General > General Technical Chat
The Electric Vehicle Future: Where is all the power going to come from?
nctnico:
--- Quote from: richard.cs on February 14, 2020, 12:03:07 pm ---
--- Quote from: nctnico on February 14, 2020, 11:21:28 am ---There is no time to do an EV transition in order to meet the goals of the Paris agreement. That is the whole kicker!
--- End quote ---
The infrastructure has to meet the actual requirements of the cars on the roads, which are growing fairly slowly. Yes we could do with a more rapid transition, but the cables in the street only need to power the cars that actually exist rather than the ones we wish existed.
--- End quote ---
You are missing the point. The goal is to reduce CO2 emissions short term. It is clear EVs aren't going to help with that. By the looks of it there are better ways to achieve the goals quickly. So where does that leave EVs? Some are calling EVs a temporary solution.
--- Quote ---Biofuels need land area, fertilisers, etc. and compete with resources for food crops. I suspect they will be part of the solution, but the quantity available will be limited so they will get used on the things most difficult to do without energy dense liquid fuels, aviation perhaps.
--- End quote ---
That is old thinking. There is a new breed of bio-fuels slowly but steadily taking over: the kind that is made from the parts of the plants we don't eat. So instead of competing with food production these bio-fuels help make food production cheaper because more of the plants is used. From many plants only the seeds get eaten and the rest of the plant is discarded. The conversion process (even though it basically comes down to brewing beer and distilling it) isn't easy but a few companies have cracked this problem and are currently running industrial scale factories.
And I don't see why hydrogen causes big problems. It is already used widely in the industry so transport and storage are solved problems. Toyota just introduced an updated version of their Mirai hydrogen car. If you compare hydrogen transport and storage to that of electricity then hydrogen is cheaper and easier. Australia with their large deserts and stable political climate would be ideal for a massive solar to hydrogen industry. Hydrogen can be transported using ships around the world. You can't do that with electricity; you need to generate and store that locally. I've seen a report about Germany which states a hydrogen infrastructure is 4 times cheaper compared to that for electric vehicles. Also China is investing a lot in hydrogen lately because EVs aren't cutting it.
--- Quote ---If batteries became that good, why would people (the subset with driveways at least) not want to charge at home?
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Depends on where you are but in the Netherlands 70% of the households doesn't have a driveway. 30% of the homes in the west part of Belgium doesn't have a mains connection which is suitable to charge an EV (something to do with split phase). Also why would you want to plug in your car every day if you can fill it up once a week (or even less) at a supercharger? In the end the reason is the same where it comes to putting fuel in your car. Do you want to mess around with it at home? What if you have two cars but only one driveway? You want to go out of bed every night to swap the cars around. And not to forget that batteries may need active cooling/heating while charging which is likely to cause noise due to pumps and fans running. Some Tesla owners are not happy with the noise the car makes while it is charging outside. These are the little details which are often overlooked.
richard.cs:
--- Quote from: nctnico on February 14, 2020, 12:56:29 pm ---You are missing the point. The goal is to reduce CO2 emissions short term. It is clear EVs aren't going to help with that. By the looks of it there are better ways to achieve the goals quickly. So where does that leave EVs? Some are calling EVs a temporary solution.
--- End quote ---
It leaves them as a partial solution to a big problem, a problem that if we manage to solve it will be done by many such partial solutions. They are also quite nice cars to drive, and an excellent solution to local air quality problems.
The real problem is that vast numbers of people have gotten used to a massively energy intensive lifestyle, and trying to change that in a short enough timeframe is doomed to failure. As a result we need to find some way to to support that energy intensive lifestyle with lesser CO2 emissions.
--- Quote from: nctnico on February 14, 2020, 12:56:29 pm ---
--- Quote ---Biofuels need land area, fertilisers, etc. and compete with resources for food crops. I suspect they will be part of the solution, but the quantity available will be limited so they will get used on the things most difficult to do without energy dense liquid fuels, aviation perhaps.
--- End quote ---
That is old thinking. There is a new breed of bio-fuels slowly but steadily taking over: the kind that is made from the parts of the plants we don't eat. So instead of competing with food production these bio-fuels help make food production cheaper because more of the plants is used. From many plants only the seeds get eaten and the rest of the plant is discarded. The conversion process (even though it basically comes down to brewing beer and distilling it) isn't easy but a few companies have cracked this problem and are currently running industrial scale factories.
--- End quote ---
I agree progress is being made but it is far from a solved problem to do on sufficient scale, with acceptable levels of external energy input, and whilst keeping a closed nutrient cycle (waste parts of food crops are normally ploughed back into the soil). Another partial solution just like EVs, and if you are going to have a mix of EVs and biofuels it makes sense to use the biofuels where the energy density is essential.
--- Quote from: nctnico on February 14, 2020, 12:56:29 pm ---And I don't see why hydrogen causes big problems. It is already used widely in the industry so transport and storage are solved problems.
--- End quote ---
High pressure hydrogen has a low energy density and low specific energy when you include the weight of the containers.
