scalbers

http://news.mongabay.com/2008/0815-solar.html PG&E will build the world's largest solar power plant California electricity producer PG&E Thursday announced a plan to build two giant solar photovoltaic power plants that will cover 12.5 square miles and have a peak generating capacity of 800 megawatts. The plants would would the size of the largest photovoltaic installation presently in the United States, the 14 megawatt plant at Nellis Air Force Base in Nevada. The proposed plants — expected to be completed in 2013 — will be located in San Luis Obispo County in central California. The 800 megawatts is 3.6 times the total capacity of photovoltaic installed in the U.S. in 2007 and equivalent to about 30 percent of worldwide installations for the year. PG&E estimates the plants will deliver cumulatively 1.65 billion kilowatt-hours of renewable energy annually, or enough to power approximately 239,000 residential homes each year. "These landmark agreements signal the arrival of utility-scale PV solar power that may be cost-competitive with solar thermal and wind energy," said Jack Keenan, chief operating officer and senior vice president for PG&E. Over the past six years,PG&E has entered into contracts for more than 2,500 MW of solar power.

Yes, interesting to see this treatment of negative energy in the context of an Anti-De Sitter space. I'm wondering a bit however how this might relate to the "actual" universe, where we see an apparent accelerating expansion. Supposedly the convention is that a positive pressure (as mentioned in the AdS Wikipedia page) corresponds to an attractive force that would slow the expansion. Is there a context you are considering where a positive pressure accelerates the expansion? On the other hand - here is a connection of negative energy with the Higgs field in this other forum thread: http://www.physicsforums.com/showthread.php?t=170030

Actually the article states that 0.3% of electicity is solar in Germany. The output is 0.5% worldwide if you count other types of solar. And I'm very happy thank you with the fact that grid parity has already been achieved in certain areas (like parts of CA). Nanosolar's panels (that you have yet to acknowledge in any detail) may make this happen for some towns in Germany this year. Recall that investors are putting just as much money now into solar as they are into wind. I assume they know something about the industry trends. Grid parity will be achieved in more and more places as time goes on - and 2012 is sooner than one might think. There are no alternatives sources of energy that are growing any faster on a percentage basis. If the governments would help it would be even better - here is where an optimistic attitude could translate into investment and a quicker pace of advancement. And remember I'm looking at concentrated solar power in addition to solar panels, as well as passive solar heating and solar hot water. Add them all up and the energy supplies grow. I'm patient enough to let this boom continue over the next few years, and I also champion other things like wind, geothermal, fusion, conservation, etc.

Yes, and as this article mentions, grid parity has already been achieved in parts of California. http://www.reuters.com/article/environmentNews/idUSL1878986220071019

Nice to see your numerical evidence so I can respond. We might still have to pin down some definitions on average cost or whatever. Let me try though. And what is your opinion about solar thermal plants as that is an important component of solar as well. I think they are doing fine in the desert southwestern states and places like Spain. More than a fantasy, they are quite real. Nanosolar's panels as far as I can tell are much cheaper compared with wind than your 250% cost figure. So I think this company that is ramping up to a 500MW annual production has moved beyond your definition of "wannabe". If solar panel's overall on-grid growth continues at the present 50% growth rate in cumulative capacity (starting from .04% energy share in 2006) it will reach your 1% threshold within about 6 years. With some government tax incentives to help it could be sooner. Solar heat energy usage is now about 0.5% total global energy consumption. That's more than wind at 0.3%. Wind energy is still good to consider, though it may have issues with birds.

It seems like you're a moving target sometimes. I thought you were criticizing the lack of affordable small-scale solar systems earlier. Moving forward though can you tell us in numerical terms what your criteria for success are? Whatever that is we can then predict when the criterion will be reached or if it has already. For example, I think the current global 3.5GW of photo-voltaic power generation is pretty large scale. If you add other types of solar (solar-thermal with its huge power stations in the desert now on-grid and growing fast) it becomes more. And Nanosolar should have something like 500MW of annual solar panel production either this year or around next year. That's pretty large scale to me - and pretty much in the now, moving beyond mere "experimental". These are on-grid and low cost. Again on-grid photovoltaic energy is growing at about 70% per year. That's pretty significant I think. Solar is becoming big business already - what more could you want? And the "municipal-scale" (something like 50MW) Nanosolar plants are at a nice scale. Ultimately it may be irrelevant what the size of each plant is, the total power and how fast it is growing is what should be admired more. And yes, as I said I like all the wedges - and I'd be happy to discuss each and every one of them - we can walk and chew gum as we will need them all. As an example solar energy can be used in times of calm wind. Wind energy can be used when it's cloudy. Here's a good YouTube video on the state of solar power:

