in the amount of food we're able to produce.

Re: Energy

#118

Post by mikeyouse » Mon, Jun 29, 2015, 10:02 PM UTC

jsprogrammer wrote: post #23

benaiah wrote: post #21

Earlier quoted context omitted.

The hard data has been around for years, and is fairly easy to find. Not every blog post needs to have an accompanying statistical analysis.

So easy to find that it can't even be linked to on the web by two people that claim it exists?

I still think there are huge issues with nuclear that need to be solved but nothing Sam said was controversial;

Cost: http://www.eia.gov/forecasts/aeo/electricity_generation.cfm -- on an LCOE basis, Advanced Nuclear is cheaper than everything but natural gas and that's entirely due to CapEx costs to build new plants -- which are what the modular nuclear companies that Sam's joining are working on fixing.

Density: https://en.wikipedia.org/wiki/Energy_density#Energy_densitie...

Predictability: Can be assessed by the capacity factor of plants that are running, the EIA publishes monthly data; http://www.eia.gov/todayinenergy/detail.cfm?id=14611

Re: Energy

#119

Post by donttrustatoms » Mon, Jun 29, 2015, 10:05 PM UTC

Eleutheria wrote: post #18

Distributed generation is where we should invest. Energy independence for the individual. Individual solar panels and batteries, personal windmills, personal reactors, etc. Imagine all the savings in infrastructure for energy transportation and reinvestment in other sectors. Imagine all the possibilities if people could switch their energy generation model as simple as buying a new product and installing it at home.…

So true. That's exactly why this is so exciting. With a UPower generator, small communities or neighborhoods could have always on, emission free power for a decade.

and then, as you indicated, with enough clean power, individuals can create desalinated water or even extract water from air. They could cleanly power greenhouses even in the arctic. We could remove carbon from the air.

Re: Energy

#120

Post by donttrustatoms » Mon, Jun 29, 2015, 10:06 PM UTC

DennisP wrote: post #116

donttrustatoms wrote: post #111

Earlier quoted context omitted.

I am one of the UPower founders. There are two big stories here that most people don't know yet: 1) that a fast reactor can be waste-negative, I.e. transform existing waste to energy. 2) a fast reactor destroys the long lived waste- instead of trying to store waste for a hundred thousand years it's on the order of a hundred. Both of these are critically important for existing waste but also having an emission free en…

UPower is a fast reactor? If so that's pretty encouraging!

Yessir!