General > General Technical Chat
Confused about PHEV, Hybrids, etc...
tom66:
--- Quote from: gnuarm on August 18, 2022, 08:49:49 pm ---This is the sort of stuff people from the UK give me all the time. There are some who have BEVs and discuss rationally how they charge in their garage or driveway. None of them have needed new feeds from the street! You must think a BEV requires a direct connection to a nuclear power plant to charge! I charge my Tesla model X from a 120V, 15A outlet that provides 1.44 kW to the car which puts just 1 kW into the battery. In the UK, you don't even have such low power outlets, do you?
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I'm charging my PHEV from an extension lead run out of the kitchen window! That's 2.3kW. About the lowest you would normally charge a car on around here... Still, it shows that you can install EV charging even if you rent. The total cost of the infrastructure was... about £20 for a heavy duty waterproof lead from the DIY store.
I'll put a proper EV charger on the wall once I move in to the new place.
gnuarm:
--- Quote from: Miyuki on August 18, 2022, 07:59:57 pm ---
--- Quote from: tom66 on August 18, 2022, 05:21:12 pm ---No one says 100% BEV by tomorrow. It will transition over the next 15-20 years. There will still be ICE on the road in 2040.
The power generation argument is idiotic. VW e-Golf is 4 miles per kWh... average let's say of 12,000 miles per year... So we need an extra 3,000kWh per car.
UK has 30 million cars - so extra generation of 90TWh. Country generated 323TWh last year.
So yes... It is a lot... But also it is not that much - about 25% of total generation. It seems completely feasible over the course of 20 years that generation could increase by 25%. It will, after all, need to increase as gas heating is phased out. The beauty of EVs is they can charge any time they are parked up, so they are great for soaking up excess renewables.
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There will be some offset by this:
"it takes around 2 to 3kWh of electricity and 2 to 3kWh of heat energy (DOE figures) to produce a gallon of gas"
If the numbers are correct then it is a significant portion of the electricity needed for EVs when switched from ICEs
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I've looked for substantiation of these numbers and it is not to be found. The "heat energy" is not particularly relevant unless the source of that energy is given. The 2 to 3 kWh of electricity is probably more like 0.5 kWh. If I find the sources of this info, I'll post it here.
--- Quote ---Vanadium flow batteries are around for at least a decade yet is anywhere any working installation?
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By "around" you mean they were invented a decade ago. So? Why is that relevant? The application of grid storage is very recent and every technology for that purpose is relatively new. Lithium ion batteries are only used for grid storage because of the advances in production from Tesla's use in autos. Now we need similar advances in production for vanadium flow batteries.
--- Quote ---Hydrogen storage might a necessity in European conditions
Because you need to withstand a winter when you have minuscule solar power and wind can stop blowing for weeks (it happens quite commonly)
So to be able to have fossils as a backup for the worst case you need about 1 week of storage (for peak draw power as it happens in the same time)
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Sorry, that doesn't make sense. How does a need for "fossils" turn into storing hydrogen? If you are going to use fossil fuel, why not just store that?
--- Quote ---And to be 100% renewable + nuclear it will have to be at least one whole month worth of energy
There is no way around it. Sahara solar farm is not a realistic approach as it is not a stable region. And you won't be able to transfer energy across Europe anyway.
So some huge chemical storage is a must.
In the US it can be significantly different.
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Don't forget that nuclear requires storage. It has the opposite problem of renewables which are intermittent. Nuclear is not easy to scale back. Not only is that uneconomical, but if you try to ramp it up and down for the daily cycle, you end up xenon poisoning the reactor. So it needs to store energy at the slack demand times so it doesn't get throttled back, then it needs the additional energy reserve to power the peak times.
The US also has political instability issues. Texas, a very large region, is an independent grid. So the rest of the US has to operate around them, even though they are an ideal location for wind power. I'm hoping they will secede so we can treat them as a foreign country, possibly hostile.
gnuarm:
--- Quote from: tom66 on August 18, 2022, 08:08:15 pm ---
--- Quote from: 2N3055 on August 18, 2022, 07:32:24 pm ---As for when people are charging, you can see the pattern by looking at parking patterns. Pretty much, it will be happening overnight. All of them at the same time.
