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| The Electric Vehicle Future: Where is all the power going to come from? |
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| jogri:
--- Quote from: edy on February 14, 2020, 01:57:02 am ---Most of the energy will go directly into movement and not lost as heat or just keeping the engine idling. --- End quote --- Well, that "lost energy" is the reason why you're not freezing... And since EVs don't provide that kind of losses you have to convert your limited supply of electrical energy into heat, draining your battery even faster. Sure, that problem doesn't occur in california, but here in europe it's a different story. Or to quote one of my friends who develops eletric heaters for EVs: "You can either park in a warm car or drive a cold one." |
| richard.cs:
--- Quote from: peter-h on February 14, 2020, 09:18:36 am ---The immediate issue is distribution at street level. --- End quote --- Agreed. It needs handling, but there is a lot of work in progress on that, specifically on optimising the use of existing infrastructure (cables, transformers, etc.). Some upgrading is inevitable, but there is time to do it. --- Quote from: peter-h on February 14, 2020, 09:18:36 am ---A few Teslas on a street, each charging at say 20kW (which itself needs an upgraded feed to the house, probably 3 phase) and the transformer at the end of the street will blow up :) So there is no way EV will work for serious commuters. --- End quote --- 20 kW home charging is neither necessary nor desirable. Even serious commuters are going to spend at least 12 hours at home, and in the UK are unlikely to be travelling much more than a 200 mile round-trip daily. Something like 60 kWh should be enough for that commute, and a bog standard 7 kW single phase charger will manage that in 9 hours or so. Yes some people travel further regularly, but it is uncommon (here) and there are solutions to do it with EVs. We did make a mistake in the UK in giving domestic consumers high-current single-phase supplies rather than modest 3-phase ones like most of Europe. That piece of history is going to bite us, but at least we didn't standardise on 110/220 split phase. That brings in all sorts of excitement when you try to combine it with three phase. --- Quote from: peter-h on February 14, 2020, 09:18:36 am ---EVs will work for little cars doing short journeys, and a lot of people do that. What we don't know is how many people are willing to limit themselves to a little runabout vehicle, with little or no heating or aircon, when everything suggests people want the opposite. They could also run a big car like a Tesla but again only if they don't drive it much. --- End quote --- Vast swathes of UK households own two or more cars, where at least one is only ever used as a short distance runabout. People who never drive far buy long-range vehicles for the corner cases, stuff like long distance holidays and so on. Very few actually need more than one such vehicle. Bear in mind that the 2013/14 average commute distance in the UK was 8.8 miles - much of the car owning population just don't drive very far. I am not really sure where you've got the idea you can't have much heating or air con. Yes, it impacts range a bit but so what - I have been known to turn the heating/AC off on my EV to eek a few extra miles out but it's the exception rather than the norm (and I have done it on petrol vehicles too, heating might be "free" but AC has a noticeable fuel cost). Heating wise EVs behave like any other modern car with climate control except you don't need the engine running or to wait for 150 kg of cast iron to heat up before you can demist. The only thing you can't do is whack everything up to the max and expect it to blast in 10+ kW of raw heat like you might do in a leaky 1980s car to try and dry out the footwells. --- Quote from: peter-h on February 14, 2020, 09:18:36 am ---And modern diesels are really efficient. A VW Golf will do nearly 70mpg on a long run and amazingly averages over 50 in slow moving traffic. I never saw that in my petrol days; 10mpg in traffic was normal. When you get to the stage when you are filling up the tank only once a month, the case for getting rid of it is exactly zero. --- End quote --- The financial case maybe, though that depends rather on the price of a tank. The environmental case, both from a local air quality perspective and from a wider CO2 emissions one certainly doesn't drop to zero. Air quality in my city is awful, and modern diesels are a major contributor. |
| nctnico:
--- Quote from: richard.cs on February 14, 2020, 10:55:50 am --- --- Quote from: peter-h on February 14, 2020, 09:18:36 am ---The immediate issue is distribution at street level. --- End quote --- Agreed. It needs handling, but there is a lot of work in progress on that, specifically on optimising the use of existing infrastructure (cables, transformers, etc.). Some upgrading is inevitable, but there is time to do it. --- End quote --- There is no time to do an EV transition in order to meet the goals of the Paris agreement. That is the whole kicker! On average a 100% transition to EVs will need about 25% extra generation capacity. Most countries are already struggling to get to a significant amount of renewable electricity for the current electricity consumption. Let alone that consumption increases by 25%. On top of that there will also be a higher demand for electricity for heating as well in countries which are (traditionally) using natural gas to heat homes and need to switch to heat pumps. Over here politicians bring up nuclear power regulary. And nobody knows for sure whether the investment in EV infrastructure pays off. What if bio-fuels and/or hydrogen turn out to be better alternatives (Toyota seems to believ they are) or batteries become so good you only need superchargers and 'charging at the doorstep' becomes a thing of the past. |
| GeorgeOfTheJungle:
--- Quote from: Dundarave on February 14, 2020, 01:34:43 am ---that’s 263.8 million kWh per day of new generation capacity needed according to my calculations. --- End quote --- The generation capacity is there already, but only in off peak hours. |
| richard.cs:
--- 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. --- Quote from: nctnico on February 14, 2020, 11:21:28 am ---On average a 100% transition to EVs will need about 25% extra generation capacity. Most countries are already struggling to get to a significant amount of renewable electricity for the current electricity consumption. Let alone that consumption increases by 25%. On top of that there will also be a higher demand for electricity for heating as well in countries which are (traditionally) using natural gas to heat homes and need to switch to heat pumps. Over here politicians bring up nuclear power regulary. --- End quote --- Personally I distribution as the bigger technical challenge but generation is still important. Note the current large different between peak and average demand and corresponding poor utilisation of the generation assets - we have sufficient powerstations to provide peaks at weekdays 5pm in midwinter, and then at all other times we don't run them all. That's good to some extent because some of the ones we use to handle the peaks are very polluting, but there is a significant amount of capacity available outside of peak times. Nuclear inevitably has to be a part of the generation, especially in the short-medium term. It's main problems are political rather than engineering, something it seems to share with on-shore wind. --- Quote from: nctnico on February 14, 2020, 11:21:28 am ---And nobody knows for sure whether the investment in EV infrastructure pays off. What if bio-fuels and/or hydrogen turn out to be better alternatives (Toyota seems to believ they are) or batteries become so good you only need superchargers and 'charging at the doorstep' becomes a thing of the past. --- End quote --- These things are possible but in my opinion unlikely. All investment has risks. 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. Hydrogen is a bugger to store and not that efficient to create. In fact it's such a pain to store and transport that the best approach is probably to stick it to some carbon atoms. Electrolytically produced hydrogen + carbon from biofuels to create synthetic propane for instance, about the most hydrogen-rich thing that will sensibly liquefy. If batteries became that good, why would people (the subset with driveways at least) not want to charge at home? |
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