D5 / Diesels: A moral question on emissions and alternatives

[vzh7gk]

With majority of trips still under 3 miles and a catalytic convertor taking 3+ miles to reach full working temperature, there's an awful lot of pollution from petrol engines too...
Just my 2d...

[Joe of Loath]

Originally Posted by canis

The environmental solution is to continue using the car until the end of it's natural life. Otherwise you've got the environmental costs of building the thing in the first place, and the env. costs of dismantling/recycling a working vehicle, all on your conciounce.

The perfect solution is hydrogen. Hydrogen produced by electrolysis in equatorial desert regions boosting 3rd world economies, saving farmland for food production in temperate zones instead of these wretched bio-fuels.

Alas, the world makes strange decisions. We've got deserts doing nothing, solar panels on britsh houses (seriously, wtf?), charging electric cars in the name of environmentalism, and as everybody with a solar-powered garden ornament knows - the batteries don't last.

The problem (apart from economics) is the storage and carriage of potential energy from source to use. Hydrogen solves this, and these new high compression electrolysis machines look very promissing.

As a species, we really need to get our sh1t together.

Hydrogen isn't a magic bullet though. For a start most hydrogen is currently produced by cracking hydrocarbons, which is no use to anybody other than that it's cheaper than electrolysis of water.

Second is efficiency. Why generate electricity (generation and transmission is maybe 30% efficient at best), perform electrolysis (30% efficiency? 50 if you're lucky?), transport it*, and convert it back into electricity (40-60% efficiency) when you could just use the electricity to charge batteries?

*transportation is a huge problem, because hydrogen atoms seep through pretty much anything and you lose pressure. Plus you're carrying round huge tanks of one of the most explosive gasses on earth (one that will combust at virtually any oxygen concentration). You can't use most metals due to hydrogen embrittlement, so you have to find some kind of composite to use instead.

Lithium batteries seem to be lasting about 10 years in most electric vehicles nowadays (there are still original Tesla Roadsters out there driving round at >80% capacity), and the contents are almost 100% recyclable. Mash up the battery in an industrial shredder and separate out the components and you can make a new battery - we already do this with lead acid batteries, which are virtually a closed cycle manufacturing process.

This isn't mobile phones (because I know someone will make that point), where the batteries are used to an inch of their life for ten minutes extra battery life to put on the marketing materials. In a car they're very carefully managed for better lifespan.

And yes, solar panels do work in the UK. Just because there's a few clouds, doesn't mean the solar panel stops working completely, you'll still get a good percentage of total output.

[TDIvolvo]

Originally Posted by BritInSweden

I love my 2005 V70 D5, more than is probably healthy, but every day I am being persuaded more to scrap her or at least the engine.

The issue is emissions. Which is wideley discussed on here but I wanted to get an updated take on it as news keeps pouring in how bad diesels are and it's not going to get any better.

I live in Sweden. Road tax for my soot belching Euro 3 is £700 per year. I drive 7000 miles per year. I have small kids who breathe in that soot and so do other folks in the world. So financially and morally i feel i should say goodbye to what is the best most reliable car i ever owned.

But I love the car! Everything about it except the engine emissions. So what are the options?

Do you think it will be feasible / practical that retrofit ad blue / SCR or equivalent technology is going to save us and the world as it is with commercial vehicles now?

Should i consider swapping the engine to an lpg, bio fuel? Any guesses how much it might cost? Or indeed worth it?

Or keep the D5 for parts and shell out £4000 odd for a more environmentally friendly v70 which I probably can't afford. Guess this is the bifuel v70. Are they any good?

Any help appreciated as to are partners to fund a cheap retrofit SCR kit that's going to make us and the world much richer 😃

Thanks in advance!

My thoughts are that you only drive 7000 miles a year and your D5 is fairly clean (compared to some diesels), so your not exactly belching out tonnes of soot. If you can bear the tax then keep it. Other option is look for a petrol one. I must admit I was always a diesel fan, always thought I would only ever get diesels but I am a convert.

If you are concerned you could use synthetic diesel - a bit more pricey but the emissions are much less as it's actually fuel synthesised from gas.

