General > General Technical Chat
the dark side of cobalt
tom66:
No, let's go there because this keeps getting brought up and it needs to be put down as a myth. You don't have to be a zealot to be disappointed by people misrepresenting the situation. Hydrogen is the new oil...? Okay... it's not an energy source so I'm not sure what you're going with there, you still need electricity or natural gas to make it. It's a rather inefficient way to store energy, it has some interesting use cases where batteries can't compete on power/energy density but it's really not that interesting outside of those areas. Seasonal energy storage is definitely an interesting use case - but use the electricity produced to charge cars!
--- Quote from: AVGresponding on July 11, 2023, 05:37:31 am ---Please demonstrate the maths for this claim. I work for a local authority as a sparks and I have some knowledge of the difficulties we're facing in our plan to change the fleet to full EV; our infrastructure alone will require a very large (>£100m) capital investment to be able to handle this, and that's for just a few hundred vehicles.
--- End quote ---
Average EV efficiency = ~3.5 miles per kWh (e.g. VW ID.3, Hyundai Kona, Tesla Model 3 size car)
Average UK driver = 6800 miles per year [1]
Average energy consumption per car per year = 9000 / 3.5 = ~2570kWh + 10% for charging losses so call it 2800kWh
Number of cars on UK roads = 33 million [2]
Total annual energy consumption for cars = 2800kWh * 33 million = 93.2 TWh
Annual UK electricity production = 333TWh [3]
Proportion is therefore 27.8%. A little higher than I remembered, I quoted 15-20%, but let's call it within the margin of napkin math. Average mileage has been falling precipitously over the last two decades so it may well end up closer to 20%.
As for the cost to your local authority, the cost of local infrastructure upgrades is not the same as overall generation capacity; there's no doubt that we'll need to increase capacity there e.g. for rapid chargers or businesses/LAs needing to charge their fleet every night. But, that being said for passenger cars (which is my figure), a car doing 6,800 miles per year would need to charge for only about 4 hours per week. With smart charging, and cars spending most of their time parked up somewhere, it's possible to distribute loads in areas where there are capacity constraints. Look into Octopus Intelligent for an energy company experimenting with this at an early stage, dispatching cars as load for wind turbine overproduction for instance.
[1] https://www.nimblefins.co.uk/cheap-car-insurance/average-car-mileage-uk
[2] https://www.racfoundation.org/motoring-faqs/mobility#a1
[3] https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1094628/DUKES_2022_Chapter_5.pdf
nctnico:
Again, stop digging your own grave. There are numerous reports out there (easely found by Google) that have calculated that hydrogen infrastructure for mass use by cars is cheaper. And many of these reports seem to base their price comparison on charging your EV from your own socket instead of (more expensive) public charging. And again, if you start out from efficiency, then your calculation is wrong right off the bat. The only thing that counts are costs per distance travelled.
Also the notion to use cars as grid storage is flawed. First of all batteries are way too expensive (also due to needing lots of materials, including those which are harmfull for the environment to mine) for storing electricity for more than a half a day. Let alone seasonal storage which is what is needed. Secondly using a car's battery as storage means using a battery in a way that it hasn't been designed for and you'll be wearing the most expensive part of the car without getting the monetary value for that wear. The idea is similary stupid as using solar roadways to heat roads in the winter. The power companies love it though because it means a free lunch. No, it is making money with a lunch on top for them.
PlainName:
--- Quote from: nctnico ---There are numerous reports out there (easely found by Google) that have calculated that hydrogen infrastructure for mass use by cars is cheaper
--- End quote ---
I'm not in either camp (happy with my petropolluter) but it seems to me that EV is the sensible way even if it costs more. Reason being that it's flexible: with hydrogen or petrol or fermented poo or whatever the infrastructure necessary is tied to the product. Sure, you can convert petrol garages to hydrogen, but it costs and takes forever (relatively speaking). On the other hand, with EV you can use ALL those products to produce the electricity in a few central places, and even combine mixed producers. The major infrastructure won't change depending on source.
Obvious advantage: if we were already EV-based and burning oil to get the electricity, the switch to solar and wind power would have zero effect on any car or the way they are charged or the way that charge is delivered. So hydrogen may be the next best thing, but it should be in deriving the electricity for EVs, not creating work to replace infrastructure that will itself be replaced when the next best thing comes along.
Siwastaja:
--- Quote from: tom66 on July 11, 2023, 08:32:41 am ---No, let's go there because this keeps getting brought up and it needs to be put down as a myth.
--- End quote ---
That will simply never happen. People with non-engineer mindsets will never understand this, even if it's totally obvious to anyone who has ever worked on the numbers or made observations of the reality around us. This hydrogen car revolution was supposed to happen numerous times already and the fact it never happens, exactly as predicted by physics and engineering, does not change the belief of those who want to believe.
It's exactly the same as with solar roadways. It's all demonstrable and doable, but doesn't make any practical sense. People like nctnico love these kinds of projects.
nctnico:
And yet extra hydrogen fueling infrastructure is being rolled out further every year. That is my real world observation. Another real world observation is that many car manufacturers have hydrogen cars ready for production in large numbers. That kind of puts a pin in 'it is obvious it will never happen'. If hydrogen is an obvious non-starter then why are companies investing billions into cars on hydrogen. Better apply for a job as CEO there, you'd save them lots of money. In the real world: cars on hydrogen take longer to arrive as the hydrogen needs to be sourced renewable, but it will get there. Likely at the end of this decade.
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