Scrutable

bjn wrote: Tue Sep 29, 2020 9:07 am The Dogger Bank windfarm is progressing apace. GE just signed the contracts to supply 190 13MW turbines, they have 220m rotors! That just for the first 2 of 3 phases, and will supply 2.5GW peak by 2026. Will Hinkley C even be finished by then?

As an aside, I'm all in favour of windfarms in as much of the sea as possible, as they must prevent the worst sort of trawling. As well as act as mini reefs

jimbob wrote: Tue Sep 29, 2020 8:39 pm

bjn wrote: Tue Sep 29, 2020 9:07 am The Dogger Bank windfarm is progressing apace. GE just signed the contracts to supply 190 13MW turbines, they have 220m rotors! That just for the first 2 of 3 phases, and will supply 2.5GW peak by 2026. Will Hinkley C even be finished by then?

As an aside, I'm all in favour of windfarms in as much of the sea as possible, as they must prevent the worst sort of trawling. As well as act as mini reefs

Green peace was recently dumping huge boulders in the area to snag illegal trawlers. Hopefully this will put the buggers off and offer a haven for a range of wildlife.

The impact on fisheries has been noted by marine biologists (can dig out refs if that would be of interest), with effects including not only higher fish populations but increased cetacean and seabird densities too IIRC.

I think many fishing activities avoid wind farms, because of the difficulty of manoeuvring around all the windmills. And we're learning how to site, position and accessorise them so they don't chop up too many migrating birds and bats, so they're a decent net win for biodiversity.

Trawling should be banned everywhere. We don't raze entire habitats to the ground to hunt food anywhere else (apart from grouse moors, though they're shot more for entertainment than food production).

bjn wrote: Tue Sep 29, 2020 9:50 pm

jimbob wrote: Tue Sep 29, 2020 8:39 pm

bjn wrote: Tue Sep 29, 2020 9:07 am The Dogger Bank windfarm is progressing apace. GE just signed the contracts to supply 190 13MW turbines, they have 220m rotors! That just for the first 2 of 3 phases, and will supply 2.5GW peak by 2026. Will Hinkley C even be finished by then?

As an aside, I'm all in favour of windfarms in as much of the sea as possible, as they must prevent the worst sort of trawling. As well as act as mini reefs

Green peace was recently dumping huge boulders in the area to snag illegal trawlers. Hopefully this will put the buggers off and offer a haven for a range of wildlife.

Glad to hear that they've learnt something in the 25 years since Brent Spar, then.

For clarity. I hope the windmills will put the buggers off.

Bird on a Fire wrote: Wed Sep 30, 2020 12:01 am The impact on fisheries has been noted by marine biologists (can dig out refs if that would be of interest), with effects including not only higher fish populations but increased cetacean and seabird densities too IIRC.

I think many fishing activities avoid wind farms, because of the difficulty of manoeuvring around all the windmills. And we're learning how to site, position and accessorise them so they don't chop up too many migrating birds and bats, so they're a decent net win for biodiversity.

Trawling should be banned everywhere. We don't raze entire habitats to the ground to hunt food anywhere else (apart from grouse moors, though they're shot more for entertainment than food production).

Yup, there was the beautiful image I mentioned about the start of this forum:

jimbob wrote: Wed Dec 25, 2019 11:38 pm One of my favourite papers from 2014.

https://www.cell.com/current-biology/fu ... 14)00749-0

the satellite tracks in figure 1 is beautiful

Ah I remember reading that now. Super cool, thanks jimbob.

On a side note - would this interest anyone: ‘Perceptions of nuclear power – it’s not (just) about the science’

FlammableFlower wrote: Wed Sep 30, 2020 12:51 pm On a side note - would this interest anyone: ‘Perceptions of nuclear power – it’s not (just) about the science’

Thanks for that. Don’t know if I’ll be able to make that time but I’ll try.


Back on the subject of hydrogen, we were talking earlier about a pressure tank for gaseous hydrogen because of an analogy with the Toyota Mirai. How about a cryogenic tank for liquid hydrogen? Yes it would be big, but insulation isn’t heavy. I’d have thought a ship might be capable of taking such a tank.

Grumble wrote: Wed Sep 30, 2020 5:15 pm

FlammableFlower wrote: Wed Sep 30, 2020 12:51 pm On a side note - would this interest anyone: ‘Perceptions of nuclear power – it’s not (just) about the science’

Thanks for that. Don’t know if I’ll be able to make that time but I’ll try.


Back on the subject of hydrogen, we were talking earlier about a pressure tank for gaseous hydrogen because of an analogy with the Toyota Mirai. How about a cryogenic tank for liquid hydrogen? Yes it would be big, but insulation isn’t heavy. I’d have thought a ship might be capable of taking such a tank.

We did already mention that a bit. NASA has lots of them, including new systems

dyqik wrote: Wed Sep 30, 2020 5:33 pm

Grumble wrote: Wed Sep 30, 2020 5:15 pm

FlammableFlower wrote: Wed Sep 30, 2020 12:51 pm On a side note - would this interest anyone: ‘Perceptions of nuclear power – it’s not (just) about the science’

Thanks for that. Don’t know if I’ll be able to make that time but I’ll try.