[canis]

Originally Posted by Joe of Loath

Hydrogen isn't a magic bullet though. For a start most hydrogen is currently produced by cracking hydrocarbons, which is no use to anybody other than that it's cheaper than electrolysis of water.

Second is efficiency. Why generate electricity (generation and transmission is maybe 30% efficient at best), perform electrolysis (30% efficiency? 50 if you're lucky?), transport it*, and convert it back into electricity (40-60% efficiency) when you could just use the electricity to charge batteries?

*transportation is a huge problem, because hydrogen atoms seep through pretty much anything and you lose pressure. Plus you're carrying round huge tanks of one of the most explosive gasses on earth (one that will combust at virtually any oxygen concentration). You can't use most metals due to hydrogen embrittlement, so you have to find some kind of composite to use instead.

Lithium batteries seem to be lasting about 10 years in most electric vehicles nowadays (there are still original Tesla Roadsters out there driving round at >80% capacity), and the contents are almost 100% recyclable. Mash up the battery in an industrial shredder and separate out the components and you can make a new battery - we already do this with lead acid batteries, which are virtually a closed cycle manufacturing process.

This isn't mobile phones (because I know someone will make that point), where the batteries are used to an inch of their life for ten minutes extra battery life to put on the marketing materials. In a car they're very carefully managed for better lifespan.

And yes, solar panels do work in the UK. Just because there's a few clouds, doesn't mean the solar panel stops working completely, you'll still get a good percentage of total output.

Thanks for one of the most well reasoned posts on the whole forum. Admitedly, I'm a fairly new convert to the hydrogen idea, and these are all challenges which need to be overcome.

You're right that hydrogen is currently manufactured out of other gases, Helium I think, because it's cheaper. But it's not cheaper environmentally, and we are (or we ought to be) looking for an environmental solution. Imagine if cars were free. What a world that would be! Okay, I'm dreaming, but what would Nik Tesla be doing if he was faced with this situation?

It's also true that solar panels can produce useful power in Britain. But it's unquestionable that they would produce far more closer to the equator. I think it would make sense to uproot them all from here and transplant them in useless, but sunny, areas. The difficulty is; How do you get the power from there to here? Hydrogen is merely a means of storing that energy. Who cares if it's not very efficient? With that much sunshine available (currently wasted on desert sands) anything greater than zero can be considered free energy. It will be still more efficient than whatever can be obtained here, so far north. It's not simply the weather, either. Being so close to the Tropic of Cancer, sunlight which reaches a solar panel here innevitably is 'stretched' over a greater surface, due to the angle of it's arrival. Closer to the equator, the sunlight arrives at the panel "head on", perpendicular to the ground. Not just more output, but vastly more output!

Storage is an issue. Of course storage is an issue, the same is true of petroleum, crude oil, even natural gas. There has been enormous investment into the production of petroleum products. I don't know how much an oil tanker costs, but I would guess a tanker for the carriage of hydrogen gas wouldn't be much more expensive.

These technologies already exist. This is why the search for water on The Moon and Mars is so important. It's not simply to quench astronauts thirst. It's because it can be turned into oxygen (kinda important to humans) and hydrogen as a useful propellant. And sunlight is very cheap.

But I wonder, is there enough Lithium in the world to make enough batteries for everybody to have a car? And how much energy does it take to charge one? As a percentage of what you get out of it? Last I heard (but I'm willing to be corrected) it was about 8-1. What's that, 12%, maybe? Right here in this forum there are people wondering why they cannot achieve the service life they expected from batteries alone. They are using them to depletion, until forced to employ the combustion engine to supplement.

I'm not opposed to electric cars. I've not driven one, but I have driven a milk float and the accelleration is quite different. Magnetism is a wonderful thing for moving things around, and the pull of an electric motor is quite phenomenal. I have no doubt Tesla owners are very satisfied, even though I've not actually driven one myself. I like the idea of hybrid engines very much, regenerative braking, electric power from standstill (arguably when a combustion engine is at it's least efficient), these are all good ideas.

I'm just not convinced by the British solar panel thing. I'm forever hearing people say how well they work, and what a saving on their bills it is, but that's because the government is paying insane amounts of money per kilowatt/hour. Nobody in their right mind would buy electricity at those prices, it's no wonder the owners of these things are saving money on their bills. It's a fake resource.

