Will Electric Vehicles Be Viable? When?

[izzy]

my Wiki says microturbines are 25 - 500 kW and 15% efficient without a (bulky, heavy) recuperator

the 'principles' of disadvantage seem to be rather strongly proclaimed ...
tip losses and the boundary layer losses are disproportionately large with small size - and short length is a hindrance
ie these don't downsize

and remember the F1 turbine has the 'free power' of exhaust pulse blowdown

so if they have a 600kW one they can't call it a microturbine? omg they'd have to call it something else . they could use multiple stage, and a recuperator is just a heat exchanger, how much would it weigh? as for boundary layer, that's a bit of a red flag on a forum tbh, with no numbers or sources, and 'tip losses' is a bit in the same bracket

and obviously it all does downsize as we're not even talking about small ones, but ones that are actually too big!!

anyway i just think they'd be extremely cool to have on an F1 car, and whatever efficiency they have now would rocket with F1 getting involved, as long as FIA didn't strangle it with limits

[roon]

Tip losses should scale if a similar gap:rotor-diameter ratio can be maintained.

Hydrogen is interesting. BMW made a clever hydro V12 a few years back. Hydrogen combustion exhaust components relatively pleasant. If you traditionalists must, include some carbon sources in the mix--we can condense and recollect some fizzy water in the exhaust for use in the podium proceedings... ~sUstAiNaBiLiTy~

[Big Tea]

Rather than a turbine generator, would it not be good to use a small Wankel engine?
Light weight, small, and if running constantly at an efficient speed low (compared to its roadgoing self) polluting.
It could possibly be 'stacked' to run the second rotor just with the exhaust from the first using expansion (would there be enough to re burn?) Easier to silence than a turbine too.

An additional advantage over road going would be ease of removal for refit as it would not need alignment to the transmission etc.

[roon]

If space is a primary concern then a rotary Otto or turbine would be investigated, although recuperator size may ultimately disadvantage the turbine in that specific context. I'm not sure if wankel type rotary engines will ever be as maintenance free as piston type reciprocating engines with poppet valves. For a range extender: requirements I would guess should be more along the lines of: extended run time with extreme duration oil change intervals.

[izzy]

Rather than a turbine generator, would it not be good to use a small Wankel engine?
Light weight, small, and if running constantly at an efficient speed low (compared to its roadgoing self) polluting.
It could possibly be 'stacked' to run the second rotor just with the exhaust from the first using expansion (would there be enough to re burn?) Easier to silence than a turbine too.

An additional advantage over road going would be ease of removal for refit as it would not need alignment to the transmission etc.

it would be fun to let teams do whatever they wanted for a charger, just limit the input rate to the battery.

and while we're at it, take off the minimum weights as well.

[Brake Horse Power]

Hydrogen has its own problems with storage and explosivity. Oh, and you have to produce it too.

Petrol needs to be produced as well? The challenges you mentioned have been solved.

Toyota produces the Mirai car, Hyundai the Nexo and also other brands will come. Nikola a US truck OEM startup will produces a lot of H2 trucks. In all ways competitive or better than the diesel equivalent. Also safer because of redundant drive and brake systems. Amazon has their warehouse forklift fleet on Hydrogen etc.

So why not continue this way? In all cases the hydrogen is produced and apparently it is safe..

[Just_a_fan]

Hydrogen has its own problems with storage and explosivity. Oh, and you have to produce it too.

Petrol needs to be produced as well? The challenges you mentioned have been solved.

Well, it's solved in the same way that petrol safety is solved. Petrol fires still happen and I'd much rather tackle a petrol fire than a hydrogen one. If the hydrogen one goes wrong, it's a bomb waiting to happen.

Hydrogen production, amusingly, also produces lots of CO2 ("Depending on the quality of the feedstock (natural gas, rich gases, naphtha, etc.), one ton of hydrogen produced will also produce 9 to 12 tons of CO2." ##). That's funny as people suggest it as a solution to the CO2 issue. Of course, CO2 sequestration could be done at the H2 production facilities but, well, it isn't. So H2 fuel is no better than petrol really - indeed about 3 times worse.


## https://www.aidic.it/CISAP4/webpapers/7Collodi.pdf

[Just_a_fan]

Hydrogen combustion exhaust components relatively pleasant.

In an ideal world, just water but, of course, it's not an ideal world and no doubt NOx etc are also produced. Plus hydrogen production is a big source of CO2. Which is ironic.

[Andres125sx]

Hydrogen has its own problems with storage and explosivity. Oh, and you have to produce it too.

Petrol needs to be produced as well? The challenges you mentioned have been solved.

Well, it's solved in the same way that petrol safety is solved. Petrol fires still happen and I'd much rather tackle a petrol fire than a hydrogen one. If the hydrogen one goes wrong, it's a bomb waiting to happen.

Hydrogen production, amusingly, also produces lots of CO2 ("Depending on the quality of the feedstock (natural gas, rich gases, naphtha, etc.), one ton of hydrogen produced will also produce 9 to 12 tons of CO2." ##). That's funny as people suggest it as a solution to the CO2 issue. Of course, CO2 sequestration could be done at the H2 production facilities but, well, it isn't. So H2 fuel is no better than petrol really - indeed about 3 times worse.


## https://www.aidic.it/CISAP4/webpapers/7Collodi.pdf

Sorry but that´s a big nope. Petrol does not produce only CO2, it´s producing a lot of harmful substances like CO, NOx, cancerous microparticles...

