Climate Policy

[kandrathe]

BTW, why do people include nuclear with renewable? Clean, yes. Eco-friendly, yes. Uses a fuel with no better uses? Yes. But renewable? Not unless you have a super-nova handy.

I'm still hopeful we resolve that fusion self-sustaining reaction problem here in the next 20 years or so. Another good place for stimulus spending. :)

[--Pete]

Hi,

. . . you need doctoral degrees . . .

Never confuse knowledge with the certification of knowledge. Many who know have no certificate, and many with the certificate really do not know. I've worked with both types.

--Pete

[--Pete]

Hi,

I'm still hopeful we resolve that fusion self-sustaining reaction problem here in the next 20 years or so.

I believe I explained what "20 years" means in the scientific context. Basically, like "forty days and forty nights" in the Bible, it means a long but indefinite time. Nuclear fusion is about twenty years away and has been for the last fifty. :lol:

--Pete

[Zenda]

BTW, why do people include nuclear with renewable?

Once in a while, Pete says something I can agree with. That's good :wub:

[kandrathe]

Let me ignore most of your post as unsubstantiated argumentation. For example, how would you collect the solar energy that lands on the Pacific ocean? Placing PV cells in the Sahara sounds good, until you try to figure out how to keep them clean, and get the power to the where it is needed. As far as payback... The operative words are "can be", they also are frequently not. In my case the net savings over grid power is negative for the entire life of the panels. Show me a source for "germanium in amorphous silicon-germanium thin film solar cells", and let's compare the costs. Let me just conclude that I won't continue to engage in a battle of wits unless you prove you are armed.

No, I used that site because it steps through all the math (1 thru 7) I just outlined, although I substituted some of the US values for UK, and used the commercially available 20% for panel efficiency rather than his use of the lab available values of 30%. The math is this professors math, and not mine (although his values are similar to mine).

9041 Wh/day = 9041*60*60 Joule/day = 9041*60*60/24*60*60 Watt. If we divide that by 4, we get 9041/(24*4) = 94.2 Watt. Looking at your (wrong) number of 23 W/m2 for northern U.S. (winter), it would seem we need less then 4 m2 even there:)

For someone who claims to have a feel for math, you are pretty bad at it. Do you really believe you could run a home on a 94 Watt system? What is the Watt rating on your refrigerator?

It is not a mathematical derivation, just a "rule of thumb". Which is why I said, "The usual formula for figuring peak watts needed is to take Watt Hour per Day divided by 4." If you take WH per day / 4 you get an approximation for system peak watts.

Taken from this site. Which is pro-solar. Let's validate my calculations using someone else's calculator. Plug in, 55412, XCEL, 3300 kWh/month and 100% generation. Voila! Minimum system size: 3000 Watts. That is actually more than my calculation of 2260 Watts. And, they estimate (wrongly actually since only in the height of summer would I get anywhere near 4.77 kWh/m^2 per day, or 600 W/m2 peak sun which is double the value from Texas) I will need a roof area of 254 sq-ft or about 24 square meters. Which is most of it.

[kandrathe]

Never confuse knowledge with the certification of knowledge. Many who know have no certificate, and many with the certificate really do not know. I've worked with both types.

That reminds me of my undergraduate physics class. For the bi-weekly test, the prof would have each of us submit 2 possible questions for the test. He would select 10 questions for the test. If yours was selected, then of course you would "know" one of the questions.

Mine were never selected, but he frequently commented that they would be the basis of a good doctoral thesis. I remember one I submitted asked the question about a theoretical toroidal space station which was rotating sufficient to maintain earth gravity. The question was what would happen to the center of momentum, and the orbit of the station if there was an emergency which forced all the passengers to one location of the station.

[eppie]

It is quite an undertaking to convert from one system type to another. Rather than credits, I think it would be helpful to provide low interest loans (maybe a special class of 2nd mortgage) attached to the home. For northern climates, I think ground installed geothermal heat pumps make the most sense for domestic heating, with electricity generation being done by the best renewable method for that area (nuclear, wind, geothermal steam, solar, tidal, etc.).

Have you heard about WhisperGen?

It would seem a crazy thing to do 2 years ago. But if you see now what has been spend on bail-out money, your idea actually seems pretty good.

[eppie]

Measurable ocean Ph is rising,

Do you have a link for this. I was under the impression that oceans were getting more acidic.

