??? What's a common sense viewpoint: Petrol-based charging grid for electric car - Page 1
Forum section: electronics / general

author: RJSV
author_rank: Super Contributor
timestamp: April 04, 2021, 02:54:32 am
content: Hi, last night TV host was speculating, saying "even an old-school gas fired generation plant, charging an electric car has got to be more efficient..."Plus, then, he added that a typical (gas) combustion engine is only 10 % efficient. I sense that he was using an old, tired trick: quoting mostly correct statements out of full context.??I toured a big electricity generation plant, back in school days: the bigger gas turbine systems got something like 85 % efficiency.But I still don't buy the whole package, of gas to electric power to batteries, to, finally, an electric motor.Certainly, cleaner electric sources may help, and the electric car market looks awesome.What's a sensible view, there ?Thanks.

author: wraper
author_rank: Unknown
timestamp: April 04, 2021, 02:58:14 am
content: ICE is certainly more efficient than 10%. However electric is still way more efficient, even if you burn gasoline at power plant and account for energy transfer and charging losses.

author: RJSV
author_rank: Super Contributor
timestamp: April 04, 2021, 03:22:51 am
content: Thanks, wrapper.I think those answers about overall efficiency appear in various forms in this eevblog forum, but I needed a clear statement.Plus, electric car infrastructure helps reduce things like oil changes potentially getting into ground water.And makes EV panels an attractive replacement, as far as solar panels can take us, today.The over-all system we have been using, traditionally also includes the gasoline delivery trucks needed, from local refinery, etc.(I think maybe I don't trust my TV host(s), anymore (lol)).

author: SilverSolder
author_rank: Super Contributor
timestamp: April 04, 2021, 01:23:02 pm
content: ICE is only efficient under load... i.e. 60% - 70% of max power is usually where the peak efficiency is found. A hybrid drive train lets you use a smaller engine that can then operate in this region more of the time - winner.Consider the implications for a big V8 engine....

author: Someone
author_rank: Super Contributor
timestamp: April 08, 2021, 06:24:21 am
content: https://www.eevblog.com/forum/renewable-energy/electric-car-experiences/msg2598654/#msg2598654Energy is energy, cars are being pushed to ever cleaner local emissions (makes sense as they are used in cities near people) which has decreased their efficiency from the achievable peaks. "Efficiency" of large scale power stations depends heavily on their accounting and sinks for the lower value thermal energy.

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 08, 2021, 05:29:27 pm
content: Quote from: wraper on April 04, 2021, 02:58:14 amIndeed. 30% is a more reasonable average estimate. Of course, in certain use cases, it WILL go down to 10% or even less. Using worst case figures (for the current situation) and best case figures (for the new miracle solution) is a common deceptive practice.Quote from: wraper on April 04, 2021, 02:58:14 amUh huh. I'd definitely like to see real figures about that, and again not just best cases figures just to make a point. I'm certainly not as optimist. And don't forget to factor in the overall cost of manufacturing and recycling the batteries into the whole analysis.

author: Ice-Tea
author_rank: Super Contributor
timestamp: April 08, 2021, 05:57:31 pm
content: Doesn't sound reasonable. Electric cars take about 20kWh to run 100km. With power plant efficiencies of 50-60% (and those are state of the art) that takes about 4kg of fuel or so. Running an ICE would take more like 5kg. So, that leaves something like 20 - 25% for transmission and conversion losses and roundtrip battery efficiency. Sounds like a break-even to me. And as you also have to factor in manufacturing and recycling of the battery it looks like a bust to me.

author: RJSV
author_rank: Super Contributor
timestamp: April 24, 2021, 06:35:28 pm
content: Thank you, SiliconWizard, Ice-Tea:Yeah, first I wanted that statement, clearly made, no 'dancing' around: That's saying things are more efficient, in total, using PETROL fired main generation of electricity, and then charging EV cars.I'm thinking, also, there is likely significant loading effects on the electric supply grid, from the massive numbers of cell-phone charging. Although admittedly that's a phenomina of orders of magnitude smaller.As for 'trust', in delivery of such overall efficiency, stated; Haha, yeah, uh no (blind) trust, there.I'm reminded of a childhood trick: you the 'one walkie-talky radio', then your parents are locked-in, forced to buy you that 'second' radio.But EV panels have lots of uses, perhaps even when overall resource use is up, often saving on messy cable runs, etc. I have been using my (solar) phone charger, on mini USB. But that's like, 1 1/2 watts.Oh well... RJ

author: Ice-Tea
author_rank: Super Contributor
timestamp: April 24, 2021, 06:41:06 pm
content: Cell phone charging is peanuts. For reference: you can charge 10 phones with the same power as an old school incandescent light. You can charge 5 000 000 phones or more with the power from a Tesla supercharger.

