mersenneforum.org

mersenneforum.org (https://www.mersenneforum.org/index.php)
-   Science & Technology (https://www.mersenneforum.org/forumdisplay.php?f=52)
-   -   Green-Energy Feasibility for the Amundsen-Scott South Pole Station (https://www.mersenneforum.org/showthread.php?t=25733)

kriesel 2020-07-10 20:31

Green-Energy Feasibility for the Amundsen-Scott South Pole Station
 
[EWM - Mod note: Thread split off [url=https://mersenneforum.org/showthread.php?t=24979]from here[/url] as interesting-but-off-topic subdiscussion.]

[QUOTE=chalsall;550214]I envy you... BB VAT is 15%. And our power is still 99% generated by burning long-dead plants and animals, so we pay a large amount for our electrons...[/QUOTE]IIRC, electricity at the South Pole Station is generated by diesel engines, and the fuel had delivered cost ~$20/gallon, which would contribute about $1.22/KWHR at 40% efficiency since it's all delivered by air freight. The last supply flight of the season, the supply plane may not even touch down and does not power down (the pilot and copilot do not plan to stay the winter and don't risk a failure to restart engines), they just open the cargo door at very low altitude and push crates of "freshies" (fresh edibles) out the back. It sleds to a stop and the few researchers that will over-winter gather it and bring it inside before it freezes solid. Some research hardware is also delivered by this approach, of get close to the runway and push it out the back. That places extra demands on packaging and instrument design.

The generators that provide drinking water by melting subsurface ice, electricity, and heat are regarded as necessary for survival. When the generators stop, everyone may become an assistant diesel mechanic.
It's a pity electricity, food, housing, etc. costs so much there. The cooling available is excellent.

chalsall 2020-07-10 20:44

[QUOTE=kriesel;550223]It's a pity electricity, food, housing, etc. costs so much there. The cooling available is excellent.[/QUOTE]

LOL!!! :tu:

It's interesting -- Barbados (and, of course, all of the tropical landmasses) have the exact opposite problem(s).

What drives me nuts is we have been so resistant to using the fusion reactor in the sky. The reason, of course, comes from long-term investments in the carbon-based plant by the sole power provider here (BL&P), enabled by a totally impotent (if not outright, Ummm...) "regulator". (Friends of mine and I call them the "Fsck The Consumer" (FTC); there's nothing fair about their decisions...)

I understand the economics; you don't write down hundreds of millions except over decades. But get with the program, will you??? The future's coming fast; deal with it.

ewmayer 2020-07-10 20:49

[QUOTE=kriesel;550223]It's a pity electricity, food, housing, etc. costs so much [at the South Pole Station]. The cooling available is excellent.[/QUOTE]

At least for the part of the year that the sun is visible, it would seem an ideal location for a solar-power array, suitably cold-temperature and high-wind hardened, naturally. Since Antarctica is a desert and an otherwise very-low-dust environment, keeping the panels clean of snow and dust would be easier there than just about anywhere else on earth. That summer-generating capacity would free up shipping room for laying in diesel for the coming long winter.

Aha, I see [url=https://ir.canterbury.ac.nz/handle/10092/14220]others with the same thought[/url] are already [url=http://www.southpolestation.com/0809/solarenergyatpole012209rsa.pdf]on the case[/url].

Uncwilly 2020-07-10 22:03

If they bring in extra solar capacity, during the summer they can locally generate H[SUB]2[/SUB] from the ice. That can be stored in tanks until the winter comes and then be used to make electricity. Having the tanks cold would help with capacity. If fuel cells are used to make e[SUP]-[/SUP] then they will have warm water without spending extra power to melt ice.

chalsall 2020-07-10 22:17

[QUOTE=Uncwilly;550226]If they bring in extra solar capacity, during the summer they can locally generate H[SUB]2[/SUB] from the ice. That can be stored in tanks until the winter comes and then be used to make electricity.[/QUOTE]

I don't have the time to dig up references, but a lot of interesting work is currently being done with regards to chemical storage of energy using less volatile reagents.