Back on the subject of hydrogen, we were talking earlier about a pressure tank for gaseous hydrogen because of an analogy with the Toyota Mirai. How about a cryogenic tank for liquid hydrogen? Yes it would be big, but insulation isn’t heavy. I’d have thought a ship might be capable of taking such a tank.

We did already mention that a bit. NASA has lots of them, including new systems

I must have skipped over that part of the thread. That NASA system looks good, presumably it might make sense to use hydrogen to generate electricity to provide refrigeration rather than lose it to evaporation, if you were using it on a ship.

bjn wrote: Fri Sep 18, 2020 4:38 pm H2 is just horrid stuff to use for any form of transportation fuel, it's hard to store, it's expensive to generate electrically and a pain to distribute/transport. I'm not buying it for any form of land transportation, and I have severe doubts about its utility in marine transportation.

A large container ship has something like 16,000 m^3 of fuel oil, which is roughly 16,000 tonnes. Assuming a fuel cell instead of burning the H2, and allowing fudge factors for differences in efficiency, you need about 5,000 tonnes of H2 to get the equivalent amount of energy spinning your propellers. Now if that is kept as liquid H2, it needs something like 3.5X the volume of your fuel oil, but you need to keep that liquid H2 at −252.87 °C. I don't see that working for weeks at sea.

dyqik wrote: Wed Sep 30, 2020 5:33 pm

Grumble wrote: Wed Sep 30, 2020 5:15 pm on the subject of hydrogen, we were talking earlier about a pressure tank for gaseous hydrogen because of an analogy with the Toyota Mirai. How about a cryogenic tank for liquid hydrogen? Yes it would be big, but insulation isn’t heavy. I’d have thought a ship might be capable of taking such a tank.

We did already mention that a bit. NASA has lots of them, including new systems

I seem to have forgotten the first mention of liquid H2 in BJN’s post. The NASA refrigerated tank would seem to challenge the safety of the assumption bjn made there. It would be really interesting to see if anyone’s working on that.

Liquid hydrogen carrier.
The hydrogen in this case isn’t being used as a fuel by the ship, and it’s “only” going from Australia to Japan, but it will be interesting to see the results of the trials.

Grumble wrote: Thu Oct 01, 2020 10:47 am

bjn wrote: Fri Sep 18, 2020 4:38 pm H2 is just horrid stuff to use for any form of transportation fuel, it's hard to store, it's expensive to generate electrically and a pain to distribute/transport. I'm not buying it for any form of land transportation, and I have severe doubts about its utility in marine transportation.

A large container ship has something like 16,000 m^3 of fuel oil, which is roughly 16,000 tonnes. Assuming a fuel cell instead of burning the H2, and allowing fudge factors for differences in efficiency, you need about 5,000 tonnes of H2 to get the equivalent amount of energy spinning your propellers. Now if that is kept as liquid H2, it needs something like 3.5X the volume of your fuel oil, but you need to keep that liquid H2 at −252.87 °C. I don't see that working for weeks at sea.

dyqik wrote: Wed Sep 30, 2020 5:33 pm

Grumble wrote: Wed Sep 30, 2020 5:15 pm on the subject of hydrogen, we were talking earlier about a pressure tank for gaseous hydrogen because of an analogy with the Toyota Mirai. How about a cryogenic tank for liquid hydrogen? Yes it would be big, but insulation isn’t heavy. I’d have thought a ship might be capable of taking such a tank.

We did already mention that a bit. NASA has lots of them, including new systems

I seem to have forgotten the first mention of liquid H2 in BJN’s post. The NASA refrigerated tank would seem to challenge the safety of the assumption bjn made there. It would be really interesting to see if anyone’s working on that.

I've fixed the quotes - I think some browsers seem to turn the post time id into a telephone number - so I just deleted that bit out and it sorted it

Thanks Stephanie, bit of an obscure one that.

Grumble wrote: Thu Oct 01, 2020 10:53 am Liquid hydrogen carrier.
The hydrogen in this case isn’t being used as a fuel by the ship, and it’s “only” going from Australia to Japan, but it will be interesting to see the results of the trials.

Here’s a better link that includes stuff about the infrastructure at either end of the trip as well as the carrier itself.

https://hydrogenenergysupplychain.com/category/news/

Grumble wrote: Thu Oct 01, 2020 10:53 am Liquid hydrogen carrier.
The hydrogen in this case isn’t being used as a fuel by the ship, and it’s “only” going from Australia to Japan, but it will be interesting to see the results of the trials.

From your link:

The carrier will transport to Japan hydrogen produced in Australia from cheap coal ...

contradiccting the claim that this will reduce carbon emissions.

bmforre wrote: Thu Oct 01, 2020 5:43 pm

Grumble wrote: Thu Oct 01, 2020 10:53 am Liquid hydrogen carrier.
The hydrogen in this case isn’t being used as a fuel by the ship, and it’s “only” going from Australia to Japan, but it will be interesting to see the results of the trials.