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 24, 2021, 06:56:18 pm
content: Quote from: Ice-Tea on April 08, 2021, 05:57:31 pmhttps://reneweconomy.com.au/tesla-ev-charged-with-diesel-generator-still-cleaner-than-conventional-car-61942/The Tesla wins in fuel costs even when compared to a very efficient conventional car, albeit by a thin margin. With a more fair comparison using a conventional car of similar performance (which would likely be far more expensive than a Tesla), there would be a huge difference in efficiency.Quote from: RJHayward on April 24, 2021, 06:35:28 pmLikely offset many times over by CFL and LED bulbs replacing incandescents. Perhaps EVs can be offset in a similar manner if we encourage the adoption of other energy saving technologies like smart HVAC systems.Quote from: Ice-Tea on April 24, 2021, 06:41:06 pmMore like 250kW/10W = 25,000.

author: David Hess
author_rank: Super Contributor
timestamp: April 24, 2021, 11:26:08 pm
content: Quote from: Ice-Tea on April 08, 2021, 05:57:31 pmThe analysis of efficiency is instructive but irrelevant to the owner; what matters is the economics. I am already hearing complaints from owners of EVs in areas where electricity costs are high making them more expensive than ICE vehicles per mile.Total cost of ownership is another thing but maintenance costs of ICE vehicles is effectively subsidized by economy of scale and batteries are expensive.

author: Someone
author_rank: Super Contributor
timestamp: April 24, 2021, 11:41:19 pm
content: Quote from: NiHaoMike on April 24, 2021, 06:56:18 pmYes, we already linked to your pet link and the discussion about why its misleading:Quote from: Someone on April 08, 2021, 06:24:21 amMuch of the electric car world is pushing simultaneous claims of energy efficiency, clean, and low cost. Except they don't all occur at the same time. There are too many abstractions (layers of smoke and mirrors) to make such simplistic comparisons. I'd be guessing most electric cars are polluting more (both over their life, and incremental per km) as the electricity sources used are so poorly regulated in comparison to new ICE vehicles.Real world electricity emissions:https://www.epa.gov/energy/greenhouse-gases-equivalencies-calculator-calculations-and-references700g/kWh, 15kWh per 100km, 100g/kmwhich is right where efficient ICE cars are, it gets worse if you include other pollutants into the mix as power stations don't control those nearly as tightly as passenger vehicles. Want to buy "green energy"? you can just as easily/cheaply buy "green fuel" with the same dodgy accounting practices applied to pretend like the emissions aren't happening.Quote from: Ice-Tea on April 24, 2021, 06:41:06 pm20min, 2 cars each to half capacity, so around 40kWh x 2 cars, which is more like 5,000-10,000 phones filled in the same time. Even if a little exaggerated, still a good way to put it in context:https://www.withouthotair.com/c19/page_114.shtmlTransport is a huge energy cost of current society, and its not sustainable.

author: RJSV
author_rank: Super Contributor
timestamp: April 25, 2021, 03:56:30 am
content: Thanks: David Hess, for your input about high electric bills, for running an EV battery charger (overnight, etc).My thoughts along the lines of 'available' square footage, of solar panel installation, vs projected volume of EV cars, and of course projected solar plant expansions.Say, 40 mile total daily commute, using XXX kw-hours, and, say, 30 million cars (I haven't a clue, what the actual figure is!). What, then, is the projected land use requirement, (and practical constraints thereof)?I'm learning the so-called, coffee napkin estimates, in those hilarious videos, exposing 'Solar Roadways' fiasco(s).================≠=========================HUMANS: They've got some great 1950's rock n roll... but maybe seem a bit lost, as they (we) muddle through the other stuff...==========================

author: Ice-Tea
author_rank: Super Contributor
timestamp: April 25, 2021, 07:21:58 am
content: Quote from: NiHaoMike on April 24, 2021, 06:56:18 pmAppologies, yes, you're entirely right. Brain fart. Doesn't change the premesis: cell phone charging means nothing.