I think it would be more productive to discuss the current IPCC report instead of one from over 10 years ago. There's much better scientific evidence now to debate about. ................................................................................................... Perhaps our skeptics can comment specifically on the cost of the NanoSolar (and also Sharp) thin film solar panels. Nanosolar is stating it should (as they scale up their manufacturing plants) be comparable to coal produced electricity. ................................................................................................... Just to reiterate the solar power discussion a bit, solar panels with the thin-film technology (and maybe some amorphous silicon as well) might be best applied at the medium "municipal" scale with plants about the size of 50MW feeding into the grid. The larger scale solar plants might be a mix of the solar panels and other types, such as parabolic solar reflectors or solar towers with mirrors, a number of which either already exist or are being built. The market can help sort out which solar technologies work best in various environments and situations. Interesting about the solar energy storage at night question, that electrolysis catalyst looks promising for storage of solar electricity in the form of hydrogen. http://www.sciencedaily.com/releases/2008/07/080731143345.htm The large solar thermal plants also store power in hot salts and such. Of course, most energy is used during the day so solar could still be a big player to be phased into a "mixed-energy" strategy if the energy storage systems are slower to develop. If solar power had reasonable tax incentives (given that oil companies have them), it would probably help. A national effort at better power grids (e.g. for DC power from solar) would also be a help.

It's true that "off-grid" panels for the small home user are still expensive and may take a bit longer to come down. However the "municipal" scale is an example of what is taking off and is almost as we speak becoming competitive with coal and such. We as a society should grasp onto this emerging reality, along with the other wedges in the energy/carbon solution pie. Nanosolar and Sharp will between them have grown to about 1500MW annual manufacturing capacity (of the relatively cheap thin-film panels) by 2010 with a steep industry growth curve. If you factor in the negative costs of global warming (as I mentioned) solar becomes quite attractive. This (along with wind) is where the lion's share of renewable energy investment dollars are going. In addition to this Polysilicon prices are becoming less of a factor since thin-film solar panels are growing faster and are already overtaking traditional silicon panels in the US in market share.

And inside your last link I see this conference paper with a good summary. Table III is interesting and shows both Sharp and Nanosolar as thin film leaders over the next couple of years. This table is confusing to me though in that the first two columns (present + additional) only sometimes add up to the "total". I sent an email to one of the authors with one example (for Sharp) and received the reply that "if it is..it is a typo". http://www.nrel.gov/docs/fy07osti/42058.pdf In figure 3 of this report we see that grid connected solar PV is the fastest growing form of renewable energy: http://www.ren21.net/pdf/RE2007_Global_Status_Report.pdf

And here's another list that shows some of the relatively low cost ones. http://www.ecobusinesslinks.com/solar_panels.htm I think Nanosolar is much cheaper and may not be included as it is still in the process of scaling up and already has their stock sold out for the year. They are focused at present on municipal scale solar power arrays though hopefully will also have residential before too long. Here is their thin film "printing press". http://www.nanosolar.com/blog3/ We might also consider concentrated solar power that has some intriguing designs and is taking off on a large scale in the U.S. desert southwest and in other countries. There are several designs, some are more practical (e.g. parabolic trough), while others (solar chimney) are more fanciful so we'll see if they can materialize as in this catchy video. Solar power towers surrounded by an arrays of mirrors are kind of neat with a science fiction look to them. http://en.wikipedia.org/wiki/List_of_solar_thermal_power_stations With some investment in power distribution grids this technology could benefit even more people at some distance from the sunny source regions. On another note here's my comment on "stupid actions"... I agree with most of these two lists, though I would offer a few perspectives: Being even partially vegetarian can be a help to reduce meat (think portion sizes and mixing meat with tofu) and still get your vitamin B12, lots of iron in spinach too. How many people simply overeat and are overweight in the U.S. and elsewhere? Reducing car travel is a good idea. More walking and bike riding is healthy and taking mass transit reduces road congestion and usually helps fuel efficiency. I'm still optimistic that nuclear fusion will work at some point and should be invested in more. And the sometimes taboo suggestion, how about fewer kids on a global basis? Steve

It would be nice if we could communicate more fully as a group in this forum. Did you see my post about Nanosolar's panels being competitive with coal at about $1 per watt? http://www.nanosolar.com/ Steve

Actually, companies like Nanosolar are bringing solar down to costs competitive with coal (around $1 per watt). With a modest investment this can be scaled up to help reduce costs even more. If you furthermore count the environmental impact into your economic calculations, then solar might win hands down.

