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

Originally Posted by bugalugs

Do you want to give a reference for that? It looks like bollocks.

EIA subsidy report 2007.

Originally Posted by bugalugs

Especially since the IEA recently said:

Renewable energy becoming cost competitive, IEA says
The IEA's report disagreed with claims that renewable energy technologies are only viable through costly subsidies and not able to produce energy reliably to meet demand.

"A portfolio of renewable energy (RE) technologies is becoming cost-competitive in an increasingly broad range of circumstances, in some cases providing investment opportunities without the need for specific economic support," the IEA said, and added that "cost reductions in critical technologies, such as wind and solar, are set to continue."

There's an easy way to test that: end the subsidies and see what happens.

Xcel, which has the most wind power generation of any U.S. utility, also said it may stop investing in wind farms after 2012 if a federal tax credit expires and makes new wind projects uneconomical.
http://www.startribune.com/business/134825258.html

Originally Posted by bugalugs

Yes - and pretty much everything in the coal and nuclear structure is mined too. So they are even (well not really - you need a shipload more concrete for nuclear...but I digress)

Now lets talk about the mining, processing and disposal costs of the fuels used for coal or nuclear.

1 kg of refined thorium costs $25. That enough to supply the average American home with electricity for 500 years. In other words, 5 cents a year. You lose more money in the cushions of your couch. The only other fuel processing is to fluorinate the thorium, which is ultra-cheap, perhaps a few cents per kg.

Spent fuel disposal costs of a thorium reactor: zero. LFTR's have no spent fuel and produce no long-term waste. And they can't melt down.

For both solar and nuclear (and especially LFTR), fuel costs are a negligible part of the total levelized cost of electricity (LCOE). For both technologies, it's the capital cost that's the determining factor. And capital costs for solar thermal are a lot higher than for even conventional nuclear, and the disparity will be even greater with LFTR.

Sorry Poor Debator, we were given the old "nuclear will be cheap" singsong back in the 1960s and 70s. The truth has panned out to be that nuclear waste alone is so expensive and tricky to manage and keep away from terrorists and countries like Iran that it is a policy of madness. Only the insane would consider promoting nuclear after Japan's 3 full meltdowns at Fukushima. You can't put a price tag on the fiscal damage like this, among other problems the world will surely experience as a result of "nuclear is the way to go!"...

TEPCO: New Holes In Fukushima Nuclear Reactor 1 and 3 Discovered, Radiation Leaking Into Ocean
In wake of the news that Japan has confirmed a nuclear meltdown at Fukushima nuclear reactor #1, TEPCO is now reporting the discovery of holes in the containment vessels at reactor 1 and reactor 3, which contains the plutonium mox fuel, both of which are leaking radiation into the ocean. The holes have reportedly been caused by molten lava from the nuclear meltdown at the power plant burning through the reactor walls Read more… http://theintelhub.com/2011/05/17/ja...hima-reactors/

Taken from the mother-thread: http://www.politicalforum.com/scienc...ar-energy.html

Taxing pollution, pure and simple, and pass the cost on to the consumer. The object is to stop the pollution, the consumer is the best to do this ... consume less ... common sense

DominorVobis, yes, taxing carbon emissions is great. Here's a beautiful way to reduce carbon emissions. Combine solar thermal into the existing grid connected to carbon power plants. Run the solar thermal during peak use while the carbon plants idle. Kick the carbon plant up to full tilt while there's no sun or, when the molten salt heat runs out to run generators.

In sunny areas you're going to be producing nearly 100% free energy. In more overcast and northern climes you will be reducing the carbon footprint drastically. The savings to our country would be gigantic. We could focus on producing cheap goods [thanks to cheap energy..China has figured this out and is going solar thermal like gangbusters] to trade on the world market.

Literally, China has figured out that solar thermal will put her at the top of the world financially. The US is still trying to sell collosally-expensive nuclear and pure natural gas or coal-fired steam turbines. The US has some of the most arid and sunny areas [premium for solar thermal steam] of any developed nation. So naturally, BigDirty is convincing her lackluster politician$ that their monopolies are somehow going to carry us through the 21st century as major players. If we stick with that plan, we can bank on being poorer than Bangladesh by the 22nd century.

Maybe as an adjuct to this thread, or a new focus on the topic of solar thermal could be the different types and how some are made to fail while others are not and the politics surrounding the two?..