author: Ice-Tea
author_rank: Super Contributor
timestamp: April 25, 2021, 07:52:07 am
content: Quote from: RJHayward on April 25, 2021, 03:56:30 amCurrent energy consumption:Roughly double that to include EV. Finding the space is not the issue, the fact that its unreliable and unevenly distributed is.

author: tszaboo
author_rank: Super Contributor
timestamp: April 25, 2021, 09:09:06 am
content: So they are inventing a plug in hybrid, where the ICE part is in a fixed location.It is kind of ironic, and it shows that the entire EV adaptation is going too fast, and skipping the plug-in step is a mistake.As I said already before, you can build 10x the amount of cars, if you make plug-in, instead of EVs, or 100x, if you make regular hybrid. Regular hybrid will have 30% better energy consumption than ICE. Plug in could be utilized to some 50-70% better than ICE. Result is much more reduction of CO2 and crap into the atmosphere. But still, all the governments completely forgot about plug-ins, and it shows that they don't care about the environment, its about lobbyism. And they support cars, that an average joe cannot afford, and this continues to be this way, until the battery manufacturing is the bottleneck. And I'm not against EVs, I'm just realistic.

author: RJSV
author_rank: Super Contributor
timestamp: April 26, 2021, 03:18:02 am
content: ...Wait a second: ?? Were you just saying, a customer still keeps the engine part (or ICE), but it is mounted stationary, like behind the garage? So the 'hybrid' car charges up at home, but not on a grid? First thought there is around the gas supply, and hazardous operations, by my old, aging Aunt Bessie...My imagination straining on this one? Somebody clarify that 'stationary' means, not moving about, with carHmmm.AND, sorry Ice-Tea, did you just say; " yeah, go ahead and (grab) some bunch of square miles of California land?", (For supplying a national / world-wide fleet with no financial worries doing that). Looking at that world wide map... Why the heck use desert land, there? I still bet you can't just 'GRAB': Most land is, uh,...anyway not to belabour the point.Just saying, as Petrol bans linger in the wings...

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 26, 2021, 03:35:18 am
content: Quote from: RJHayward on April 26, 2021, 03:18:02 amThat can work very well in cold climates since the heat from the engine would be very useful. Decoupling things a bit, the EV doesn't have to be in the same house and things other than EVs can be powered.

author: james_s
author_rank: Super Contributor
timestamp: April 26, 2021, 04:24:36 am
content: Things could get interesting in a cold climate, using a diesel generator and using the cooling water for the diesel to provide hot water and heat for the building. I still don't think it would make sense for most people but there are niche applications where it could work well. I wouldn't bother with gasoline, a diesel is much more efficient, especially when you factor in maintenance. The big advantage you'd get vs putting the engine in the car would be running the engine constantly right at its most efficient point vs in a car where it's all over the place, the efficiency is 0% when the car is idling in traffic and not moving. A big problem though is that this arrangement doesn't give you what is IMO the most compelling advantage EVs offer, that is not having to go get fuel. At least you could have a large stationary tank and have it filled by a delivery service though. Or use a natural gas fired generator so the fuel is piped in.

author: Ultrapurple
author_rank: Super Contributor
timestamp: April 27, 2021, 02:20:01 pm
content: I have been following this, and similar discussions, with some interest.Back along I looked into the fuel consumption of one of the popular plug-in hybrids. From what I remember the figure was something like 45 miles per (imperial) gallon overall when using the ICE as required to charge the battery.My two-ton, ten-year-old, 3 litre V6 diesel gets very similar mileage.Yes, I know that diesel and petrol are different, but still - this is hardly the massive leap in economy that is being touted as the saviour of the planet.Here in England electricity generally costs in the region of 20 pence per kWh. On the 20kWh for 100km suggested in an earlier post, that's roughly 3 miles for 1kWh.One litre of diesel presently costs about 130 pence (most of which is tax). That's the same cost as 6.5kWh, or 20 electric-miles.At 45.4mpg (imp) (a convenient figure not far off what I get for my car*), that's 10 miles per litre of fuel.So the all-electric cost per mile is half that of the dieselmobile.But I mentioned that the fuel cost included taxes. According to theRoyal Automobile Club European fuel cost comparison, in the UK that 130p comprises 50p for the fuel and 80p for taxes.Re-working the fuel cost on a tax-free basis and we suddenly find that 130p buys 2.6 litres of diesel, enough for 26 miles. Suddenly the diesel car is cheaper to run.Now I do realise that the cost of electricity also includes taxes so I am making a deliberately unfair comparison, but if nothing else it goes to show that one can pick one's variables to suit the argument.Recently I noticed that home off-grid natural gas-fuelled generators are becoming a thing here. Natural gas costs the equivalent of about 3.5 pence per kWh. Making the big assumption that one could get as much as 33% efficiency pipe-to-plug, on the face of it there seems to be no reason why one shouldn't generate one's own electricity for about 10p per kWh, or half the grid price.I know I am conveniently ignoring the purchase cost of the generator, maintenance, load factor and suchlike. I just toss this into the mix to ask the question whether a natural gas powered generator would be a cost-effective way to charge your electric car...?* I get about 42mpg (imperial) overall, or a touch over 50mpg on highway driving. I can get mid-50s if I am careful (=slow) on the highway.Please don't flame me. With all the diesel, petrol and natural gas in this post, you risk triggering a veritable conflagration.