When they are home from the office, and all other activities. 7 kW is not enough power though, you need at least 16kW to charge it in reasonable time. Average of 50km is not important again, but a peak drive.. If I have to go Rijeka-Zagreb two days in a row (something very common here) I need to charge for 2 X 360-380 km in two days. And that has to be range, about 400km on a charge.
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There aren't many EVs (or any currently made, that I'm aware of) that go above 11kW, or 16A x 3ph, so I'm not sure 16kW is a near-term requirement. Of course, it could change.
The capacity issue is mostly down to average usage though.
There is nothing in principle wrong with using the average journey distance to calculate grid loading - so if the average daily usage is 20 miles then a user will need 5kWh per night in charging. That is 7kW for less than an hour, or 3.6kW for just under two. The grid already handles - with some margin for capacity - peak times when cookers are switched on, or morning time if you have electric showers (9kW+ per home) and similar.
The point of using the average is of course there will be cases where you need 7kW x 8 hours twice in a row - but it's unlikely everyone on the street will need it. And most homes in Europe have at least 40A single phase service so can support 16-24A EV charging. Many homes in Europe have 3ph in which case EV charging is even better because it sits equally across all three phases, even at lower powers. No diversity or phase-balance calculations to make.
The biggest issues are not on the cables to each home but at the distribution network between those - it's common that there might only be a 300A x 3ph cable feeding a whole street. This may need to be replaced, depending on the load, but that can be monitored and upgraded as needed. At the low-voltage to medium-voltage transformer, it's possible there will need to be larger transformers fitted, or upgrades to the 11kV (or other AC voltage) lines - that could get expensive. But I'm not sure I'd be that worried by space for a bigger transformer. Transformer design has only improved since some of those have been installed. A 3MVA transformer fits in a 2m x 2m box, and that's enough to support an Ionity fast charging station.
For what it's worth I know two people who work in the distribution network here - National Grid plc - and they both tell me they are very on board with EVs. They are giving their employees who have a driveway a company electric van, and are converting the fleet to EVs. See, the distributor gets paid the more kWh's flow, so it really is in their interest to make sure they can allow it. Their biggest short-term concern, for the UK, is building more HV transmission lines to allow the renewable power in Scotland to make it to the rest of the UK, as at present there are only two 400kV (~10GW each) links connecting the two halves.
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I understand that it is very common for the majority of homes to switch on the kettle at the same time during commercials on the TV, especially for football matches. I think that is 2 kW per house, 9 amps, right?
You can actually charge a BEV quite well on that power level. I'm getting by with less.
2N3055:
--- Quote from: gnuarm on August 18, 2022, 08:42:04 pm ---
Or you stop for 10-15 minutes along the way, have a coffee and hit the bathroom. You can get up to 200 miles or even 321 km in that time. If you are going to whine that this is not reasonable, then I guess you can keep your gas burner and be the last guy driving an ICE in 2050.
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There are very few chargers on the way. All of them are slow and usually taken by desperate ones.... Also I don't have time to faff around. I need to get there and back without wasting additional time.. 15 minutes charge on slow charger is not helpful. 2 hours I don't have just because I made a wrong decision to buy a car the doesn't serve my usage patterns..
I don't serve my car purposes. It is the other way around. Until BEV serves my lifestyle as well as gasoline burner and is affordable to me to buy, no BEV for me. And that is how it is for 90% of all population. THAT is the reason why there no more BEVs on the street. These people are not anti green. They just cannot afford it. In more ways than just price to purchase it.
Monkeh:
--- Quote from: gnuarm on August 18, 2022, 08:31:59 pm ---
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And I'm sure you're quite happy to go and invest tens of thousands of dollars into a vehicle which is impractical for you with no foreseeable change to that fact. The rest of the world has other ideas.
--- Quote from: gnuarm on August 18, 2022, 08:49:49 pm ---This is why I typically don't discuss BEVs with people from the UK. They managed to essentially run the world at one point, but today can't seem to be able to wire a 240V outlet.
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The issue here is that you are arguing from a point of profound ignorance as to the reality of living in this country.
Running cables to a dwelling was brought up as an example of the cost of running underground cabling. The reverse would be required for a house to provide its own charging point at the roadside, or similar work required to provision charging up a street on behalf of the houses there by, say, a local council, or a private company providing charging facilities.
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