Cryogenic hydrogen is much better in that regard but is still a long way off liquid hydrocarbons because even liquid cryogenic H2 isn't very dense. It's clearly the best option for bulk transport but it scales poorly because small tanks have a lot of surface area compared to their volume so boil-off becomes a problem.
Last time I looked most H2 cars were using metal hydrides as storage. That keeps the pressures more sensible but again it eats into specific energy. It is probably the only practical solution for vehicles, but is totally different technology from that used in industry which seems to be high-pressure for small quantities and cryogenic for large ones.
--- Quote from: nctnico on February 14, 2020, 12:56:29 pm ---
--- Quote ---If batteries became that good, why would people (the subset with driveways at least) not want to charge at home?
--- End quote ---
Depends on where you are but in the Netherlands 70% of the households doesn't have a driveway. 30% of the homes in the west part of Belgium doesn't have a mains connection which is suitable to charge an EV (something to do with split phase).
--- End quote ---
Again, it's a partial solution that's not applicable to everyone, that doesn't make it suitable for no-one. Note that the Belgium problem is essentially a solvable mixture of engineering and paperwork - the 220 V phase-phase delta system is just a bit oddball and sufficiently niche that charger standards and car manufacturers don't account for it (many cars would charge from it just fine, but it upsets things like safety interlocks if they're not designed to expect it).
--- Quote from: nctnico on February 14, 2020, 12:56:29 pm ---Also why would you want to plug in your car every day if you can fill it up once a week (or even less) at a supercharger? In the end the reason is the same where it comes to putting fuel in your car. Do you want to mess around with it at home? What if you have two cars but only one driveway? You want to go out of bed every night to swap the cars around. And not to forget that batteries may need active cooling/heating while charging which is likely to cause noise due to pumps and fans running. Some Tesla owners are not happy with the noise the car makes while it is charging outside. These are the little details which are often overlooked.
--- End quote ---
Personally I love that I don't have to go to a petrol station when I drive my girlfriend's EV (our main car), it feels like such a pain now when I have to go out of my way to fill up my petrol car, or queue or worry about petrol station opening times. If we're talking about a car that only needs charging once a week then why would you swap the cars over every night? A need for heating and cooling is associated with high power charging which I am not convinced is needed for home charging.
tom66:
From a UK perspective switching ALL private transport to electric would require approximately 20% more electricity generation.
An EV uses energy about 4~5x more efficiently than a gasoline vehicle. In addition we have around 15% "spare" capacity at any one time (our electricity usage is dominated by a winter peak which is driven by resistive heating in off grid homes).
It will require new power generation but certainly nothing more than a few power plants (but hopefully renewable energy plants).
One benefit that is not often classified is that EVs can draw energy when there is an excess of supply - e.g. a smart charger could supply an EV when renewable plants would otherwise have to shut down to avoid oversupply conditions. A colleague of mine charges his EV on night time electricity where the price can often be less than 1p/kWh. He shifts demand away from the evening peak where possible. Home solar systems can also be configured to send a "start charging" command to a car when more sun is available than can be absorbed by other loads in the home, and the Type2 standard supports variable charge current from 5 ~ 32A single phase, with the car reducing current within 10 seconds of the command being issued, allowing the ebb and flow of solar energy to be precisely tracked.
donotdespisethesnake:
--- Quote from: nctnico on February 14, 2020, 12:56:29 pm ---Australia with their large deserts and stable political climate would be ideal for a massive solar to hydrogen industry.
--- End quote ---
For some weird reason large deserts are not ideal sources of hydrogen. :palm:
You also completely contradict yourself. You literally just said massive areas for solar are impractical, now they are? As we have seen many times before, the lack of consistency and logic in your arguments seems like trolling.
nctnico:
--- Quote from: donotdespisethesnake on February 14, 2020, 03:11:59 pm ---
--- Quote from: nctnico on February 14, 2020, 12:56:29 pm ---Australia with their large deserts and stable political climate would be ideal for a massive solar to hydrogen industry.
--- End quote ---
For some weird reason large deserts are not ideal sources of hydrogen. :palm:
You also completely contradict yourself. You literally just said massive areas for solar are impractical, now they are?
--- End quote ---
Where did I ever state massive areas for solar are impractical? I didn't. In densely populated areas solar is expensive due to land costs (so economic viability becomes an issue) and you'll still need the storage as well. Also solar panels work much better in areas with a lot of sun close to the equator. This automatically translates to areas where they have large deserts. Australia is a very good choice both geographically and politically. Put a solar farm in a desert, transport the electricity to a harbour where it can be converted to hydrogen using sea water and use the same seawater to float a big tanker which can then take the hydrogen whereever it needs to go (the tanker itself can be powered by hydrogen as well). This is not a solution for today but it can be in say 5 to 15 years from now.
You can't deny solar and wind need massive amounts of land area and in some places land is scarce. So a solution which allows to take energy from one place to another may turn out to be more economical compared to generating all electricity locally.
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