author: james_s
author_rank: Super Contributor
timestamp: April 27, 2021, 05:25:55 pm
content: That's something else that will be interesting as EVs gain popularity. Over here too, a very significant portion of the cost of fuel is road tax, and currently economics greatly favor EVs because there is no road tax on electricity, and you can't dye electricity to make it possible to detect untaxed electricity in the battery. Right now EVs have very favorable economics, but if too many people get them then the state will have to find some other way of taxing drivers to pay for road maintenance and there is some concern that increased demand will drive up the cost of electricity. I'm a proponent of EVs overall, but I don't want everyone to get them, one of the big advantages is spreading out the needs of society over multiple different fuel sources. Having a mix of vehicles burning gasoline, diesel, propane, CNG, and some using electricity gives us the advantage of diversity.

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 28, 2021, 03:32:20 am
content: Quote from: james_s on April 27, 2021, 05:25:55 pmThat has been invented a long time ago - toll roads.

author: james_s
author_rank: Super Contributor
timestamp: April 28, 2021, 04:36:48 am
content: Quote from: NiHaoMike on April 28, 2021, 03:32:20 amWe don't really have those here and never really have, with the exception of a few bridges. It would be political suicide to implement it, and then what about all the people with fuel powered cars who already pay a gas tax?

author: Someone
author_rank: Super Contributor
timestamp: April 29, 2021, 12:00:35 am
content: Quote from: Ultrapurple on April 27, 2021, 02:20:01 pmMost developed/western countries fall somewhere around that same 1/2-3/4 "cost" for the marginal price of energy the consumer sees. If taxation were equal for all road going energy sources then electricity ends up more expensive in most places!Quote from: james_s on April 28, 2021, 04:36:48 amThe front running scheme is distance based pricing:https://en.wikipedia.org/wiki/Vehicle_miles_traveled_taxWhich can be applied to all vehicles and replace the fuel excise. Weight/risk/environmental incentives are possible to capture quite easily. Such a scheme has different characteristics to a fuel tax so some people would be better off, some others worse off. Politics is generally shy about major changes, so it'll be interesting to see what solution is finally implemented.

author: james_s
author_rank: Super Contributor
timestamp: April 29, 2021, 04:00:35 am
content: Quote from: Someone on April 29, 2021, 12:00:35 amSeems like that would be really difficult to implement. None of my cars are new enough to have OBDII so there's nowhere to plug in a device that would interface to the car directly, and anything else I could easily leave at home or switch off. I don't see how they're going to come up with something that people won't easily game.

author: Monkeh
author_rank: Super Contributor
timestamp: April 29, 2021, 04:08:32 am
content: Quote from: james_s on April 29, 2021, 04:00:35 amWell, electric cars do have OBD2.. that you drive ancient, inefficient, and unsafe vehicles is unusual.

