ohgodwhat posted:

Even in Arizona? Sure, a good chunk of people turn up the temperature when they're gone during the day, but nobody wants to come back to a 110 F house when they get back from work during the summer.

quote:

analysis by the Clean Air Task Force suggest that integration costs for solar and wind are likely to surge dramatically should renewables rise much above 20 or 30 percent of total electrical generation (see graph below).


(rehosted)

Costs of adding intermittent generation are likely to scale super-linearly with penetration, creating a deployment barrier. Some examples (various bases) in the figure: “Wind A” is the marginal cost per MWh of wind in ERCOT relative to the same index at 0% wind penetration. “Wind B” is the reciprocal of total system wind capacity factor in CAISO relative to 0% wind penetration (an indicator relative total system construction cost).“Wind C” is the number of annual CCGT start-ups in Ireland relative to 0% wind penetration (a proxy for system-wide O&M costs and emissions due to cycling).“PV” is the marginal cost per MWh of PV in ERCOT relative to the same index at 0% PV penetration. “RE Bundle” is the relative size of the US bulk transmission system (million MW-miles) due to bundled renewables (roughly ½ wind+solar) relative to 0% penetration.

Sources: CATF from Denholm & Hand, 2011 (Wind A); Hart et al, 2012 (Wind B); Troy et al, 2010 (Wind C); Denholm & Margolis, 2006 (PV); NREL, 2012 (RE Bundle).

Renaissance Robot posted:

I could have sworn we had the whole "[raw] output has exceeded ignition energy [but not even close to what we actually put in because our process is laughably inefficient]!" thing months ago.

Before that, I was under the impression that nobody seriously considers this reactor design to have potential for power generation because it can't be scaled up and there's no way to insert fuel/remove waste without turning it off.

Renaissance Robot posted:

I could have sworn we had the whole "[raw] output has exceeded ignition energy [but not even close to what we actually put in because our process is laughably inefficient]!" thing months ago. Before that, I was under the impression that nobody seriously considers this reactor design to have potential for power generation because it can't be scaled up and there's no way to insert fuel/remove waste without turning it off.

ShadowHawk posted:

I have a possibly stupid question about geothermal: could it potentially prevent volcanic eruptions?

As I understand it volcanoes are a massive source of carbon emissions (amid other obvious problems). They also occur where the earth's crust is the thinnest, which is precisely where it's easiest to drill geothermal energy wells.

Could a reasonable number of geothermal wells over a reasonably long period of time pull enough energy out of a hotspot to prevent (or reduce) the impact of a volcano? Are they even comparable in terms of orders of magnitude?

Pander posted:

I sincerely doubt it. Some volcanic eruptions are triggered by earthquakes, which geothermal would have no effect with. Besides that, I think the energy in volcanic eruptions is many many orders of magnitude larger than geothermal pulls out from. There's also a lot more potentially active volcanoes than there are viable geothermal sites. You wouldn't just try to install a lot of infrastructure on Pinatubo, for instance.

Renaissance Robot posted:

I could have sworn we had the whole "[raw] output has exceeded ignition energy [but not even close to what we actually put in because our process is laughably inefficient]!" thing months ago.

Before that, I was under the impression that nobody seriously considers this reactor design to have potential for power generation because it can't be scaled up and there's no way to insert fuel/remove waste without turning it off.

Baronjutter posted:

Other than political reasons why is so much being invested in fusion over something far more practical like thorium? Why not refine nuclear technology we know works vs much harder and potentially impossible goal of practical fusion?

Pander posted:

Calling fusion a physics problem is calling the ability for humans to flap their arms and fly a biology problem.

QuarkJets posted:

Uh, no, it's not at all like that.

Dusseldorf posted:

I would guess that you could find a number of well respected physicists who think that Fusion power is a tractable problem.

Pander posted:

Why not? Give us enough time with genetic manipulation and we'll get our drat bat wings within 100 years.

amanasleep posted:

In 2012 they generated the 1.8 Billion degree temperatures necessary to ignite pb11 fuel, shattering previous DPF records.

quote:

Although there have been a few proposals for fusion reactors employing plasmas far out of thermodynamic equilibrium (such as migma and inertial-electrostatic confinement), there has never been a broad, systematic study of the entire possible range of such devices. This research fills that gap by deriving fundamental power limitations which apply to virtually any possible type of fusion reactor that uses a grossly nonequilibrium plasma. Two main categories of nonequilibrium plasmas are considered: (1) systems in which the electrons and/or fuel ions possess a significantly non-Maxwellian velocity distribution, and (2) systems in which at least two particle species, such as electrons and ions or two different species of fuel ions, are at radically different mean energies. These types of plasmas would be of particular interest for overcoming bremsstrahlung radiation losses from advanced aneutronic fuels (e.g. ^3He-^3He, p-^{11}B, and p- ^6Li) or for reducing the number of D-D side reactions in D-^3He plasmas. Analytical Fokker-Planck calculations are used to determine accurately the minimum recirculating power that must be extracted from undesirable regions of the plasma's phase space and reinjected into the proper regions of the phase space in order to counteract the effects of collisional scattering events and keep the plasma out of equilibrium. In virtually all cases, this minimum recirculating power is substantially larger than the fusion power, so barring the discovery of methods for recirculating the power at exceedingly high efficiencies, reactors employing plasmas not in thermodynamic equilibrium will not be able to produce net power. Consequently, the advanced aneutronic fuels cannot generate net power in any foreseeable reactor operating either in or out of equilibrium.