[eppie]

Let me ignore most of your post as unsubstantiated argumentation. For example, how would you collect the solar energy that lands on the Pacific ocean? Placing PV cells in the Sahara sounds good, until you try to figure out how to keep them clean, and get the power to the where it is needed. As far as payback... The operative words are "can be", they also are frequently not. In my case the net savings over grid power is negative for the entire life of the panels. Show me a source for "germanium in amorphous silicon-germanium thin film solar cells", and let's compare the costs. Let me just conclude that I won't continue to engage in a battle of wits unless you prove you are armed.

Kandrathe, on one hand you regard nuclear fusion as an alternative while you see all the problems when talking about solar energy.

1. Photovoltaic cells are a proven technology, and apart from the most expensive one (crystallin silicon) that you always mention there are many more kinds, while nuclear fusion is a technique that might turn out to be impossible to use practically for energy generation (and I am among the most positive persons when thinking about what scientific progress we will make in the future).

2. the aformentioned other kinds of photovoltaic cells have one thing in common; they are much cheaper than crystallin silicon cells. There is a huge body of research going on to organic, dye sensitzied, quantum dot etc. solar cells, and if we would compare this with eg the first cell phones where the initial sales by tech-freaks fund the further research in making better ones (like we have today) exponentially, early adoption of these might really boost this field even farther.
Most other solar cells don't have the high yield (50 % of the yield of a silicon one would be great), but are factors cheaper. There are plants making several types of them now, and within a few years this will really catch on.

3. We don't have to generate 100% of our energy using solar. But even in a country like holland, solar cells on roofs of houses, maybe combined with a solar boiler, will dramataically decrease the amount of power you would need to get from your local powerplant. (remember that solar cells that are on your roof will ensure much less loss of current because of transport....something that (I think) is usually not considered when talking about power efficiency from conventional power plants.

4 the needed area; photovoltaics will likely be most used on the place were the power is needed. So on roof and in windows (transparent cells that use UV and/or IR for the energy conversion). There are many place where we can use solar panels.




I am always amazed by the solar challenge in australia where teams have to drive around 5000km with a solar powered car. Of course it is in australia, and of course they use the best silicon cells for this, but these guys drive an average of almost 100km/h just by using solar cells.!!

[eppie]

That reminds me of my undergraduate physics class. For the bi-weekly test, the prof would have each of us submit 2 possible questions for the test. He would select 10 questions for the test. If yours was selected, then of course you would "know" one of the questions.

Mine were never selected, but he frequently commented that they would be the basis of a good doctoral thesis. I remember one I submitted asked the question about a theoretical toroidal space station which was rotating sufficient to maintain earth gravity. The question was what would happen to the center of momentum, and the orbit of the station if there was an emergency which forced all the passengers to one location of the station.

Although being a mere chemist and no physicist, this seems to be a first year university physics class question to me. Not one that I am able to answer:)but using classical mechanics formula. A doctoral thesis is however not the same as answering several difficult exam questions.

[Zenda]

It is not a mathematical derivation, just a "rule of thumb". Which is why I said, "The usual formula for figuring peak watts needed is to take Watt Hour per Day divided by 4." If you take WH per day / 4 you get an approximation for system peak watts.

Sure, but why do you want to compare peak consumption with total daily production? You could compare peak consumption with maximal output, but that propably doesn't make much sense unless we know that peak production is during the same period as peak consumption. You took the effort to calculate daily production, so we should compare with daily consumption. No dividing by 4 is needed here, and we would arrive at 377 Watts or 377/23 = 16.4 m2. This almost looks plausible B)

Taken from this site. Which is pro-solar.

Apparantly, being pro-solar doesn't keep them from making blunders. They say it's colder up north because the distance to the sun would be greater. Luckily, they rely on others for the actual data and calculations :mellow:

Still, 24m2 to make up for 20 kWh/day electricity consumption is not enough.

You could have saved yourself all these calculations, by looking at the link given by Jester. In the UK, where sunshine is comparable or less as in the most sunless states of the US, daily output would be 5 kWh for every 10 m2. So, to cover for your 20 kWh per day, we'd need 40 m2.

Ofcourse, like you said earlier, a hybrid solution would be best. If we'd want to offset half of your electricity consumption, we'd need 20 m2, which seems to fit nicely on your roof.

[--Pete]

Hi,

We don't have to generate 100% of our energy using solar.

Thank you for reminding us of that. All too often these discussions turn into "What *is* the solution?" when the right question is "What *are* the solutions?"

--Pete

[--Pete]

Hi,

Although being a mere chemist and no physicist, this seems to be a first year university physics class question to me. Not one that I am able to answer:)but using classical mechanics formula.

