Backyard Aquaponics
A place to discuss aquaponics

Apparently solar heat + salt is the way of the future:

http://inhabitat.com/worlds-first-molte ... -at-night/

Allows you to generate solar energy at night (because the salt retains the heat over night, and does it better than oils!)

Right, the molten salt heats to around 1000* and holds that heat much longer then the oils generaly used in CPS plants. The salt is used to boil water producing Steem in order to turn the steem turbines. So it will still produce energy even after the sun goes down but only till the salt cools and no longer produces steem. Then other energy generation methods would be required.

I think they're saying that the salt can almost last until the next day...

Just that it runs longer with the salt than oil. The salt retains the heat longer but not though out the night. It is only 1000* and that heat is being transfered to water in order to boil it to produce the steem. So them temp of the salt is being pulled down by the water. Even the water is warmed by passing it throught the steem, it will cycle down long before sun rise.

Perpetual motion and free energy would be nice, but alas this is not it.

Certainly it could all be sized appropriatly to run through the night. More mirrors, more salt and smaller generators...it is just a payoff. Seeing that the majority of energy is used during the day though, they are probably just sized to supplement daytime usage. Which when you think about it, seems perfectly reasonable.

Yah, I understand this, but these guys reckon it's going to last most of the night:
"...allow enough of the sun's heat to be stored that the power plant can pump out electricity for nearly eight hours after the sun starts to set. "It's enough for 7.5 hours to produce energy with full capacity of 50 megawatts," says Sven Moorman"

http://www.scientificamerican.com/artic ... y-at-night

Producing for a few hours before and after sunset, when PV would produce little or nothing, could be a real winner as far as load matching. There is fairly high power use until about bedtime, then it drops way down to the point that some baseload producers here (coal plants etc) send out power for free or even a negative price. Of course, once transmission is factored in the cost is positive, but still very low.

eh?? molten salt technology is nothing to do with perpetual motion.

it's a sound way to produce large base load from the sun. and no it doesn't run out of steam after an hour or 2 past sun down. andasol 1 in spain is operational since 2010 and it produces 50 megawatts, and can do so after dark for 7.5 hours at FULL load. i'd hazard a guess that they only budgeted for 7.5 hours full load, because in the dead of night they don't need to run at full power

andasol 2 which comes on line soon is 150megwatts.

*grin*
I assume you are questioning "There is fairly high power use until about bedtime, then it drops way down to the point that some baseload producers here (coal plants etc) send out power for free or even a negative price"

I certainly don't mean that they can produce power at a profit at those prices, but it is so hard to shut down some baseload plants for an hour or two (or even minutes) at lowest demand that it is more economically sensible for them to essentially pay someone to take the power. They make it up when demand rises.

This is something you will see when different entities own the power plant and transmission lines. I'm talking instantaneous price at the point power enters the transmission grid.

No I believe he's referring to Aquaman2000's "Perpetual motion and free energy would be nice, but alas this is not it." (which I also thought was a bit of a weird statement seeing as I had never heralded it as such)

On a smaller scale you could heat a ft or a green house.

... yep... by the time you paid for the solar concentrator, steam turbine, salt tanks, plumbing and the potassium nitrate... (try getting that one past the authorities)...

It would probably be cheaper to run a propane heating system...

Thinking more along the lines of a fresnel lens and heat exchange to a storage tank for heating. Low tech.