H[SUB]2[/SUB] is a capricious little beast! (As is C[SUB]2[/SUB]H[SUB]2[/SUB], I discovered empirically...)

kriesel 2020-07-10 22:51

[QUOTE=ewmayer;550225]At least for the part of the year that the sun is visible, it would seem an ideal location for a solar-power array, suitably cold-temperature and high-wind hardened, naturally. Since Antarctica is a desert and an otherwise very-low-dust environment, keeping the panels clean of snow and dust would be easier there than just about anywhere else on earth. That summer-generating capacity would free up shipping room for laying in diesel for the coming long winter.

Aha, I see [URL="https://ir.canterbury.ac.nz/handle/10092/14220"]others with the same thought[/URL] are already [URL="http://www.southpolestation.com/0809/solarenergyatpole012209rsa.pdf"]on the case[/URL].[/QUOTE]A 1050W array producing 65KWhr/week works out to about 37% of rated opwer, in this near ideal environment with lots of crystalline snow scattering sunlight incident on the surface and illuminating what would otherwise be shaded panels. The horizontal panel is basically wasted, so no more than about 80% is to be expected. A rotating flat array would be better.

I see in that latter link they used a $30/gallon fuel delivered cost. So bump that $1.22/kwhr I posted earlier, up to $1.83.

During the installation of the Ice Cube neutrino detector, each of the 80+ 2.4-km-deep holes drilled with hot water over 24-40 hours took initially about 7000 gallons fuel. With experience and additional equipment, we reduced that to around 5000 gallons fuel per hole. The top part, that does not hold water because it's too porous, is called firn. A closed loop propylene glycol system with a bank of 6 30KW-rated electric heater elements was develoed and used to predrill through the firn more efficiently than the deep hole drill could do firn. The firn drill was about the size of an RV The main drill system was the size of several cargo-plane-limited modules, with some assembly done at South Pole Station. The holes drilled were just big enough to fall into if standing. Occasionally the drillers would hit solid material, and rarely be forced to abandon a hole. If it was any sort of plant matter they called it "salad"; deep frozen animals were called "pork". [URL]https://icecube.wisc.edu/[/URL]

Re generating hydrogen as energy storage, electrolysis is inefficient, and recovering electrical energy via fuel cell is also inefficient. Hydrogen is miserably difficult to store economically. And I say that as someone who's been interested in alternative energy for about half a century. A fundamental issue is that while flames (typical power plant turbines, boilers, IC engines) employ bulk volume processes, electrolysis and its catalytic reverse are surface phenomena. This difference drives energy conversion density and capital costs. Also, extracting water produced is a chore; do NOT drink the electrolyte.
[URL]https://www.sciencedirect.com/science/article/pii/S0360319917339435[/URL]
Hydrogen fuel cell systems are particularly bad in mobile applications, so bad that fuel cell electric vehicles are suggested to be hybrid with batteries. This gives an efficiency around 30%; [URL]https://insideevs.com/news/406676/battery-electric-hydrogen-fuel-cell-efficiency-comparison/[/URL]

Uncwilly 2020-07-11 01:59

[QUOTE=chalsall;550227]I don't have the time to dig up references, but a lot of interesting work is currently being done with regards to chemical storage of energy using less volatile reagents.[/QUOTE]The issue is that at 90° S there is loads of H[SUB]2[/SUB]O that is ready to be split for storage. And there are 2 potential ways to get electrons out of it. With other options, C has to be supplied. Cargo flights would have to bring in the atoms. The whole idea is not to ship atoms.:wink:

chalsall 2020-07-11 14:16

[QUOTE=Uncwilly;550242]The whole idea is not to ship atoms.:wink:[/QUOTE]

Well, more accurately, to ship as few atoms as possible... :wink:

The ideas being worked involve having chemical agents (usually in solution, so the H[sub]2[/sub]O can be sourced locally) and a bi-directional reactor to change their states. Basically a really big rechargeable battery, with plumbing...

Point being, the reagents are reused rather than consumed. Ship once; use often.

ewmayer 2020-07-12 22:13

[QUOTE=chalsall;550269]Well, more accurately, to ship as few atoms as possible... :wink:

The ideas being worked involve having chemical agents (usually in solution, so the H[sub]2[/sub]O can be sourced locally) and a bi-directional reactor to change their states. Basically a really big rechargeable battery, with plumbing...

Point being, the reagents are reused rather than consumed. Ship once; use often.[/QUOTE]

Similar thought occurred to me. Assuming for the moment that the obvious environmental concerns could be mitigated, let's consider how big an old-fashioned-but-cheap-and-scalable [url=https://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery]lead-acid battery[/url] we'd need to store the annual power needed by the station: for this kind of battery, energy density is close to 100Wh/L, or 100kWh/m^3 of water.

