- #351
mheslep
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er AGW. Chu spend some time in his road show briefing on global warming.signerror said:...
AWG?
er AGW. Chu spend some time in his road show briefing on global warming.signerror said:...
AWG?
signerror said:Well that was Obama's decision, not Chu's. He'd already decided early on in the campaign - his reasoning is here @3:11:
There lies my complaint. Obama has made a great deal of noise that only the science would rule the day in his administration. So far, based on comments like the above and Chu's http://neinuclearnotes.blogspot.com/2009/03/john-mccain-and-steven-chu-on-yucca.html" , it is fair to say that the only-the-science claims are stuff and nonsense.Obama said:I didn't rule out a central location, what I ruled out was Yucca Mountain, because it turns it is built on a fault line. And the way that this was shoved down the throats of Nevada ended up souring the politics in such a way where it's almost impossible to get it done now.
http://video.aol.com/video-detail/top-gear-reviews-the-tesla-roadster/405236758812.5 thousand RPM, I can not believe this! That's biblically quick!
I guess at this point it is tough to separate the two, as Chu is now necessarily a mouthpiece for Obama. Is that better or worse than if this was Chu's true view?signerror said:Well that was Obama's decision, not Chu's.
Perhaps the fault is a legitimate reason, perhaps it isn't - as far as I know, there have been no official reports on the subject, so it doesn't seem responsible to make what looks like a snap decision.He'd already decided early on in the campaign - his reasoning is here @3:11:I didn't rule out a central location, what I ruled out was Yucca Mountain, because it turns it is built on a fault line. And the way that this was shoved down the throats of Nevada ended up souring the politics in such a way where it's almost impossible to get it done now.
LONDON(AFP) (AFP) – US Energy Secretary Steven Chu said Tuesday the Obama administration wanted to paint roofs an energy-reflecting white, as he took part in a climate change symposium in London.
The Nobel laureate in physics called for a "new revolution" in energy generation to cut greenhouse gas emissions.
But he warned there was no silver bullet for tackling climate change, and said a range of measures should be introduced, including painting flat roofs white.
Making roads and roofs a paler colour could have the equivalent effect of taking every car in the world off the road for 11 years, Chu said.
It was a geo-engineering scheme that was "completely benign" and would keep buildings cooler and reduce energy use from air conditioning, as well as reflecting sunlight back away from the Earth.
For people who found white hard on the eye, scientists had also developed "cool colours" which looked to the human eye like normal ones, but reflect heat like pale colours even if they are darker shades.
And painting cars in cool or light colours could deliver considerable savings on energy use for air conditioning units, he said.
. . . .
Doesn't sound like this in intended to have anything much to do with energy efficiency, except in that car reference. It must be about increasing surface albedo to counter AGW. I doubt you count on absorbing much heat through your home's roof on those cold winter days.Astronuc said:US wants to paint the world white to save energy
http://news.yahoo.com/s/afp/20090526/sc_afp/climatewarmingusbritainchu
Except for the light scattered at angles. And why not direct the light into buildings and use visible sunlight to illuminate interiors rather than electric lights?
Also, on a cold winter's day, I like having a house that absorbs sunlight. So maybe we can cover all buildings with giant venetian blinds that are white on one side and dark/black on the other.
Might be, but you'd have to calculate the cost-benefit ratio. Having it white would be a lot cheaper.Astronuc said:I think the back side (north) of my house roof would reflect light into the backyard. On the front side (S), rather than white, I would think a solar panel or solar water heater might be better.
Well Obama said white, but the silver is really the more common - same idea.My office overlooks the roof top of a two story building. If that was white (reflective), I'd probably get glare through the window. As it is, the roof was painted with a silvery grey coating, and that may already reflect some light. I'll have to look the next sunny day.
AKA "air conditioning"... A "heat pump" is what it does in the heating mode. In air condiitoning mode, it is just a normal air conditioner (though perhaps it uses water for heat rejection...?).My office building uses heat pumps to transfer heat out of the building...
AKA, "economizer mode". It is now essentially required that HVAC systems take advantage of it being cold outside to use that cold instead of mechanical cooling. But you'd still save on mechanical cooling in the summer and fan energy in the rest of the year if the roof were reflective....and during fall, winter and spring we open the windows to let cool air in, and minimize the use of A/C.
Welcome to PF HempForPres.HempForPres said:I have to disagree with you on the topic of nuclear energy. In the process of finding, digging up, refining, delivering and then disposing of the waste, we use so much carbon-based fuels (oil, coal, natural gas) that it takes fully 20 years of running to make up for it before you produce a single watt of "clean" power. Furthermore, there is only a finite amount of uranium in the earth, which means we'll hit "peak uranium" very fast...
Go green!
http://www.bluechipearth.com - A Green Industry Future Forum. Come join the conversation!
mheslep said:... Tesla and other EVs use about http://en.wikipedia.org/wiki/File:Graph_Evolution_of_Tesla_Roadster_Efficiency.PNG" at about $600/kWh of Li-Ion battery capacity that should last 100k miles. Better Place's exchange stations must maintain some battery stock, assume 30% stock beyond the batteries on the road. The battery cost per vehicle is then: 161km x 17kwh/100km x 1.3 x $600/kWh-LiIon = $21.2k/vehicle or $0.21/mile. The electric energy cost at $0.09/kWh is $0.025/mile. Total battery and energy cost: $0.23 / mile. ...
HempForPres said:I have to disagree with you on the topic of nuclear energy.
[ ... ]
So think twice before you give the thumbs up to nuclear. It's not worth the price, it's not worth the pollution, it's not worth the risk.
