Solar Thermal. This isn't Your Grandma's Solar Energy! II

This is very accurate in deplicting that there is no net change in gross energy being provided by the sun.

Also of note is that the "Rated Capacity" also referred to as the "Peak Capacity" of a solar thermal system only occurs on one day for about one hour on rare years on the Summer Solstice when, based upon the Earth's orbit, it coincides with the Earth being closest to the sun. On that day for that one hour the sunlight travels through the least amount of atmosphere and with the Earth at it's closest point to the sun there is the most energy from the sun. For that one hour the solar thermal collector will collect the maximum amount of solar energy possible. The rest of the time the system is collecting less than the maximum amount of energy possible.

 

http://www.politicalforum.com/curre...mes-solar-hot-water-equipped.html#post4960723

The Israelis have figured that out too.. and its now mandatory in Hawaii.

 

That's why I used an annual average in my calculations, which gives numbers that are more easily interpreted correctly.

Shiva, your statement is true, but somewhat misleading. The elliptical orbit of the earth only causes a variation of less than 7% in solar irradiation throughout the year. The rare ideal hour when the sun is closest during summer is pretty irrelevant for all practical purposes. I prefer to let an expert in the field rant about rare, but insignificant astronomical events.

[ame="http://www.youtube.com/watch?v=TfF05kPNKNw"]Neil deGrasse Tyson on Being Close to Mars - YouTube[/ame]

 

Yes, I as you seem to indicate I like balance. I own a modest amount of forest land. If I had my druthers I would never sell an inch of property for timber. Still I have sold some timber for pizzas and coke, being hungry ain't fun! Ha ha~. To add to the temptation, the price of timber and even pulp wood is gone up substantially. (wood seems to be linked to gold, and in a way that makes sense). The price for standing timber is where one can expect to make roughly 4k an acre selective cutting.

Anyway; yes I agree with you we need the EPA but we should strive for balance, preferably the large part of the balance should go towards nature and the small end to profits. I highly disargee with forest land that allows absolutely no human activity.

Rev A

 

That coincidence actually happens about once every 23,000 years. So don't hold your breath.

 

Sorry, but there isn't any information related to the ecological damage this solar power plant might be causing to the desert. The Sahara is one of the most fragile of all desert ecosystems and to believe that a power plant of this size will cause no harm is purely speculative and completely unsupported by any facts.

 

Solar water heating has been shown to be cost effective and can produce a huge amount of solar power for a nation reducing other energy requlrements.

The three cost effective uses of solar energy are:

Passive solar where the structure design incorporates considerations for solar space heating (and cooling) reducing energy needs.

Active solar space heating/cooling. This uses flat panel solar thermal panels that both heat the home and remove heat from the structure to cool the home. This uses unglazed solar thermal panels installed on the structure's roof.

Active solar water heating. This uses glazed flat panel solar thermal panels installed on the structure.

These are proven, cost effective, uses of solar energy. This is not true of large scale solar electrical power production where the costs significantly exceed the cost of other sources of electrical power production.

 

Yes, indeed. The more the better.

Ludwik Kowalski (see Wikipedia)
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Keep in mind that the coal fired plant has significant costs besides the cost of coal. The coal plant needs maintenance and repair/replacement just like the solar plant, and these costs tend to be significant compared to the cost of fuel.

 

I am a physicist and engineer, but I knew very little about the specifics of thorium reactors before I read your post so I decided to do some research. What I found is that presently the cost of thorium is about $5,000 per KG. Some people in the industry claim that the price could come down significantly if more thorium was mined and refined, but that is conjecture not fact. Presently the salt refining necessary for a thorium reactor is considered to be cost prohibitive, but again, there are people who claim the costs of such refining/reprocessing would come down hugely if the process were commercialized. However, the present consensus is that the entire salt purification process is not commercially viable. Though it is entirely possible that thorium reactors could be made to produce cheap, safe power with little concern for diversion to weapons, and little waste disposal issues, presently none of this has been proven to be the case.

 

The solar power plant on Farasan Island is operational............

 

I keep that in mind. There are many costs other than fuel. Coal, for example, also needs "scrubbers" to reduce air pollution. It's not easy to take all relevant costs into account for a good estimate. My approach is to look at significant differences in the various sources of thermal energy only. At similar temperature and power, thermal power plants could use the same steam turbines and generators for different energy sources. Nevertheless, I need a lot more information for a meaningful comparison. Maybe I find some time to gather some numbers. I'm curious, but I guess that this kind of information isn't easy to come by.