I agree we should act more quickly since the current pace is in the opposite direction of what we want (increasing emissions every year). Clearly we should step up the pace if we want to phase out fossil fuels within 30 years or so.

I guess I would have to learn more about what comprises coherent photon interference and how that differs from incoherent photons or waves. I can say that I've personally seen electron diffraction in physics class using crystals as gratings.

Greetings, A few posts back there was a comment that a past interglacial was 2C warmer so the natural interglacial should do the same this time. I think the Earth's orbit is more circular now so the amplitude of the glacial cycles will be less. Also we should actually be headed towards a cooling now considering the Earth's orbit. This is likely being overridden by human activities however - and then some. I think people can adapt to an extent to changes in climate, however if the natural ecosystems start to collapse would that really be good for humanity? I think that is a real concern. Remember the ocean acidity as well. The cost of solar by the way sounds less than what we pay in the U.S. for oil from other countries. Steve

Well since there are so many photons being emitted this might compensate for the weakening of the associated traveling waves as they spread out. Speaking of photon wave functions (a good Google search phrase), here is a nice little paper that does briefly mention vacuum polarization: http://arxiv.org/abs/quant-ph/0508202

I'm a little unsure of the various alternatives you contemplate here if you care to elaborate. A supernova probably emits energy in fairly exotic ways. If it's thermal emission from a hot gas of some type, then atomic emission seems reasonable. I think they can survive the long journey fairly intact.

And here's a more up-to-date reference again from Ned Wright that supernovae have now been measured up to z=1.75. Also a good discussion on how all the data fits together with the cosmological models. http://www.astro.ucla.edu/~wright/sne_cosmology.html

Yes that would be roughly 3 times. Here's what I get, note the various measures of the distance (light travel, angular size, luminosity) are all diverging as we are really getting cosmological. This underscores the fact that there's more than mere "distance" that determines how visible distant supernovae and galaxies are. Glad you like this abacus! For Ho = 71, OmegaM = 0.270, Omegavac = 0.730, z = 1.000 * It is now 13.666 Gyr since the Big Bang. * The age at redshift z was 5.935 Gyr. * The light travel time was 7.731 Gyr. * The comoving radial distance, which goes into Hubble's law, is 3317.2 Mpc or 10.819 Gly. * The comoving volume within redshift z is 152.895 Gpc3. * The angular size distance DA is 1658.6 Mpc or 5.4096 Gly. * This gives a scale of 8.041 kpc/". * The luminosity distance DL is 6634.3 Mpc or 21.638 Gly. 1 Gly = 1,000,000,000 light years or 9.461*1026 cm. 1 Gyr = 1,000,000,000 years. 1 Mpc = 1,000,000 parsecs = 3.08568*1024 cm, or 3,261,566 light years.

I would suggest trying out Ned Wright's cosmology calculator to see what you get: http://www.astro.ucla.edu/~wright/CosmoCalc.html

The high red-shift supernovae are perhaps most notably the key to the accelerating universe, and they've been seen to a red-shift of 1.0 or so.

The relative brightness of objects (and by implication their respective visibility at various distances) is easiest for me to express in terms of absolute magnitude. The brightest stars as mentioned before are around absolute magnitude -10 (visible around 3 billion light years away with a +30 apparent magnitude limit). The Milky Way Galaxy is -20 and the brightest galaxies are actually -22 (instead of what I said earlier). In this context a supernova might be around -15. A quasar I'm unsure of though it appears some can outshine entire galaxies. It seems like galaxies can POTENTIALLY be easily seen at distances well beyond 10 billion light years, however they APPEAR dim due to the red shift. The red shift might even play a role in the visibility of the more distant supernovae. Another issue might simply be that stars wouldn't be isolated very far away, so one in practice might only resolve the larger galaxy, even in cases where one could in theory see something the brightness of a star. So the exact situation might depend on what particular distance and object you want to talk about and whether the object is by itself or immersed (as is typical) in a galaxy.

Clarifying this a bit more, the sun would be +43 magnitude at 1 billion light years. It would be at a +30 magnitude HST visibility limit if it were located 2 million light years away.

I agree the solar activity has been fairly constant the past few decades and thus would not explain the current warming. As for sea level, an accelerated rise (well beyond the historical 1.8mm/year) would be a big deal for modern civilization with all the coastline development. Overall, perhaps the warming is most harmful in its ecological effects in shifting the ranges (or existence) of many forms of life, particularly when habitat is fragmented by human development. Ocean acidification poses threats to the entire marine food chain, if overfishing weren't enough already.

Yes, we might also note that a Jansky is flux per hertz of frequency, so this has to be integrated over the range of visible light to help get a photon count. http://en.wikipedia.org/wiki/Jansky