Energy from Solar Thermal

[wwswimming]

http://anz.theoildrum.com/node/3608#more

"The system contains almost 7200 mirrors, which will guide the sun's rays into holes in the bottoms of 54 elevated graphite cubes, heating them to 1800 degrees"

one of the more thorough reviews i've seen of ongoing research
into solar thermal and wind (energy sources ) and related energy
storage technologies (Molten salt storage and Room Temperature
Ionic Liquids, Concrete/cerami Storage & Phase Change Materials).

some interesting energy research out in Tasmania.

 

[Crusty]

Whatever happened to the guy who was going to build a huge vertical tunnel in the Outback with some large flat plane under it to try and capture more solar effects. I totally forget the details, but seems somewhat similar to this but a lot simpler from what I remember.

I think it relied on warming up water which would cause convection currents to rise up the tunnel which would have turbine based generators inside of it.

 

[BrownTown]

Well the basic idea is the same as all the other solar thermal installations, the graphite blocks are maybe a little different, usually you see molten salt or something like that. However the idea of storing solar energy in these means is just silly. Solar power is already very uneconomical, further reducing the efficiencies and reliability and greatly increasing the cost and with storage techniques is 100% worthless. Storage of solar energy would only be needed if solar was to account for >~30% of energy capacity which it won't anytime soon. As such you can be fine just running the solar installations during the day (when demand is highest) to meet the peaks and just have your base load generation (nuclear) going 24/7 to take on the nighttime demand like it already does.

 

[bobsmith1492]

Originally posted by: BrownTown
Well the basic idea is the same as all the other solar thermal installations, the graphite blocks are maybe a little different, usually you see molten salt or something like that. However the idea of storing solar energy in these means is just silly. Solar power is already very uneconomical, further reducing the efficiencies and reliability and greatly increasing the cost and with storage techniques is 100% worthless. Storage of solar energy would only be needed if solar was to account for >~30% of energy capacity which it won't anytime soon. As such you can be fine just running the solar installations during the day (when demand is highest) to meet the peaks and just have your base load generation (nuclear) going 24/7 to take on the nighttime demand like it already does.

There are easier ways to store power anyway, such as pumped-water storage.

 

[silverpig]

Originally posted by: bobsmith1492

Originally posted by: BrownTown
Well the basic idea is the same as all the other solar thermal installations, the graphite blocks are maybe a little different, usually you see molten salt or something like that. However the idea of storing solar energy in these means is just silly. Solar power is already very uneconomical, further reducing the efficiencies and reliability and greatly increasing the cost and with storage techniques is 100% worthless. Storage of solar energy would only be needed if solar was to account for >~30% of energy capacity which it won't anytime soon. As such you can be fine just running the solar installations during the day (when demand is highest) to meet the peaks and just have your base load generation (nuclear) going 24/7 to take on the nighttime demand like it already does.

There are easier ways to store power anyway, such as pumped-water storage.

I think flywheels are great for short term storage...

 

[BrownTown]

Originally posted by: silverpig

Originally posted by: bobsmith1492

Originally posted by: BrownTown
Well the basic idea is the same as all the other solar thermal installations, the graphite blocks are maybe a little different, usually you see molten salt or something like that. However the idea of storing solar energy in these means is just silly. Solar power is already very uneconomical, further reducing the efficiencies and reliability and greatly increasing the cost and with storage techniques is 100% worthless. Storage of solar energy would only be needed if solar was to account for >~30% of energy capacity which it won't anytime soon. As such you can be fine just running the solar installations during the day (when demand is highest) to meet the peaks and just have your base load generation (nuclear) going 24/7 to take on the nighttime demand like it already does.

There are easier ways to store power anyway, such as pumped-water storage.

I think flywheels are great for short term storage...

In terms of cost that is probably true, however solars problems are a 24 hour cycle, flywheels are good for seconds or maybe minutes. Right now in terms of short term storage capacitors are used in order to make up for momentary voltage sags and such. IF you want to get into grid level energy storage its pumped hydro.

Just FWIW pumped storage is a very cool thing to see working, the Racoon Maountain pumped water storage facility is only a few miles from my house and it is a pretty cool thing to see (unfortnautely you can't go underground anymore after 9-11, but you can see the lake still). Anyways, that facility could provide all the electricty for a city like Chattanooga (where it is located) for 24 hours. Also working at TVA you can see when they switch units at Raccoon Maountain in as pumps or generators on the displays and you can see in the morning they are pumping water up the mountain like crazy, and then when it starts getting hot and everyone cranks up the AC they switch it in as a generator and it save TVA litterally a million dollars a day simply because energy is cheaper at night than during the day. Pumped storage is the ONLY economically feasible grid level energy storage technique at this point in time. Just to put it into perspective, the amount of energy stored by the Racoon Mountain facility is greater than that of the Hiroshima bomb (according to my calculations which I can present if you disagree).

EDIT (maths):

32 gigawatt hour = 27.533 460 803 072 kiloton [explosive] (online conversions)

 

[silverpig]

I heard about a guy who powered himself off of solar entirely all year long. He used flywheels to store the excess power during the day for usage overnight, and batteries to store the summer's excesses through the winter...

I also know that turbopumps can take at least several minutes to spin down with mechanical bearings and a slowly increasing internal pressure... I'd imagine flywheels could do much better.

 

[Gibsons]

In an apples and oranges comparison, and maybe even derailing the topic, you'll grow old waiting for ultracentrifuges to spin down when you can't use the brakes on them. Basically a several kg hunk of titanium spinning at 20-50k rpm in a fairly hard vacuum.

The energy in something like that is considerable... When things go wrong, it can be pretty spectacular. Text

 

[Ticky]

Heck, let's just skip straight to orbital-ring energy storage.

What, you've never heard of it? Simple, you get a band of super-tensile material, put a whole series of super-conductor magnets spaced around it, and put it out in space (in a sort of fake orbit). Then, around the equator of the planet (or moon) you put a nice linear motor. When you have extra energy, spin the ring up. When you need enery, spin it down. Energy can be added or taken out at any point along the equator. And you've already removed the planet's natural magnetic field, so that's not a problem, and the ring provides a nice new one.

What, we don't have the technology for that? Bah.

 

[Stiganator]

Originally posted by: Gibsons
In an apples and oranges comparison, and maybe even derailing the topic, you'll grow old waiting for ultracentrifuges to spin down when you can't use the brakes on them. Basically a several kg hunk of titanium spinning at 20-50k rpm in a fairly hard vacuum.

The energy in something like that is considerable... When things go wrong, it can be pretty spectacular. Text

My chemistry professor told us about some grad students who nuked a room with an ultracentrifuge back in the day. 200,000 RPM+ unbalanced = bad times.