Phanatic posted:

The problem is that it doesn't look like pb11 fusion can actually generate net energy. This MIT paper is well-known and fairly devastating to such fusion schemes:

quote:

In this article we studied the feasibility of proton-boron (p11B) fusion in plasmoids produced by plasma pinch devices like plasma focus facility as commercially sources of energy. In plasmoids fusion power for 76 keV < Ti < 1,500 keV exceeds bremsstrahlung loss (W/Pb = 5.39). In such situation gain factor and the ratio of Te to Ti for a typical 150 kJ plasma focus will be 7.8 and 4.8 respectively. Also with considering the ion viscous heating effect W/Pb and Ti/Te will be 2.7 and 6 respectively. Strong magnetic field will reduces ion–electron collision rate due to quantization of electron orbits. While approximately there is no change in electron–ion collision rate, The effect of quantum magnetic field makes ions much hotter than electrons which enhances the fraction of fusion power to bremsstrahlung loss.

Pander posted:

The primary problem is that they essentially need what today would be considered magic to make fusion work as an energy producer. Cheap heat isn't the problem, it's cheap pressure to confine the fuel. The entire premise of fusion is recreating the sun, and we simply can't create the gravity well required to keep a fusion reaction self-sustaining like fission reactions are. Calling fusion a physics problem is calling the ability for humans to flap their arms and fly a biology problem.

Kaal posted:

FYI the study that we're talking about uses laser focusing rather than artificial gravity wells to keep the reaction self-sustaining. There's a bunch of different ideas about how to do it. I think that it's a surety that we'll eventually figure it out, whereas a winged human is physically impossible (because of weight) unless you radically change that nature of what a human is. I don't think that you're really giving fusion scientists a fair shake here.

Pander posted:

I've known too many fusion scientists. My U of Illinois fusion professor insisted there'd be a fusion reactor on Mars within 30 years in 2008. There were other fusion professors looking at interesting stuff (interesting semi-conductor development), but power generation via fusion at this particular juncture isn't a good focus for the public imagination. Selling "breakthroughs" when it's decades upon decades away when we have pressing energy problems right now is asinine and done entirely for PR/grants.

Pander posted:

I've known too many fusion scientists. My U of Illinois fusion professor insisted there'd be a fusion reactor on Mars within 30 years in 2008. There were other fusion professors looking at interesting stuff (interesting semi-conductor development), but power generation via fusion at this particular juncture isn't a good focus for the public imagination. Selling "breakthroughs" when it's decades upon decades away when we have pressing energy problems right now is asinine and done entirely for PR/grants.

amanasleep posted:

I think this is true of main line Tokamak/NIF/ITER efforts. They have huge funding and poor results over decades of work. Of the alternative approaches, almost none have any significant funding (many for good reason). Still, I think it's a bit much to claim that fusion research is a waste of resources compared to expenditures on other energy solutions. Fusion power in general is not a part of the public imagination, so I don't think there is any danger that somehow people are going to get sidetracked from whatever priorities you think they should have.

To be clear, I am not opposed to nuclear research and power development in a properly regulated environment. But I think a few fusion approaches have merit and I am convinced that there is nothing theoretically infeasible about fusion power development within the same time horizon of other alternative energy proposals.

Kaal posted:

I dunno about huge funding. They've been consistently moderately funded for the last 60 years, and the total spending is somewhere in the neighborhood of $30 billion, I believe. That's maybe $500 million per year, and that's considered pretty low compared to the scale of our energy problems and the kind of money we spend on other fields (i.e. the US has spent $600 billion in oil, coal and natural gas subsidies over that same time period). The US spent $5.2 billion on energy research last year, meaning that fusion research constitutes perhaps 10% of overall energy research spending (which itself is pretty low).

http://www.washingtonpost.com/blogs/wonkblog/wp/2013/04/09/three-charts-that-show-the-u-s-spends-too-little-on-energy-research/
http://focusfusion.org/index.php/site/reframe/wasteful
http://en.wikipedia.org/wiki/Energy_subsidies

Pander posted:

Why not? Give us enough time with genetic manipulation and we'll get our drat bat wings within 100 years.