 

Thorium is a waste product in the refining of rare-earth minerals. Rare earths like neodymium are currently in high demand for use as lightweight magnets, like those used in wind turbines. Do you know why rare earths aren't mined in the US today? It's not because we don't have any; we have lots. We don't mine rare earths in the US because nobody knows what to do with the thorium left over. The NRC calls it "nuclear waste". This is fact, not conjecture.

If you can find something useful to do with large amounts of thorium, people who mine rare earths will pay you to take it off their hands.

If thorium really costs $5000/kg, how can refining it be cost prohibitive? Something smells very fishy. How about quoting a source?

False. We built a LFTR in the 1960s. We know it works.

 

Operation and maitanance (O&M) costs are, of course, a consideration in the total costs for the consumer and those costs were addressed by the DOE in the study previously provided. As with the capital investment costs this relates to the "Rated Capacity" (i.e. peak potential capacity) and must be revised based upon the "Capacity Factor" which reflects net power is actually going to be provided to the customer on a 24/7 basis. For coal with a capacity factor of 85% there is a slight adjustment to be made while for solar thermal with a capacity factor of 18% the adjustment in the O&M costs is significant.

 

Thorium dioxide costs only a few tens of dollars per kg. I dont know the cost of pure thorium, tough.

One tonne of thorium burned in a LFTR will produce around 1 billion $ worth of electricity.

 

Pure thorium isn't used in a LFTR, you use thorium fluoride (ThF4) instead. This is created very easily by flourinating thorium dioxide. The fluorine wants the thorium more than the oxygen does.

Which shows how ridiculous the cost-of-fuel issue is with LFTR. Or indeed, with any nuclear power.

 

Nobody suggests that thorium reactors don't work, what is true is that presently they are not cost effective and nobody has a tested design that appears to be cost effective.

 

What is the source of your claim that they are not cost effective? Did you just make this up off the top of your head?

 

Id like to see a source, too, I doubt that is true. According to my research, they would be very cost effective, maybe even beating fossil fuels.

 

Conventional LWRs already beat fossil fuels. LFTRs would be even cheaper: since they can't melt down, you don't have to build in primary, secondary, and tertiary emergency cooling systems. Since they run at ambient pressure, you can't have a steam explosion, so no huge containment building. And with that, a large fraction of your construction costs vanish.

 

Great debate everyone. I am in Shiva's and Poor Debater's etc corner for various reasons. That said I would rather employ solar and other non toxic energy sources rather than fossil fuel and fission reactors for our primary means of producing energy, but remain convinced they lack the brute force to accomplish the energy required at a cost competitive basis.

I am sure that a slightly modernized form of LWR's all with a standard design along with a relaxing of EPA* and other watch dog and regulatory groups stranglehold on the nuclear power industry would trump all other methods of energy production alternatives.

*(such as allowing on site storage in vaults that would store the waste for a maximum of 500 years).

**(hopefully a secondary form of energy production using waste heat of the decaying radioactive waste to vaporize a working gas for use in a turbine etc).

Even if the new fission reactors could be brought on line, still LWR's would hopefully be a short term solution, if I had the administrative and executive power, I would use the time that the fission gap provided to plow money into fusion all forms of solar space based generation etc.

Rev A

 

So, what is holding us back from really going ahead with Thorium (remembering that since it is a by product of the refinement of rare earths there is plenty around)

 

There is a company (Flibe Energy) that's going ahead with design right now. And the Chinese are apparently building a LFTR right now.

The primary issue holding us back in the uncertain regulatory environment. Most of the NRC rules are based on avoiding or mitigating LOCA (Loss Of Coolant Accident), which is impossible to occur with a LFTR. So we first need to convince NRC (and perhaps congress) that these rules don't make sense for LFTR. Then, of course, they'll want to write new rules.

 

When it comes to nuclear we Aussies hang out from the rafters by our toes and watch - we have ONE ageing reactor that makes medical supplies and that is IT. Soon as we no longer need it for even that we will cheerfully decommission it and join NZ in being a nuclear free zone

But Thorium does look attractive, less waste and what we have does not last thousands of years.

Personally I think we will end with a mixed bag of innovations for energy production with storage capacity built into the newer models - and THAT is an idea long overdue

 

If thorium reactors are cost effective and safe then private enterprise will fund their construction. I see no problem with this and perhaps private enterprise will capitalize their construction in the future. Based upon what I know I might even invest in an IPO for a thorim powerplant but I would need to read the actual prospectus for the corporation.

My case would be against government funding or subsidies for any power plant construction. If it's cost effective it doesn't require government funding or subsidies.