Sorry, this is your "physics"?
Edit: just to be clear but there's an entire paper published in a high profile journal, peer-reviewed, and and the comment is "nuh uh" while appealing to non-existent physics principles to try to fake authority.
And BTW, there has been a zero emissions solution to this problem for thousands of years: sail-ships. The fact that we don’t use sail-ships reveals where the problem lie.
> Under the near-future scenario, the TCP of battery-electric shipping is lower than that of the incumbent ICE ship at ranges around 3,000 km for all ship classes.
Science is one of those topics that HN does not do very well. Every time a science subject comes up there are lots of false statements that are very easily contradicts.
I think an honest person will admit that we cannot implement this concept right now. You can only say that maybe in the future it will be possible.
Agreed, an honest person can say that. But an an hoenst person can not say that it's impossible because of "physics" or for that matter that it's impossible because of economics!
I'm not sure why we should take your assessment that they are "very generous estimates" when you started with the false assertion that it's "very clearly non-economical" while pointing to the paper itself as evidence, when the paper refuted you. If you have a complaint, make it, please don't just smear with innuendo, especially since you are reading the paper.
The numbers of $100/kWh, which you talk about as mere speculation, are like forecasting future computing performance and thinking the safe move is to assume no improvement in computing costs.
People that have assumed that storage would stay at the same cost have been proven wrong year after year after year. Suggesting that somehow, just now, prices will stop decreasing, is wild speculation with no basis in fact and should be dismissed out of hand, unless the claimant can at least bother to come up with some resin for the change.
A low end panamax container ship would require fifty-six million, nine hundred twenty-five thousand KwH of energy (56925 mwh).
Academics and beancounters tend to miss out critical factors in how things get done in practice, not in theory.
“Farming looks mighty easy when your plow is a pencil and you're a thousand miles from the corn field.” – Dwight D. Eisenhower
What does your number have to do with the practicality of the prospects of electric container ships? You threw out a number, now justify what you think that means. A big number is supposed to do what?
What battery technology exists today that could even begin to store and deliver the amount of energy needed reliably, how long would they take to charge up? I suspect the size of the batteries would look like a fully loaded container ship.
This isn't 'anti scientific' it's a common sense practical rebuttal of a pseudo scientific/academic fantasy world
There is nothing more anti-scientific than that. You are not even making a basic effort to understand what you are criticizing.
....We assume an ICE tank-to-wake efficiency of 50% and electric motor and inverter efficiencies of 95% each28. Batteries yield an 80% efficiency improvement compared to their ICE counterparts, which translates to a 30% decrease in total energy needs for the battery-electric ship….We assume a containership carries enough fuel for a day’s voyage; in reality, this figure is probably higher, because ships often carry fuel for several days after bunkering…
Most of the initial asssumptions are way off and rely on the 'tightening regulatory landscape' to make hte battery powered fantasy more convincing.
Discuss this with anyone in shipping and they will just laugh
Simply saying "Batteries are really heavy and will be exhausted of power very quickly by the continuous load from underwater propellor propulsion." when those specific points have been discussed in the article does not contribute anything to the discussions and simply makes it appear as if you did not read the article.
The overall takeaway for me is that we need a 10x improvement in battery density, electricity costs to be 1/3 of today, plus a 30x reduction in battery costs, for this to be feasible. At that point, it is 'just' a capex problem to replace the fleet. These are still 'decades away' numbers IMO.
OK. Well the large scale BES plants struggle to get costs below $200 per kWh. So that means that the cost for this battery is about $11,385,000,000. And this doesnt take into account the amount of space and weight this would take up on the ship. The cost of a panamax class appear to be about $300m. or about 38x increase in cost. This seems like a pretty clear case of it's not going to work.
Figure 3 from the article specifically looks at the relationship between battery cost and density vs voyage length on the cost effectiveness of switching.
The article is analyzing balancing lifetime costs of the batteries and their recharging vs. the lifetime costs of fuel for an ICE powered ship.
Does that sound like a cheap tank of gas ?
Yet again, stating a single big number with emphasis is no way to convince anybody of anything. What's the baseline? Or are people just supposed to be scared of big numbers and run away? This is yet again a highly unscientific way to think about a matter.
https://www.morethanshipping.com/fuel-costs-ocean-shipping/
So 38x more expensive to build and 5x more expensive to fuel. And the big hitch with that is getting a power supply large enough to charge a ship in a couple of day turn around.
The entire peer reviewed article is about how to make this calculation and what figures to use as inputs. Instead of discussing the article, you are throwing around numbers you poorly calculated or pulled from random out of date articles you googled.
Are you saying you think that the price of fuel has dropped in the 4 years ? Because looking at the oil market that seems unlikely.
No argument on the pollution item. I'm not anti-electrification in general and yes I had read the article. I just think we should be looking at low hanging fruit. Airlines and large ships are going to be the hardest/most expensive to convert.
My questions may be blunt, but they are necessary to understand what point is trying to be made.
And your big numbers are all addressed in the article we are talking about. It should not be so much work to get people talk about these matters in frank and honest terms instead of allusions and vibes.