Go green!
http://www.bluechipearth.com - A Green Industry Future Forum. Come join the conversation!
Long? You have a great deal of patience vanesch.vanesch said:You know, I've been in a long discussion in my country with people who think like you. ...
drewk79 said:Eventually we will have to use renewable resources to power the planet. All others (nuclear, fossil fuels etc.) will run out.
Tons and tons of common sense in this post.vanesch said:A friend of mine once had a stupid car accident. I was in the car (nothing serious, but the car was damaged) It happened as follows: there was a very long, straight road with many successive crossings, and at each crossing, there were traffic lights. He was fixing the traffic light "at the horizon", some 6 or 7 crossings further, and it was green. But at the nearest crossing, the light was red and he didn't see it, because he stared at the remote traffic light, and BONK.
The Romans didn't have to solve our energy problems. People from the 18th century didn't make plans (or relevant plans) for our current energy provision.
Let's solve things for the next few decades, let's maybe try to think 50 years ahead. And beyond that, anybody's guess is good enough, I'd say. It is not because nuclear might meet a fuel problem in 5000 years or so, that we can't use it to solve a problem in the coming 50 years, no ? 200 years from now, society will be different, technology will be different, the problems will be different, and our thinking about that now is going to be utterly irrelevant.
No he does not say this.drewk79 said:I recently read a great book by David Mackay. Energy without the hot air.http://www.withouthotair.com/
He says if we wanted to stop using fossil fuels we would need to build 5 times the current level of nuclear plants plus cover California in windmills plus each person would have to install 80 sq meters of photovoltaic cells plus cut our energy consumption in half.
drewk79 said:I think it is important though to know in the end we will have to be 100% renewable. So hopefully we can take the shortest path between there and here.
drewk79 said:I am also working on a system and I will be coming out with it in the next few days.
I don't see how such thought experiments are useful. The only part of it that comes anywhere close to realism is the 5-fold increase in nuclear power. Everything else is just daydreaming:drewk79 said:Here is a portion of David Mackay's article from CNN...
I hope these numbers convey the scale of action required to put in place a sustainable energy solution.
None of those have any potential:What about tidal power? What about wave power? What about geothermal energy, biofuels or hydroelectricity? In a short article, I can't discuss all the technology options.
There is no realistic generation potential there. Heck, the energy usage of the average home isn't even that big a factor in the thought experiment. It is only something like 1/10th of our energy use. Most people use as much energy driving to and from work every day than their house uses during the day! (a gallon of gas is 45 kWh)I feel we need to as a country begin to develop small scale ways for each home to harness energy.
If my poop smelled like cinnamon apple crisp, I could sell it as an air freshener! This just isn't reality.There are 125 million homes in America. Each home spends hundreds of dollars on energy a month. If there was a cost effective way for us to make our own energy we will be on the way to becoming energy independent.
drewk79 said:As a thought-experiment, let's imagine that technology switches and lifestyle changes manage to halve American energy consumption to 125 kWh per day per person.
That's more like it - no summing them altogether with the "plus"s used above.drewk79 said:Here is a portion of David Mackay's article from CNN
http://www.cnn.com/2009/TECH/science/05/13/mackay.energy/
As a thought-experiment, let's imagine that technology switches and lifestyle changes manage to halve American energy consumption to 125 kWh per day per person. How big would the solar, wind and nuclear facilities need to be to supply this halved consumption? For simplicity, let's imagine getting one-third of the energy supply from each.
To supply 42 kWh per day per person from solar power requires roughly 80 square meters per person of solar panels.
To deliver 42 kWh per day per person from wind for everyone in the United States would require wind farms with a total area roughly equal to the area of California, a 200-fold increase in United States wind power.
To get 42 kWh per day per person from nuclear power would require 525 one-gigawatt nuclear power stations, a roughly five-fold increase over today's levels...
Sure, so would money rain. But that doesn't make it realistic. Thermodynamics puts pretty hard limits on what efficiency gains can be had. There are some gains to be had with improved insulation, but modern homes are already pretty good. And they aren't the big energy users anyway: business are and they also have hard constraints on energy consumption (ventilation and equipment loads).Astronuc said:Cutting energy consumption in half would seem to be a good thing.
Astronuc said:This might be of interest to some
Handbook of photovoltaic science and engineering By Antonio Luque, Steven Hegedus
https://www.amazon.com/gp/product/0471491969/?tag=pfamazon01-20
Cutting energy consumption in half would seem to be a good thing. We could eliminate a lot of garbage by not producing so much junk in the first place.
A good part of the difference in per person energy usage between US and the UK must be attributed to the population distribution over a large country and consequent transportation needs, and not so much to lifestyle differences. For further evidence see Canada, which covers a vast land area and has a higher per person energy usage than the US but with a slightly lower standard of living.vanesch said:...The "250 KWhr/day per person" in the US is divided by 2, simply because his argument is based upon the UK, and there, energy consumption is about half of it, 125 KWhr/day per person, and he has all his numbers ready for this quantity.
Now, living standards are higher in the US than in Europe, but one is nevertheless left with the sentiment that there must be more potential for simple economies of energy in the US without affecting lifestyle, as energy-saving measures which are already in place since long in Europe are not so much applied in the US as far as I understand. Now, as living standards in the US are higher, it will probably not be possible to bring US consumption down to Europe's consumption (halving), but some diminishing must surely be feasible...
gmax137 said:More important, mgb_phys is quite correct in pointing out the difference between average usage, and usage in the average home. Check into the amount used in office space, retail, and industrial facilities.