That´s something wich drive me nuts frequently, when people talk about pollution, many of them assume they´re only talking about CO2, but there are thousands deaths every year because of pollution, and CO2 has same responsibility in those as my cat.

Petrol does produces many many harmfull substances, both for the environement causing global warming, and for any living organism causing respiratory diseases and even cancer, so stating H2 is worse than petrol because it does produce more CO2 sorry but is flawed at minimum

[Brake Horse Power]

Hydrogen has its own problems with storage and explosivity. Oh, and you have to produce it too.

Petrol needs to be produced as well? The challenges you mentioned have been solved.

Well, it's solved in the same way that petrol safety is solved. Petrol fires still happen and I'd much rather tackle a petrol fire than a hydrogen one. If the hydrogen one goes wrong, it's a bomb waiting to happen.

Hydrogen production, amusingly, also produces lots of CO2 ("Depending on the quality of the feedstock (natural gas, rich gases, naphtha, etc.), one ton of hydrogen produced will also produce 9 to 12 tons of CO2." ##). That's funny as people suggest it as a solution to the CO2 issue. Of course, CO2 sequestration could be done at the H2 production facilities but, well, it isn't. So H2 fuel is no better than petrol really - indeed about 3 times worse.


## https://www.aidic.it/CISAP4/webpapers/7Collodi.pdf

On the tanks are safety valves mounted which also activate above a certain temperature. So the tanks will release the hydrogen. If the hydrogen does not catch fire it will quickly dissipate in the atmosphere. If it does catch fire you will have a colorless flame which burns until the tank is empty. The only reasonable way it can explode is when it vents and the gas accumulates under a ceiling or in a convinced space.

The hydrogen can be produced by elektrolyses , which is zero emission..

[Just_a_fan]

so stating H2 is worse than petrol because it does produce more CO2 sorry but is flawed at minimum

I was stating that it produces more CO2, that's it. I wasn't really talking about other pollutants, although hydrogen only burns cleanly in ideal conditions. In less than ideal conditions, the heat will still cause NOx to be produced because the hydrogen is being burned in air, not oxygen. So let's not claim that hydrogen is the "clean fuel" because it isn't.

[Just_a_fan]

On the tanks are safety valves mounted which also activate above a certain temperature. So the tanks will release the hydrogen. If the hydrogen does not catch fire it will quickly dissipate in the atmosphere. If it does catch fire you will have a colorless flame which burns until the tank is empty. The only reasonable way it can explode is when it vents and the gas accumulates under a ceiling or in a convinced space.

The hydrogen can be produced by elektrolyses , which is zero emission..

A leak in to an enclosed space, such as a car's luggage space, for example? The average car's luggage space would make for a nasty explosion if the worst happened.

Hydrogen can be produced by electrolysis, but the vast majority (c.95% I think) is from steam reforming which is energy intensive and results in CO2.

If we're going to install sufficient renewable capacity to allow generation of sufficient hydrogen for vehicle fuel, we might as well just miss out the middle man and use the electricity directly. Oh, and we're unlikely ever to install sufficient renewable capacity to do that, either via hydrogen or direct use. The UK currently generates about 20% of its electricity demand from renewable sources. Almost all (>99%) of that electricity goes to heating, lighting, industry. Transport is almost entirely oil powered (petrol, diesel).

Of course, we could do it, but there isn't the political will, nor the finance available, to make the UK fully renewable-resource powered - whether that's direct electricity or via hydrogen as storage.

[santos]

The UK currently generates about 20% of its electricity demand from renewable sources.

That's pretty low for a country like UK. And you can do much more than that. More of 50% of the energy consumed in Portugal its from renewable sources.

[izzy]

The UK currently generates about 20% of its electricity demand from renewable sources.

That's pretty low for a country like UK. And you can do much more than that. More of 50% of the energy consumed in Portugal its from renewable sources.

According to https://smarterbusiness.co.uk/uk-renewa ... tage-2018/ the UK is on 37.4% atm

and one of the best things about an EV car is that you can charge it at night or from your own solar panel or wind turbine so it's not using any extra fossil fuel at all

[Just_a_fan]

According to https://smarterbusiness.co.uk/uk-renewa ... tage-2018/ the UK is on 37.4% atm

and one of the best things about an EV car is that you can charge it at night or from your own solar panel or wind turbine so it's not using any extra fossil fuel at all

Live data suggests otherwise: http://gridwatch.co.uk/ . Was at 19.7% when I made my earlier post, now at 21.79%. It's a sunny day in the UK, generally, so the solar panels are doing well at the moment, but are at basically the same level as nuclear (13-14% of generation). That's the difference between installed capacity (I'm guessing that's the 37.4% you mentioned) and actual generation. And bear in mind that almost all of that generated electricity is going to the non-transport sectors. If you want to make the UK totally regen-resourced, then you need to be able to replace all of the current generation plus provide a massive amount more for transport. And upgrade the grid.

You can charge your car from your own solar panels - if you park at home during the day or have a very large battery stack in your garage to store the energy. Would you get enough in winter to be totally off-grid for recharging the car?

I'd be amazed if a domestic wind turbine would get anywhere near to charging a car for most people in an urban environment, unless it's again going via a large battery stack and you don't need to fully recharge the car every day.

Most people are going to be using grid-sourced energy at some point to charge cars, especially when using charging spaces away from home e.g. municipal car parks.

I'd love to think that the UK could be 100% renewable for all of our needs - not least as it would give total energy security - but it's a pipe dream, sadly.