Not quite, since to do it right involves a bit of more advanced math and physics, though still classical. Don't make the mistake that 'classical' means 'simple' (although I did have a quantum prof who claimed 'classical' meant 'wrong':)).

A doctoral thesis is however not the same as answering several difficult exam questions.

Indeed. The main difference being that the answer to exam questions is known and thus boring. The results of a dissertation were not previously known, and thus interesting (at least to someone).

--Pete

[weakwarrior]

BTW, why do people include nuclear with renewable? Clean, yes. Eco-friendly, yes. Uses a fuel with no better uses? Yes. But renewable? Not unless you have a super-nova handy.

No energy is renewable - that´s a law of thermodynamics. ´Uses a fuel with no better uses and which there is plenty of´ is probably what people mean by renewable.

The main difference being that the answer to exam questions is known and thus boring. The results of a dissertation were not previously known, and thus interesting (at least to someone).

Just a nit but I´ve read plenty of Ph.D. theses (my own included) which were boring to everyone.

[eppie]

Don't make the mistake that 'classical' means 'simple'
--Pete

That's why I said classical.:D

[Zenda]

No energy is renewable - that´s a law of thermodynamics.

But doesn't the Law of Conservation of Energy state that the total amount of energy in an isolated system remains constant? Doesn't that make all energy 'renewable', if we only knew how to do it?;)

[weakwarrior]

But doesn't the Law of Conservation of Energy state that the total amount of energy in an isolated system remains constant? Doesn't that make all energy 'renewable', if we only knew how to do it?;)

That's where the 2nd law of thermodynamics comes in.

[Zenda]

That's where the 2nd law of thermodynamics comes in.

Ah, the ultimate problem. The ever increasing Entropy. Maybe we can try creating a wormhole to a pre-BigBang universe, and construct something like a Entropy Pump? Then again, according to The Gods Themselves, even that would have it's disadvantages :unsure:

[Zenda]

No energy is renewable - that´s a law of thermodynamics. ´Uses a fuel with no better uses and which there is plenty of´ is probably what people mean by renewable.

Notwithstanding my poor attempt at a humorous reply, you are correct. It would be beter to speak about 'sustainable' energy sources, I think. Wind energy would fail that criterium, if we would rely for 100% on it. Even though the total amount is 5 times the amount we need, at some point winds might not be able to deliver moisture where it's supposed to be. The same goes for (affordable) geothermal energy. It's only sustainable as long as you don't ask too much from it, or things will start to cool down.

[kandrathe]

Notwithstanding my poor attempt at a humorous reply, you are correct. It would be beter to speak about 'sustainable' energy sources, I think. Wind energy would fail that criterium, if we would rely for 100% on it. Even though the total amount is 5 times the amount we need, at some point winds might not be able to deliver moisture where it's supposed to be. The same goes for (affordable) geothermal energy. It's only sustainable as long as you don't ask too much from it, or things will start to cool down.

Let me see...

1. The sun is responsible for solar (of coarse), wind, biomass and fossil fuels (ancient plants). Wind and hydro are ways to capture solar power that evaporates water changing the density of the air (affected by gravity). Shallow geothermal (not the hot springs) is due to solar radiative heating of the ground.<>
   
2. The moon (and to a lesser extent the sun) is responsible for tidal energy, which is pretty predictable.<>
   
3. Deep geothermal is virtually limitless because it is generated by the gravitational action of the sun and moon on the earth as well as radioactive decay.<>
   
4. Other chemical reactions releasing energy <>
   
5. And, then, there is nuclear power, both fission and fusion.<>
   [st]And, who knows, maybe there is something else we haven't discovered yet.
   
   I'm researching the power possibilities of sterling engines with solar in cold climates. Energy output should be commensurate with the differential between the heated cylinder, and to cooled cylinder. It should produce more energy the colder it is outside, and then in summer with longer warmer days, the differential is less of a concern due to the longer generation time. It is hard to say without doing all the math though, the additional summer solar flux may increase the temperature differential to much higher level. (Air temps here go as low as 245K, and as high as 316K, but solar focused through a lens might go as high as 2000K).
   
   Even for automobiles, this engine design is much better than my crazy wind up spring musings. The energy source can be anything hotter than air, and once moving it would be easy to use a scoop and evaporation to super chill the cool side. I envision the engine would be like the Th!nk Nordic City used to recharge batteries, which would drive an electric motor for propulsion.
   
   Stirling Engine Hobbyist Homepage
   
   Stirling Engine Efficiency
   
   Stirling Engine Design Program