gasoline v hydrogen

[tjh290633]

It's been said that its expensive to produce hydrogen (and we'll just focus on green hydrogen here). But it must be quite expensive to produce a gallon of gasoline from absolute scratch. Prospecting, drilling extraction, transportation, refining and so on.

I've been trying to find a reasonable comparison without much success. Obviously it depends on where the crude oil is extracted but given hydrogen is just water and electricity and (more or less) can be made on site then they cant be that far apart. Can they?

Cheers

Is hydrogen produced by a nuclear reactor classed as green btw?

If you produce hydrogen by electrolysis, then you use electricity. Since that comes via the grid, you have no control over where the actual electrons used come from. That could be coal fired, hydroelectric, nuclear, wind, tidal or a man pedalling a bicycle.

For barrage balloons, the hydrogen was produced by the steam-iron process, in which the steam was reduced to hydrogen by reacting with iron. It needed a blow cycle, as I recall, to raise the temperature of the iron. That might have used producer gas.

Regarding the production cost of crude oil, in some places it just bubbles to the surface, but elsewhere you have to drill and pump. Each well has an economical price below which it is not worth extracting the oil. That price has a wide range, from a few dollars to $50 or more. When the oil price fell, a lot of shale deposits became uneconomical to operate.

TJH

[AWOL]

Not the same question but i have read that it was shown long ago that hydrogen fuel cell vehicles cost three to four times as much energy to power a car as running it off batteries. Regardless of how it is generated that is a lot of energy. Hydrogen is more an energy store than source. The question is how does it compare with alternatives. I need to look at iron as an energy store.

[scrumpyjack]

I thought the intention was that hydrogen would be produced from Wind farm energy whenever that electricity was not required by the grid (and currently owners are paid not to supply it to the grid), in which case the surplus electricity in effect costs nothing.

[JohnB]

Better to charge car batteries, produce ammonia, pump water uphill, smelt steel etc etc than produce hydrogen and then burn it. It really is only useful as a power consumer of the last resort

[Hallucigenia]

It's been said that its expensive to produce hydrogen (and we'll just focus on green hydrogen here). But it must be quite expensive to produce a gallon of gasoline from absolute scratch. Prospecting, drilling extraction, transportation, refining and so on.

I might suggest that you would get a more, shall we say,...focussed... reply over on the oil board rather than DAK. But broadly you can say 1 barrel of oil is 159 litres and contains 1.7 MWh of energy, the same as 50kg of hydrogen.

Current prices for green hydrogen are around $3-6/kg, so £125-£250 for 50kg. See eg this recent paper from HMG for the cost of different technologies (but multiply by 1.7!)
https://assets.publishing.service.gov.u ... df#page=31

Whereas production costs for oil are maybe $5/bbl in the Middle East, $50/bbl offshore. Yes you have to transport it to a refinery and refine it, but that costs a couple of bucks.Oil is dirt cheap for what it is.

Eg some 2018 refining costs here : https://www.compassinternational.net/wp ... _Capex.pdf
Their basic little 60,000bpd-capacity refinery in the US costs $762-$918 million. Amortise that over 20 years, allow for some maintenance downtime and it's about $2 per barrel plus say the same again in finance costs.
They estimate opex for a 50,000bpd refinery (ie 17.5 million barrels per year) at $8.9m so another $2/bbl.

So the average barrel of oil products costs about half the cheapest green hydrogen (before you start adding taxes and margin).

The real issue is that the infrastructure for hydrocarbons is already built and (largely) depreciated, whereas for hydrogen you're having to do massive capex before you sell a single kg. Which in turn means that for the next decade it will largely be confined to discrete sites such as chemical plants where it can be used on site without needing lots of transport infrastructure.

And to be honest, hydrogen isn't really competing against "oil" but natural gas - for the next several years the limited amounts of hydrogen available will be sucked up by the likes of chemical and fertiliser plants that don't have alternatives to replace the chemical reactivity of natural gas, whereas eg most forms of transport will have alternatives in the form of batteries. And if your application can use batteries, you see eg 85-90% efficiency from windmill to wheel, whereas going via hydrogen gives you 45-50% efficiency. Unless there's a huge lithium shortage then physics dictates that hydrogen just won't be able to compete with batteries for mainstream transport (outside certain niches).

And the infrastructure argument also applies - we have an electricity grid already. Yes it needs changes to accommodate the coming electrification of heat and transport, but it's an inherently incremental process rather than almost starting from scratch like hydrogen.

Is hydrogen produced by a nuclear reactor classed as green btw?

There's a can of worms, not least because terms like "green hydrogen" have no official status. But eg the EU will consider hydrogen from nuclear as "low carbon hydrogen" for the purposes of their classification (and see herefor what that means in UK terms)

[doug2500]

May be of interest:

https://www.autoexpress.co.uk/bmw/10786 ... powertrain

[GrahamPlatt]

May be of interest:

https://www.autoexpress.co.uk/bmw/10786 ... powertrain

So the tanks contain 6Kg of hydrogen, which (to use hallucigenia’s figures above) would cost circa £36 and contain 1,224 kW of energy.
Sounds pretty good to me.

[Hallucigenia]

May be of interest:

https://www.autoexpress.co.uk/bmw/10786 ... powertrain

So the tanks contain 6Kg of hydrogen, which (to use hallucigenia’s figures above) would cost circa £36 and contain 1,224 kW of energy.
Sounds pretty good to me.