Correct me if I'm wrong (skimming some sources and fermi estimating as I can't find it stated), but such a ship can spend about a month at sea at regular steaming speed and cover about 30,000km.
It's fairly widely acknowledged that batteries are getting cheaper. If we started designing a ship now, we could plan to fill it with $50/kWh batteries and investors would not balk. Then we could cut range by an order of magnitude and still serve some routes.
This takes the batteries down to roughly the cost of the ship. Slow steaming or considering more optimistic projections about sodium batteries might even halve it again. Will it compete with bunker oil for a round the world trip? No. Is it worth starting to think about? Totally.
For example the ampere was ordered in 2011
https://en.m.wikipedia.org/wiki/MV_Ampere
Here's a ferry making locals news (use Google translate) which can operate for 3/4 of the day using batteries and has hybrid propulsion to optimally manage the level of charge. So no need for charging at each turnaround.
https://www.sjofartstidningen.se/goteborgs-nya-elfarja-dopt/
Here's a conversion from diesel to electric for a larger ferry on a short route.
https://en.m.wikipedia.org/wiki/MF_Tycho_Brahe
As the systems become more efficient and batteries drop in price more maritime use cases will be enabled. It's simply all about how long between each time you can charge, and which speed you operate at.
FTA:
> Past work has suggested that battery electrification of marine vessels is unfavourable given the low energy density of batteries relative to hydrocarbon fuels28,29,30,31. However, their assumptions about battery energy density and cost are outdated, differing in some cases by one to two orders of magnitude from today’s best-available figures of 210 Wh kg−1 specific energy32 and US$100–134 kWh−1 (ref. 33). Furthermore, these studies assumed that the maximum battery capacity is limited by the existing onboard space dedicated to mechanical propulsion systems and fuel storage, so their findings suggest that battery-electric ships would require several recharges to traverse even short routes.
> For example, for a 5,000 km range small neo-Panamax ship, we estimate that a 5 GWh battery with lithium iron phosphate (LFP) chemistry, with a specific energy of 260 Wh kg−1 (ref. 34), will weigh 20,000 t and increase the draught by 1 m—a small fraction of the ship’s total height and well within the bounds of the vessel’s Scantling (maximum) draught. For voyages longer than 5,000 km, the increase in draught exceeds the vessel’s Scantling draught.
> We find that minimal carrying capacity must be repurposed to house the battery system for most ship size classes and along short to medium-length routes. For a small neo-Panamax containership, representing an average containership in the global fleet, the volume required by the battery system is less than the volume currently dedicated to the ICE and fuel tanks for routes under 3,000 km. For the longest modelled route of 20,000 km for this ship class, the battery would occupy 2,500 twenty-foot equivalent unit (TEU) slots or 32% of the ship’s carrying capacity. Supplementary Table 1 provides the baseline values used for each ship class.
> In the baseline scenario, the TCP of a battery-electric ship is lower than that of the incumbent ICE vessel only for ship classes larger than 8,000 TEUs over voyages of less than 1,000 km (refs. 5,40,47,49,50). Over longer voyages, the additional cost of the battery system, increased power requirements and charging infrastructure outweighs the savings from fuel switching and the efficiency gains of direct electrification. However, if the environmental costs of NOx, SO2 and CO2 are considered, the cost-effective range increases to 5,000 km across all size classes given the high emissions rates of HFO relative to the emissions intensity of the US grid.
Again, the article goes into all of this. If you want to discuss this productively, you need to read the article and criticism where their assumptions, model, or calculations are flawed.
> For example, for a 5,000 km range small neo-Panamax ship, we estimate that a 5 GWh battery with lithium iron phosphate (LFP) chemistry, with a specific energy of 260 Wh kg−1 (ref. 34), will weigh 20,000 t [...].
Even then, a ship with 5000 km range is only useful in very limited circumstances. 3000 km range is almost useless.
> The sector’s trend towards containership gigantism has promoted a hub-and-spoke model of trade, whereby high-capacity mega-containerships transport goods over long distances from one hub to another54. From the destination hub, a host of smaller feeder ships transport the containers to their final destinations in smaller regional ports. Nearly all of these feeder ships traverse short routes that could be electrified, which would increase battery-electric containership adoption well beyond the potential suggested by intraregional trade figures. Figure 5 depicts the ten best-connected ports in the world, all of which are intraregional routes less than 5,000 km in length2. Moreover, feeder ships are older on average than their larger-capacity counterparts, and many are reaching the end of their useful service lives56. The 2020 IMO regulation limiting sulfur content will probably lead to the premature scrapping of these fuel-inefficient ships, creating an opportunity for battery-electric models to enter the fleet57.
> Although containerships, with their standardized cargo and volume dependency, are useful for understanding the technoeconomics of battery-electric shipping, they represent only 23% of total maritime shipping emissions58. Achieving larger emissions reductions will require electrifying additional ship types, including oil tankers, bulk carriers, general cargo ships and cruise liners. Of those, bulk carriers and oil tankers seem to have the largest emission footprint. Unlike containerships, some of these ship types are primarily constrained by weight rather than volume41. Energy density by weight is therefore the critical technical parameter for the batteries that would power these ships.