GrumpyDoctor posted:

Just saw this on Facebook. The work is described in a two-part paper that I'm just getting into now.

Pander posted:

Looked at the infographic and that base article. "This has got to have a staggering number of assumptions" was the first thought that jumped to mind.

quote:

We estimate that 3,800,000 5 MW wind turbines, 49,000 300 MW concentrated solar plants, 40,000 300 MW solar PV power plants, 1.7 billion 3 kW rooftop PV systems, 5350 100 MW geothermal power plants, 270 new 1300 MW hydroelectric power plants, 720,000 0.75 MW wave devices, and 490,000 1 MW tidal turbines can power a 2030 WWS world that uses electricity and electrolytic hydrogen for all purposes.

Pander posted:

Looked at the infographic and that base article. "This has got to have a staggering number of assumptions" was the first thought that jumped to mind.

Pander posted:

Looked at the infographic and that base article. "This has got to have a staggering number of assumptions" was the first thought that jumped to mind.

quote:

We have assumed that all end uses that feasibly can be electrified use WWS power directly, and that the remaining end uses use WWS power indirectly in the form of electrolytic hydrogen (hydrogen produced by splitting water with WWS power).

quote:

As explained in Section 2 we assume that most uses of fossil fuels for heating/cooling can be replaced by electric heat pumps

quote:

For several reasons we do not consider nuclear energy (conventional fission, breeder reactors, or fusion) as a long-term global energy source. First, the growth of nuclear energy has historically increased the ability of nations to obtain or enrich uranium for nuclear weapons (Ullom, 1994)

quote:

Electric generator manufacturers will pursue parallel design and development paths to hedge against raw material pricing, with certain designs making the best economic sense depending upon the pricing of copper, steel and permanent magnets. Considering the recent volatility of sintered NdFeB pricing, there will be a strong economic motivation to develop generator designs either avoiding permanent magnets or using ferrite magnets with much lower and more stable pricing than NdFeB.

quote:

However, the world will not consume lithium reserves in an uncontrolled manner until, one day, the supply of lithium is exhausted. As demand grows the price will rise and this will spur the hunt for new sources of lithium, most likely from recycling.

Install Windows posted:

What I find really funny is the proposal only proposes to replace fossil fuels, but the ending thing never mentions nuclear anywhere. Are they saying we can just generate 20% less power flat out?

Jacobson posted:

Second, nuclear energy results in 9–25 times more carbon emissions than wind energy, in part due to emissions from uranium refining and transport and reactor construction (e.g., Lenzen, 2008; Sovacool, 2008)

Lenzen, 2008 posted:

The most popular reactor types, LWR and HWR, need between 0.1 and 0.3 kWhth, and on average about 0.2 kWhth for every kWh of electricity generated. These energy intensities translate into greenhouse gas intensities for LWR and HWR of between 10 and 130 g CO2-e/kWhel, with an average of 65 g CO2-e/kWhel.

While these greenhouse gases are expectedly lower than those of fossil technologies (typically 600–1200 g CO2-e/kWhel), they are higher than reported figures for wind turbines and hydroelectricity (around 15–25 g CO2-e/kWhel) and in the order of, or slightly lower than, solar photovoltaic or solar thermal power (around 90 g CO2-e/kWhel).

Sovacool, 2008 posted:

It calculates that while the range of emissions for nuclear energy over the lifetime of a plant, reported from qualified studies examined, is from 1.4 g of carbon dioxide equivalent per kWh (g CO2e/kWh) to 288 g CO2e/kWh, the mean value is 66 g CO2e/kWh.

GrumpyDoctor posted:

Install Windows posted:

What I find really funny is the proposal only proposes to replace fossil fuels, but the ending thing never mentions nuclear anywhere. Are they saying we can just generate 20% less power flat out?

Jacobson posted:

4. Effects on climate-relevant emissions

In this section, the CO2-equivalent (CO2e) emissions (emissions of CO2 plus those of other greenhouse gases multiplied by their global warming potentials) of each energy technology are reviewed. We also examine CO2e emissions of each technology due to planning and construction delays relative to those from the technology with the least delays ("opportunity-cost emissions"), leakage from geological formations of CO2 sequestered by coal-CCS, and the emissions from the burning of cities resulting from nuclear weapons explosions potentially resulting from nuclear energy expansion

Renaissance Robot posted:

Oh, it mentions nuclear alright. If you read through the first part, you'll notice that the author declines to post any figures relating to nuclear, instead citing another paper which concludes that nuclear is worse than other low carbon options for [reasons]. Naturally, I decided to take a look at this other paper:




For bonus fun, check out this table from page 6.

quote:

^aExtractable power over land. Assumes the surface area over land outside of Antarctica is 135000km²,