From your link:

The carrier will transport to Japan hydrogen produced in Australia from cheap coal ...

contradiccting the claim that this will reduce carbon emissions.

That would Shirley depend on whether it was coupled with some form of CCS.

I assume it is easier to recapture carbon at the production site than it would be to do it to a diesel-powered ship on the open seas.

Carbon capture and storage in Australia

There are no currently-operating large-scale CCS projects in Australia, although the Gorgon gas project will qualify when it is fully operational. Despite multiple CCS demonstration projects at Australian coal-fired power stations, none of Australia's coal plants are currently capturing CO2
or have a time frame for doing so. Australian Treasury modelling finds that CCS is not expected to be commercially viable until the 2030s.

bmforre wrote: Thu Oct 01, 2020 5:43 pm

Grumble wrote: Thu Oct 01, 2020 10:53 am Liquid hydrogen carrier.
The hydrogen in this case isn’t being used as a fuel by the ship, and it’s “only” going from Australia to Japan, but it will be interesting to see the results of the trials.

From your link:

The carrier will transport to Japan hydrogen produced in Australia from cheap coal ...

contradiccting the claim that this will reduce carbon emissions.

Absolutely, I’m not really a fan of hydrogen production from fossil fuels in terms of green power, and that is almost all hydrogen currently. I’m more interested in the tank and transporting liquid hydrogen at sea.

I believe the suggestion by proponents is that excess power from wind or solar could be used for electrolysis to produce green hydrogen.

The main thing with hydrogen is that it's the equivalent of battery technology, not power generation technology - it's a storage and transmission technology. It helps in the same ways as electric cars and battery development, in that it allows centralization of power generation. You still need to do the modal shift at the generation end, whether that's CCS, change of source, etc.

dyqik wrote: Thu Oct 01, 2020 6:19 pm The main thing with hydrogen is that it's the equivalent of battery technology, not power generation technology - it's a storage and transmission technology. It helps in the same ways as electric cars and battery development, in that it allows centralization of power generation. You still need to do the modal shift at the generation end, whether that's CCS, change of source, etc.

Exactly

jimbob wrote: Thu Oct 01, 2020 8:45 pm

dyqik wrote: Thu Oct 01, 2020 6:19 pm The main thing with hydrogen is that it's the equivalent of battery technology, not power generation technology - it's a storage and transmission technology. It helps in the same ways as electric cars and battery development, in that it allows centralization of power generation. You still need to do the modal shift at the generation end, whether that's CCS, change of source, etc.

Exactly

It could be a good way of using up excess wind power output from stormy winter nights, especially as electrolysis plants would probably cope pretty well with fluctuating supply.

This sort of tech makes it more interesting for a country with lots of windy coastlines:

https://news.stanford.edu/2019/03/18/ne ... l%20energy.

jimbob wrote: Thu Oct 01, 2020 8:45 pm

dyqik wrote: Thu Oct 01, 2020 6:19 pm The main thing with hydrogen is that it's the equivalent of battery technology, not power generation technology - it's a storage and transmission technology. It helps in the same ways as electric cars and battery development, in that it allows centralization of power generation. You still need to do the modal shift at the generation end, whether that's CCS, change of source, etc.

Exactly

One of the main downsides is that H2 is very inefficient, and therefore expensive, way to store electricity. Currently it's something like only a 1/3* as efficient as a decent lithium battery, there are losses in cracking the H2, losses in the fuel cell, and losses in liquify and/or compressing it. That's why I don't see it being at all useful for any form of ground transportation. Possibly for flight or rockets where the kWh/kg thing is significant, but your planes will have limited space in the fuselage due to the cryogenic tanks, which will in aggregate still be heavier than hydrocarbon equivalents (fuel + tank). Flying such things will not be cheap.

From my limited understanding, electrolysis machines are expensive to purchase and you want them running as much as possible to pay off the capital. So only running when there is excess supply may not be viable, some spreadsheet would show the relevant prices for electricity/capital to make it worth while. Also, if using it as storage, you are only going to get 1/3 back compared to a battery.

*Yes, citation required, CBA at the moment, about to go to bed.

bjn wrote: Thu Oct 01, 2020 10:41 pm Possibly for flight or rockets where the kWh/kg thing is significant, but your planes will have limited space in the fuselage due to the cryogenic tanks, which will in aggregate still be heavier than hydrocarbon equivalents (fuel + tank). Flying such things will not be cheap.

Its worse than that for planes unfortunately. Liquid fossil fuels used currently have the wonderful property of their tanks being able to conform to almost any shape you like. This makes filling with fuel awkward shaped and hard to access places like the inside of a wing super easy, leaving easier to reach spaces like in the fuselage free for freight (and humans, the self-loading variety of freight).

As soon as you need to make your tanks into pressure vessels, you're losing that big advantage, and it is going to cut the fuel volume that can be stored (which is already now of lower energy density as discussed up-thread), significantly increase the structural weight to make non-cylindrical pressure vessels, and/or massively cut into the convenient volume that you want to put revenue-earning payload. Probably a mix of the three.

This change is necessary, but those operators that don't see getting with the program to be advantageous to them are going to make a colossal stink.