author: Someone
author_rank: Super Contributor
timestamp: April 29, 2021, 04:51:11 am
content: Quote from: james_s on April 29, 2021, 04:00:35 amThe simplest case is user reporting of the odometer (which is legally required to be accurate and tamperproof in most jurisdictions) and you pay that with your registration. Or like fuel cards you might report the odometer reading when you take on energy at a filling station.Quote from: Monkeh on April 29, 2021, 04:08:32 amA possible option, but unpopular with the privacy conscious. Instead despite all the possible technical ways to count road use, its back to the odometer:https://www.vicroads.vic.gov.au/registration/registration-fees/zlev-road-user-charge

author: David Hess
author_rank: Super Contributor
timestamp: April 29, 2021, 11:42:40 pm
content: Quote from: Someone on April 29, 2021, 04:51:11 amEven simpler is to tax tires, which can also roughly take into account weight which damages the roads, but why do something simple when more complexity can facilitate more rent seeking.But neither allow different road taxes for different jurisdictions. For that you need location tracking which is a privacy nightmare, but perhaps not significant with license plate readers and personal cell phones which already continuously report your location anyway.

author: SilverSolder
author_rank: Super Contributor
timestamp: April 30, 2021, 01:35:54 am
content: Quote from: David Hess on April 29, 2021, 11:42:40 pmThere are all those e-z pass "gates" you pass through if you drive in some areas of the USA, that act like automated toll collection and seems to be a pretty flexible way of doing it.

author: james_s
author_rank: Super Contributor
timestamp: April 30, 2021, 02:20:20 am
content: Quote from: Someone on April 29, 2021, 04:51:11 amHere at least after a certain age cars become odometer exempt and you no longer have to report the mileage, I think it's only around 100,000 miles when they stop tracking it, I don't even know, I dislike modern cars and have never owned anything that wasn't already exempt when I bought it. It's still illegal to deliberately roll back an odometer but it's very common for older mechanical odometers to stop and most people just keep driving the car. One of mine has a broken gear and stopped turning a while back, it's a very rarely driven classic so it hasn't been a priority but at some point I'll replace the gear and roll it forward to something near the correct mileage. The point being it's trivial to open up the speedometer and spin the little wheels to whatever value I want, or in newer cars, flash the EEPROM.A tire tax might work pretty well, although I'm not sure how well that correlates to wear on the roads. Very soft sport tires tend to wear quickly while heavy duty tires on something like a big pickup truck can last a long time. I think any kind of tax per mile driven will be easily gamed though, there will be $20 gadgets from from China that will defeat any kind of built in mileage tracking unless it's very tightly integrated into the electronics of the car.

author: james_s
author_rank: Super Contributor
timestamp: April 30, 2021, 02:29:19 am
content: Quote from: SilverSolder on April 30, 2021, 01:35:54 amWe do have the "Lexus lanes" here, which are electronically tolled HOV lanes on some of the freeways, they are unpopular and controversial though, they had a sham public commentary during which time they had already started the construction, everyone was against them but they got put in anyway and the result is that suburban areas along that stretch of highway have become clogged with drivers avoiding tolls and the jams on the remaining general purpose lanes. There was also an agreement that traffic flow had to remain above a certain speed a certain percentage of time or they had to come down. Well they didn't live up to those claims and the politicians still decided they're going to keep them anyway because they like the revenue. Like anything else of this nature it becomes embroiled in politics.I probably shouldn't even really care, I work from home, I drive around 1,000 miles a year, closer to 2,000 prior to the pandemic, my cars are toys as much as they are tools. No matter how much they tax driving not much of it is coming out of my pocket.

author: Someone
author_rank: Super Contributor
timestamp: April 30, 2021, 04:06:58 am
content: Quote from: David Hess on April 29, 2021, 11:42:40 pmNot a bad option but with a moral hazard of encouraging people to use tires beyond their safe/practical life.Quote from: David Hess on April 29, 2021, 11:42:40 pmLike with many of the "arguments" this is equally applied to existing fuel taxation where people fill up in one region and drive in another. Change is hard to sell people, even when the status quo is manifestly stupid.

author: james_s
author_rank: Super Contributor
timestamp: April 30, 2021, 04:15:30 am
content: Quote from: Someone on April 30, 2021, 04:06:58 amThat's a good point, people would of course do that, they already do just to avoid spending money on tires. As with most things, people have a tendency to over-simplify and look for nice simple tidy solutions to a complex problem.I kind of took things off on a tangent and then forgot the main point of that all, right now EVs have a substantial economic advantage due to the fact that there is no road tax on the fuel, and on top of that in many regions there are tax credits for those who drive them. If they are ever the majority then the government will find new ways to tax them and many of those advantages will go away. Best not to have all our eggs in one basket, it's better if we have cars using a variety of different energy sources rather than everyone having the same thing.