I just find it interesting that green energy is engineered to fail. If I was BigOil, or BigNuke, hellbent on keeping the same competition I had locked away in a fiscal dungeon forever and someone was peeking in at her, I'd dress her up as ugly and anemic as I possibly could. I'd use my own money, gobs of it too, to make sure this impression came across loud and clear.

For example, since Dispondent asked for one, we have solar thermal energy. Chevron has teamed up with Brightsource to build a monument to redundancy and inefficiency "to see of solar thermal will be viable", in oil-pumping operations in California. They are using a circular array of flat mirrors aimed at a huge singular tank mounted way the hell above the reflecting mirrors. And get this: a good portion of the mirrors are facing north! They will never reflect the sun in the Nothern Hemisphere!

Why? Because of simple calculations. BigOil wants people to believe that "this many mirrors [you can include more if some of them are facing north] only produce this little amount of MW".

There are several flaws worked into this project.

1. Flat mirrors instead of parabolic concentrating reflectors or fresnel lenses. Go out in a sunny location and shine a mirror on the leg of your trousers a couple of inches away. Not much happening right? Just annoying if the glint happens to catch your eye. Now, take a magnifying lens the same size as the mirror and hold it the same distance from your pants. Have a fire-extinguisher nearby...

2. Mirrors facing north in the circular array do not reflect sunlight and are useless and must be discarded from any calculations to prove efficiency.

3. The tank, large, and located at a great distance from the mirrors has a huge interior volume of water relative to its surface area where heat-transfer happens. This means it will heat more slowly and inefficiently. With the elongate-tube style solar thermal, located much more closely to concentrating or parabolic reflectors, temperatures of over 300c [superheated steam the same caliber as with nuclear or carbon plants] is reached very quickly; as you would imagine if a whole array of magnifying glasses were aimed at your trouser leg. Less interior volume relative to surface area makes this possible. Along with of course closeness in relation to the source of heat.

Now that you know all these things, take a look at this engineering joke and laugh...

Then cry when you realize these are the lengths BigDirty power will go to in their PR campaign to destroy the competition. After all, who can compete with free superheated steam? When two plants are side by side and one of them is solar thermal and the other "conventional", one of them uses no fuel and the other one does to produce the same amount of MW. That's MW calculated from a properly-engineered solar thermal plant, and not a mock-up joke.. It's not such a further stretch then of the imagination that BigDirty would start up fake green energy plants to take Obama's funding, and then go belly up in pre-calculated fashion, make a big stink about it in the news, and use that to whip up public ire at green energy in general.

Their bag of tricks is very deep. So I say again. It's like high stakes poker. If BigDirty wants to really get into the green energy failures, perhaps a really deep investigation should go on about them and not just a surface investigation.

Or should I say, "If BigDirty wants to really get into the green energy failures, perhaps a really parabolic or focusing investigation should go on about them and not just a surficial or flat investigation...

..lol..

Someone is challenging that flat-mirrored reflection is better than parabolic or fresnel focusers.

Let's revisit the simple backyard experiment to illustrate the difference. Meanwhile, in your own backyard, set up a flat mirror and shine it at a container filled with water. Get back to me when it starts to boil. I don't think youtube has footage length allowed that long though...

A flat mirror would be just annoying to look at. Focused rays of the sun via parabolic or fresnel are a whole other enchilada with hot sauce..

Here a discussion of the differences between focused sun and flat mirrors:

[ame="http://www.youtube.com/watch?v=o-eFwiraVv8"]Solar Hot Water System with a Parabolic Concentrator - YouTube[/ame]

They're using parabolics in all sorts of ways, but creating superheated steam is by far the most competitive as far as brute force for a centralized power plant like we are used to. This is what makes the parabolic solar thermal plant so attractive. You just plug it into the same grid system and use other sources only as a backup. Carbon footprint reduced. Nuclear is off the table.

Originally Posted by Silhouette

Someone is challenging that flat-mirrored reflection is better than parabolic or fresnel focusers.

Let's revisit the simple backyard experiment to illustrate the difference. Meanwhile, in your own backyard, set up a flat mirror and shine it at a container filled with water. Get back to me when it starts to boil.

Proving once again that solar energy is diffuse and hard to capture. Flat mirrors at large installations like Coalingua are a different bird, because the collector (on the tower top) is large enough to intercept all the reflected rays from each mirror.

Originally Posted by Silhouette

Here a discussion of the differences between focused sun and flat mirrors:

Solar Hot Water System with a Parabolic Concentrator - YouTube

OK, I looked at the video, and it didn't once compare flat mirrors to parabolics. The cost of this solar concentrating hot-water heater, by the way, is $23,500. The cost of a similar sized electric or gas water heater is $500.