Per [url=https://www.pdceng.com/projects/south-pole-power-plant/#content]this article[/url] the current station power plant has three 1MW diesel generators. It's not clear what the average-load during the winter is, but we can estimate this via other means. [url=https://www.jeffreydonenfeld.com/blog/2012/12/the-south-pole-power-plant/]This article[/url] says "Our lives are governed by 600,000 gallons of AN8 jet fuel." Per [url=https://www.convertunits.com/from/kWh/to/gallon+%5BU.S.%5D+of+diesel+oil]here[/url] a gallon of diesel (more or less same as jet fuel and kerosene) represents 40kWh of energy, thus - assuming similar conversion efficiencies for diesel-generator-to-kWh and lead-acid-chemicals-to-kWh, the foregoing annual fuel requirement is equivalent to 24,000MWh. There are 8760 hours per year, so that would imply the generators are running at near 100% capacity 24/7/365, which seems improbable. But, we're order-of-magnitude-estimating here.

24,000MWh translates to a giant lead-acid battery of 240,000m^3 volume, so, say, an acid-filled "swimming pool" roughly 60m on a side. That would need to be lined with thick polyethylene or similar, and likely need at least some insulation to prevent freezing, though the waste charge/discharge heat would help with that. The lead requirement (or whatever metal) for the terminals would not be proportionally large, because the liquid part of the battery stores a full year's worth of power: the max continuous-power requirement is 'just' 3MW.

kriesel 2020-07-12 23:38

[QUOTE=ewmayer;550384]Per [URL="https://www.convertunits.com/from/kWh/to/gallon+%5BU.S.%5D+of+diesel+oil"]here[/URL] a gallon of diesel (more or less same as jet fuel and kerosene) represents 40kWh of energy, thus - assuming similar conversion efficiencies for diesel-generator-to-kWh and lead-acid-chemicals-to-kWh, the foregoing annual fuel requirement is equivalent to 24,000MWh. There are 8760 hours per year, so that would imply the generators are running at near 100% capacity 24/7/365, which seems improbable. But, we're order-of-magnitude-estimating here.[/QUOTE]
I think the conversion link you used is without allowing for engine efficiency. BSFC figures in different units and engine thermal efficiences for an assortment of engines are [URL="https://en.wikipedia.org/wiki/Brake-specific_fuel_consumption"]here[/URL]. The difference looks to be about a binary order of magnitude.

Similarly, lead-acid or other batteries have efficiency curves. [URL]https://www.solar-facts.com/batteries/battery-charging.php[/URL]

ewmayer 2020-07-12 23:59

[QUOTE=kriesel;550398]I think the conversion link you used is without allowing for engine efficiency. BSFC figures in different units and engine thermal efficiences for an assortment of engines are [URL="https://en.wikipedia.org/wiki/Brake-specific_fuel_consumption"]here[/URL]. The difference looks to be about a binary order of magnitude.[/QUOTE]

2x is within my back-of-envelope-figuring tolerance - was aiming for a gross "is this remotely feasible?" Plus I stated "assuming similar conversion efficiencies for diesel-generator-to-kWh and lead-acid-chemicals-to-kWh". Per wikipedia the latter tech's charge/discharge efficiency is 50-95%, not clear if that applies to *either* the charge or discharge phase or the round-trip, but figuring the kind of challenging environment our swimming-hole battery would be in, the 50% end of the range might well be optimistic. Diesel-generators have one added advantage: in the Antarctic, the "waste heat" is not in fact wasted, but put to excellent use heating the well-insulated habitation and other station modules. For the pool-in-the-ice ginormo-battery, any waste heat would be needed to help keep the electrolyte from freezing, even with pool which is well-insulated all around. But I'll let someone else do the detailed "assume a 60x60x60m pool insulated with 10cm styrofoam (which could be delivered as binary liquid in barrels and foamed in place), sunk into the Antarctic ice with top at 'ground' level. How many W are needed to keep the pool from freezing at an air temperature of -60C (= guess at the average winter temperature - pool that big doesn't care about day-to-day variations)?" calculation.


All times are UTC. The time now is 23:44.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.