author: SilverSolder
author_rank: Super Contributor
timestamp: April 30, 2021, 02:48:24 pm
content: Quote from: james_s on April 30, 2021, 02:29:19 amJust be grateful the modern digital economy guys aren't running the "Lexus Lanes"... they would work by bidding for each mile of use, and the highest bidders would get the right to use it - so it becomes cheaper the less people want to use it!

author: james_s
author_rank: Super Contributor
timestamp: April 30, 2021, 08:34:53 pm
content: Quote from: SilverSolder on April 30, 2021, 02:48:24 pmIn a sense they already do. The toll varies based on how heavily used it is, from a low of I think 75 cents all the way up to $10 per segment. They keep traffic in the toll lanes flowing by excluding those who can't afford to use them.

author: SilverSolder
author_rank: Super Contributor
timestamp: April 30, 2021, 09:00:38 pm
content: Quote from: james_s on April 30, 2021, 08:34:53 pmThere probably isn't any better solution (than auctioning the space off) since there will always be infinite demand for a free (to the user) resource...

author: AVGresponding
author_rank: Super Contributor
timestamp: April 30, 2021, 09:15:36 pm
content: Quote from: SilverSolder on April 30, 2021, 09:00:38 pmFree at the point of use might be a better description, since I dare say some of the funds come from general taxation. They do in the UK at any rate.

author: james_s
author_rank: Super Contributor
timestamp: April 30, 2021, 11:39:28 pm
content: They absolutely come from taxation, and the toll system is run by a private corporation that takes a substantial cut of the profits. Same with the speed cameras and red light cameras.

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 02, 2021, 06:06:42 pm
content: Quote from: james_s on April 30, 2021, 11:39:28 pmYup.And always-connected EVs will be uber-easy to tax automatically wherever they drive.How to get more tax money is the easiest problem to solve ever.

author: Alti
author_rank: Frequent Contributor
timestamp: May 02, 2021, 08:09:40 pm
content: Quote from: Ultrapurple on April 27, 2021, 02:20:01 pmYou need to understand that 20p is not the electricity price but the billed price of 1kWh that includes: tax, energy, bill delivery, grid maintenance, marble arches, energy loss, etc. So you could do thatalonebut in a scale of society it does not make any sense because electricity costs 8p and the remaining (mostly fixed cost) is 12p (values as examples).

author: Ultrapurple
author_rank: Super Contributor
timestamp: May 13, 2021, 11:27:16 am
content: Quote from: Alti on May 02, 2021, 08:09:40 pmYes, you're quite right (and I acknowledge that your figures are for illustration only).But it seems I'm not alone with the idea...(Source:Using diesel to charge EVs in the outback is greener than you think

author: SilverSolder
author_rank: Super Contributor
timestamp: May 13, 2021, 01:32:18 pm
content: Quote from: Ultrapurple on May 13, 2021, 11:27:16 amI guess that if this kind of thing is only done once in a blue moon where there are no other charging facilities, the environmental impact may not be too bad (as long as you are nuclear or hydro or solar or wind powered the rest of the time!).

author: Ultrapurple
author_rank: Super Contributor
timestamp: May 13, 2021, 05:52:12 pm
content: Quote from: SilverSolder on May 13, 2021, 01:32:18 pmIt's worth reading the details set out inthe article.Selectively quoting, and adding approximate MPGimpfigures in red:Using the lifetime average kWh per kilometre for each car (this depends on the car and the driving style and is recorded continually by the car) an individual litres diesel equivalent per kilometre for each car tested can be establishedRunning the charger for 9 hours and 15 minutes and consuming 108.6 litres of diesel to charge the 10 EVs, the results came in: a total energy consumption (as recorded by the EV power management systems) of 368.4kWh delivered at an average rate of 3.392 kWh/litre.Converted to standard fuel consumption figures using the lifetime average kWh per kilometre, the BMW i3 came in as the most efficient, recording a fuel consumption rate of 4.392 litres/100km(64mpg)– about the same fuel efficiency as a diesel BMW 3 series.The Tesla models, while scoring higher than the BMW i3 (between 5.011 to 6.014 L/100km(56 - 47mpg)for the Model S and 5.689 to 6.957 L/100km(50 - 41mpg)for the Model X) came significantly under similarly sized vehicles in their range (for example, a diesel Holden Commodore does 5.7 litres/100km(50mpg)while a VW Touareg diesel SUV does 7.2 litres/100km(39mpg)).(I can't get my head round litres/100km, if only because as vehicle economy improves you have to start specifying to more and more significant figures to capture the tiny numerical changes that would be ever-so-clear in MPG terms)