Originally Posted by Silhouette

They're using parabolics in all sorts of ways, but creating superheated steam is by far the most competitive as far as brute force for a centralized power plant like we are used to.

A "centralized power plant like we're used to" works at night, and when it's cloudy. Try telling your ER docs they can't do surgeries at night and see how that flies.

Proving once again that solar energy is diffuse and hard to capture. Flat mirrors at large installations like Coalingua are a different bird, because the collector (on the tower top) is large enough to intercept all the reflected rays from each mirror.

Here's the funny thing, the linear tube is also large enough to capture all the concentrated solar rays along its length. NOT DIFFUSE, C-O-N-C-E-N-T-R-A-T-E-D. Another thing: the linear tube configuration with a concentrating solar thermal plant has a nice small internal volume on any given point of exposure, relative to its conductive surface area. So the second the sun hits those parabolic or fresnel focusers, you have a powerful ray of focused heat energy capable of cutting through steel if it's close enough & boiling water within seconds instead of hours or never. When was the last time you cut through steel or vitrified sand into glass with a flat mirror? These are things that concentrators can do.

Please stop. You're embarassing yourself again..

Here's the best design for solar thermal to go from 0-superheated steam that I can think of so far. Other folks might come up with something better. But if you hit that elongated tube, close to the ground with parabolics reflecting back up from the ground and fresnel focusing down from the top, you'd have that sucker pumping MW faster and more efficiently than that bogus Brightsource design, hands-down, no contest.

Well a member of the sham-solar-thermal group came out to play in their defense here: http://www.politicalforum.com/scienc...-plants-3.html

It was quite amusing. First "Herby" tried to denounce parabolics along a linear-tube target as "too expensive", claiming that the larger the parabolic dish, the more unwieldy and cost-inefficient it was. Then he went on to laud the advantages of Brightsource's design, which is a circle of flat mirrors focusing on a focal point hundreds of feet away.

When I pointed out that his extremely large parabolic dish was the most expensive and inefficient of all, the conversation sort of dropped away. What could he say? For that is precisely what the Brightsource design is.

Now, like I said over on that thread, at first I just found it amusing that Brightsource would design such a clearly inferior parabolic dish. It's impossible to clean and keep all the huge unwiedy flat mirrors reflecting at even 60% efficiency. The dust storms, atmosphere and so forth that those heat beams had to travel through, and the distance...means that system would be sluggish and expensive at best. Then when I learned Chevron was teamed up with Brightsource, a little lightbulb went on in my head. Team up with the competition visibly, then have the competition appear inferior in comparison to your power source [oil & natural gas in Chevron's case].

Clever. I submit though that the design in the diagram above is superior.

Originally Posted by Silhouette

Well a member of the sham-solar-thermal group came out to play in their defense here: http://www.politicalforum.com/scienc...-plants-3.html

It was quite amusing. First "Herby" tried to denounce parabolics along a linear-tube target as "too expensive", claiming that the larger the parabolic dish, the more unwieldy and cost-inefficient it was.

CSP is the most expensive power there is. Herby's exactly right.

Originally Posted by Silhouette

Then he went on to laud the advantages of Brightsource's design, which is a circle of flat mirrors focusing on a focal point hundreds of feet away.
When I pointed out that his extremely large parabolic dish was the most expensive and inefficient of all, the conversation sort of dropped away. What could he say? For that is precisely what the Brightsource design is.

All CSP is expensive and inefficient, compared to the alternatives.

Originally Posted by Silhouette

Now, like I said over on that thread, at first I just found it amusing that Brightsource would design such a clearly inferior parabolic dish. It's impossible to clean and keep all the huge unwiedy flat mirrors reflecting at even 60% efficiency.

It's much easier to clean a flat mirror than it is to clean a parabolic one, and much much easier to clean than a fresnel lens (they're a nightmare: the dust gets down inside those little grooves and won't come out). So no prizes there.

Originally Posted by Silhouette

Clever. I submit though that the design in the diagram above is superior.

I don't even see how that design can even work. The collecting pipe doesn't seem to move in response to the moving suntrackers. Which way is the pipe oriented? North-south, or east-west? How does the focal point of either mirror or lens stay on the non-moving collector in the face of the changing hourly geometry?

There's a north-facing arrow in the diagram.

I'm sorry if you don't know how to read a simple plan-diagram. And the key delineates what components track the sun and which don't. You might want to actually look at the design first before you attack it.