I'm interested to know more about Hydrogen leaking through most materials though. Where can I read about this? I wasn't taught chemistry at school.

[Joe of Loath]

Originally Posted by canis

Storage is an issue. Of course storage is an issue, the same is true of petroleum, crude oil, even natural gas. There has been enormous investment into the production of petroleum products. I don't know how much an oil tanker costs, but I would guess a tanker for the carriage of hydrogen gas wouldn't be much more expensive.

Unfortunately it's a much bigger problem than petroleum due to the aforementioned hydrogen embrittlement. It's a big field of scientific research, see how many proposed technologies there are: https://en.wikipedia.org/wiki/Hydrogen_storage. Most vehicles use something like carbon fibre, but that's still not a perfect solution.

But I wonder, is there enough Lithium in the world to make enough batteries for everybody to have a car? And how much energy does it take to charge one? As a percentage of what you get out of it? Last I heard (but I'm willing to be corrected) it was about 8-1. What's that, 12%, maybe? Right here in this forum there are people wondering why they cannot achieve the service life they expected from batteries alone. They are using them to depletion, until forced to employ the combustion engine to supplement.

More than enough. Hell, you can extract it from seawater if you want, but there's actually not much lithium by weight - it's mostly carbon and organic electrolyte.

And unfortunately you heard wrong. Lithium ion charge and discharge efficiency is somewhere in the 80-90% range. You can test it by feeling big RC car or drone batteries during charge and after discharge - they're barely warm to the touch, even after palm sized batteries discharging at tens of amps. With >90% efficient brushless motors, electricity is *really* efficient. Makes you wonder why we're messing around with 20% efficient ICE tech...

I'm just not convinced by the British solar panel thing. I'm forever hearing people say how well they work, and what a saving on their bills it is, but that's because the government is paying insane amounts of money per kilowatt/hour. Nobody in their right mind would buy electricity at those prices, it's no wonder the owners of these things are saving money on their bills. It's a fake resource.

I can't comment on it from a household standpoint, but my dad has an 80 watt solar panel on the roof of his camper van, and it's enough to keep the leisure battery charged for use with lights, phone chargers, and to power the coil in the diesel heater. Even on an overcast day he'll see about 1A from the panel, which is about 1/6 the total output. A very sunny winter day might give 4A.

At university we performed experiments with solar panels and filters to simulate weather conditions, and it actually makes surprisingly little difference what the clouds are doing.

I'm interested to know more about Hydrogen leaking through most materials though. Where can I read about this? I wasn't taught chemistry at school.

It's called permeation: https://en.wikipedia.org/wiki/Permeation, although reading up on it I don't think it happens fast enough to lose any significant gas pressure, just mess with the storage vessel.

I think ultimately the best solution is a mix of technologies; electric and hydrogen, plus some hybrid tech. Hydrogen's just not the magic bullet the media makes out (because the media's understanding of science is terrible).

[Joe Harding]

Nah, just a great big rubber band connected to the wheels that is twisted at a band twisting facility at every garage.

[Joe of Loath]

I think I've driven cars that could have been improved by a rubber band engine swap...

[MarvinMitt]

Here's an article published April 26, 2015, which considers problems of solar photovoltiac technology.

http://www.lowtechmagazine.com/2015/...lar-power.html

Despite being almost 2 years old, it still gives a good idea about emissions and energy balance and production trends of the PV solar industry.

[MarvinMitt]

The technology is always progressing and people need to be funded to do so. But mass production of chinese solar panels is not yet the market I'm supporting, and panels made with renewable or recyclable resources is not yet something I can afford.

If it's about CO2 emissions then let's just stop eating meat every time we raise a fork to our mouths, and I can semi-proudly say I eat meat only 2-3 times a week in my workplace's canteen where it's mixed with the rest of the food.

https://www.theguardian.com/environm...more-than-cars

[ronmanager]

I have my D5 XC70 that I love but our other car is a 0.9 Fiat 500 Twin Air which has sub 100g emissions. So one cancels out the other as far as I'm concerned!