Err - not sure how you get that? 1kg hydrogen contains 33.6 kWh, but you lose say half of that turning it into motion, so effectively 1kg of hydrogen is about 17kWh of kinetic energy. So 6kg corresponds to 201.6kWh of hydrogen energy and about 100kWh of kinetic energy.

When I say it costs $3-6/kg above, that's production cost before profit and tax, in the same way that a litre of petrol costs 6-40p/litre to make. The pump price is rather different...

But at a handwaving level, you're talking about a "tank" of hydrogen costing £15-30 to manufacture, versus £3-20 for a 50l tank of petrol.

[XFool]

Not the same question but i have read that it was shown long ago that hydrogen fuel cell vehicles cost three to four times as much energy to power a car as running it off batteries. Regardless of how it is generated that is a lot of energy. Hydrogen is more an energy store than source.

The only thing I would quibble with is that word "more". Hydrogen isn't a source of energy at all. Surely it's best to compare it to electricity, an energy transporter (OK hydrogen can also be a direct store of energy).

It's never a source of energy - unless fusion reactors can be got to work - as there is no such thing as 'hydrogen wells' *, anymore than there are 'electricity wells'.

BTW. This is not intended as any kind of criticism of hydrogen.

* Excepting hydrogen present as an elemental component of natural gas. But I take it this is a discussion about molecular hydrogen.

[Mike4]

Not the same question but i have read that it was shown long ago that hydrogen fuel cell vehicles cost three to four times as much energy to power a car as running it off batteries. Regardless of how it is generated that is a lot of energy. Hydrogen is more an energy store than source.

The only thing I would quibble with is that word "more". Hydrogen isn't a source of energy at all. Surely it's best to compare it to electricity, an energy transporter (OK hydrogen can also be a direct store of energy).

It's never a source of energy - unless fusion reactors can be got to work - as there is no such thing as 'hydrogen wells', anymore than there are 'electricity wells'.

BTW. This is not intended as any kind of criticism of hydrogen.

Solar panels are partially analogous to electricity wells.

When I lived on my boat the solar provided 100% of my electricity requirements for eight months of the year. It was just like having an electricity well. Certainly the electricity just kept on coming, free of charge and no effort involved.

But you are right hydrogen is not an energy source. It is more analogous to a battery, being a method of storing and transporting energy.

[XFool]

It's been said that its expensive to produce hydrogen (and we'll just focus on green hydrogen here). But it must be quite expensive to produce a gallon of gasoline from absolute scratch. Prospecting, drilling extraction, transportation, refining and so on.

Perhaps this is obvious, but...

I guess the killer 'cost' here is less monetary and more in terms of energy 'costs'. i.e. It 'costs' a certain amount of energy to get a given unit of energy from fossil fuel. The ratio between output energy/input energy determines how 'valuable' fossil fuel is as an energy source. Presumably if/as/when this ratio approaches unity, fossil fuel becomes valueless (as a source of energy, at least).

Why is this bringing Bitcoin to mind?

[XFool]

Hydrogen isn't a source of energy at all. Surely it's best to compare it to electricity, an energy transporter (OK hydrogen can also be a direct store of energy).

It's never a source of energy - unless fusion reactors can be got to work - as there is no such thing as 'hydrogen wells', anymore than there are 'electricity wells'.

Solar panels are partially analogous to electricity wells.

Taking that further...

Solar panels are 'electric energy wells' mining present day solar (fusion) energy. Fossil fuels are energy wells mining millions of years of prehistoric solar (fusion) energy - which leads to well publicised (but still seemingly 'controversial' !) issues.

[spasmodicus]

Solar panels are 'electric energy wells' mining present day solar (fusion) energy. Fossil fuels are energy wells mining millions of years of prehistoric solar (fusion) energy - which leads to well publicised (but still seemingly 'controversial' !) issues.

Yeah, so you cough up thousands of quid to install a solar array, the bigger the better. Then you find that your heaviest power requirements are at night, when the panels don't work. So you either have to install battery storage (expensive and complicated) or use gas or electricity from the grid to heat and illuminate your home and sell your excess power to the grid during the day. Hydrogen aficionados will assert that this power can then be used to generate hydrogen by electrolysis. Trouble is, your friendly power supplier (e.g. Octopus) will only give you a measly 4.7p per kWh whilst charging you 53.04p/kWh in the daytime or 36.61p /kWh at night ( Eco 7 tarriff) for power that you take from them. To add insult to injury, there is a standing charge of 43.22p/day. If you use gas, they will charge you 15.67p/kWh (27p a day standing charge). Converting your fed-in PV power (25% or so conversion of incident energy to electricity) to hydrogen (max energy efficiency 70%) and then selling it back to you through the (leaky) gas grid so that you can burn it in you boiler (effciency 90% if you're lucky) seems completely bonkers. It's no wonder that our scientifically illiterate politicians can only flounder about and wave their arms in the air.

Also, If the above isn't daylight robbery, then I don't know what is. The horrendous inefficiencies and ridiculous tariffs demonstrate just how screwed up the whole energy business is in the UK. It's cheaper and better to use your excess PV power to run your hot water immersion heater. Of course, hydrogen's role in all this is to make it all appear green.

this one will run and run,
S