Large Scale Solar Energy Storage online by end of October

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EatenByLimestone

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It still amazes me that sunlight can be turned into an energy hot enough to create "molten salt". I haven't been able to process that in my noggin yet. How do you concentrate 150F or 200F into that kind of heat. What is the multiplier?
 
Very carefully! ==c

I would guess. The idea of "molten" anything conjures up evil characters in my head.
But really, I can't get my head around that...you can add all the 200F water to a pot that you want and you will not exceed 200F. How does 200F get turned into 1800F (or whatever "molten" temp it reaches)?
 
Very interesting! 10 months ago we installed a 10kW PV electric solar panels with micro inverters. One disadvantage of this system is that during a power outage the system shuts down. This is for safety reasons so the power from the solar panels would not feed into the grid and potentially electrocute someone working on the power lines nearby, and another reason is there is no place for the excess energy/power to go to. When the grid is up the excess power feeds back to it so the grid acts as a variable load dissipater. The unused power needs to get dissipated somewhere.
I was seriously debating on getting a battery backup installed, this way the excess power gets stored in the batteries and when the sun is out or during a power outage the power stored in the batteries could be used. The problem is that the battery backup cost almost $10k by itself, so it did not make sense to do it from a financial point of view. I opted on spending $1500 on a dual fuel generator (propane and fuel) and a manual transfer switch installed for the few days/weeks per year when there is a power outage.
I am still waiting for new cheaper battery technology to emerge one of these days...
 
It still amazes me that sunlight can be turned into an energy hot enough to create "molten salt". I haven't been able to process that in my noggin yet. How do you concentrate 150F or 200F into that kind of heat. What is the multiplier?
Mirrors
 
Concentrated sunlight is a heck of a lot hotter than 200 Deg
 
Concentrated sunlight is a heck of a lot hotter than 200 Deg
No doubt - those numbers are just my musings. How hot can mirrors make "black painted pipe" (from the article.)?
 
Hot enough to melt salt but not steel. Ever see those mirrors with the tall tower at the center? A few thousand degrees there i would assume. Edit: 1560 Degrees
 
Actually, no...I haven't, but have seen pics. I guess I need to do some homework. Need to find out the melting temp of salt.
 
801c melting point of salt. Solar tower goes up to 850c
 
Seems like it would be awful corrosive.
 
Seems like it would be awful corrosive.
Probably some hyper ceramic coatings or some such thing (speculation). High insulation value and can stand uber temps (like the space shuttle tiles).
 
I've seen these designs years ago. The heat needs to be high to get reasonable thermal eff in steam/elec production. And you need a phase change to store the heat (relatively) compactly, rather than having a huge tank and using 'sensible' heat. Various salts fit the bill, and there are plenty of metals and seals that work fine with it. One problem is the stuff solidifying in the pipes at night. IIRC they use a combination of circulating it to keep things warm, and 'drain back'.

Bottom line, roughly doubles the cost of a delivered kWh over no storage.
 
IIRC there is a similar project in Calif. or Nevada. I think I posted about this a couple years ago, but now can't find the thread.
 
Where I live, one of the three solar electric generation systems the power company has built for themselves uses ~500 acres of tracking parabolic reflectors shining at a vacuum tube insulated pipe containing a synthetic oil. The heated oil is used to generate steam. The oil gets to 748°F...

http://en.wikipedia.org/wiki/Martin_Next_Generation_Solar_Energy_Center
 
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