author: james_s
author_rank: Super Contributor
timestamp: May 13, 2021, 06:38:25 pm
content: I did some back of a napkin calculations recently after having the opportunity to drive a Tesla Y for a few days. When charging from a 120V receptacle it can pull 12A which is about 1.4kW and charges at a rate of 5 miles of range per hour. I have a Honda EU2000i inverter generator which will deliver that power for about 4 hours or possibly a bit more on its 0.95 gallon tank so a as a rough estimation we can call that 20 miles per US gallon. That's really not bad at all for such a big heavy car, and it's even more impressive when you consider all of the conversion stages taking place here. Gasoline> mechanical energy> 3 phase AC> DC> 120VAC> DC> stored energy in batteries> AC> mechanical energy. A conventional (non-inverter) generator sized precisely for charging the car while running at the highest efficiency loading would likely improve things a bit, a diesel generator doing the same thing would be a further improvement. Does it actually make sense to do that as a matter of routine? I'd say no, but I was rather surprised by the result of the calculations.

author: Someone
author_rank: Super Contributor
timestamp: May 14, 2021, 02:33:15 am
content: Quote from: Ultrapurple on May 13, 2021, 05:52:12 pmSelective comparisons if ever there was one, Holdens being known for their complete disregard of fuel efficiency. Instead for the larger vehicles:Mercedes-Benz A Class A200CDI 4.0l/100kmPeugeot 5008 GT 4.8l/100kmAudi Q5 40 TDI quattro 5.3l/100kmAnd smaller vehicles comparable to an i3:Peugeot 308 GT 4.0l/100kmAudi A3 Sportback 1.6 TDI 4.1l/100kmPicking selectively for efficiency makes the picture entirely different. Noting that they still ignore the emissions restrictions on the cars, and claims the opposite:QuoteSo it uses more fuel in an engine with looser environmental restrictions, and is somehow "greener". No, no it isn't.

author: SilverSolder
author_rank: Super Contributor
timestamp: May 14, 2021, 05:00:26 pm
content: So a diesel generator is not required to be as "clean" as a diesel car, basically?

author: Alti
author_rank: Frequent Contributor
timestamp: May 14, 2021, 09:58:07 pm
content: Quote from: SilverSolder on May 14, 2021, 05:00:26 pmNow, lets put that "not so clean diesel" on a trailer pulled by EV.

author: Someone
author_rank: Super Contributor
timestamp: May 14, 2021, 10:49:44 pm
content: Quote from: SilverSolder on May 14, 2021, 05:00:26 pmMobile generator, stationary power station, aircraft, etc, they don't have emissions limits anywhere near as restrictive as motor vehicles so comparisons on fuel use are misleading/flakey. Trying to take the fuel use as some measure of environmental impact is then even more incorrect.

author: james_s
author_rank: Super Contributor
timestamp: May 14, 2021, 11:13:56 pm
content: Quote from: Someone on May 14, 2021, 10:49:44 pmThat's only because there are not very many of them in spaces where people congregate. If there were millions of 737 jetliners rolling through the streets in every city and town around the country, or if every suburban house had a Diesel generator rumbling away all afternoon next to the driveway you can bet there would be much more restrictive emissions limits than there are. We'd be choking on fumes and smog from them the way people were prior to emissions regulations on cars. It's easy to forget how much cleaner cars are now or even 30 years ago than in the early 70s and before. There are vastly more cars on the road now yet the air is not nearly as polluted from them. Getting rid of the lead in gasoline was probably the biggest environmental improvement in my lifetime, tetra-ethyl lead is really nasty stuff and vast quantities of it were spewed out all over the world resulting in measurable lead contamination virtually everywhere on earth.

author: David Hess
author_rank: Super Contributor
timestamp: May 15, 2021, 06:29:57 am
content: Quote from: Someone on May 14, 2021, 10:49:44 pmStates like California have emission rules for portable generators.

author: james_s
author_rank: Super Contributor
timestamp: May 15, 2021, 06:44:15 am
content: Quote from: David Hess on May 15, 2021, 06:29:57 amWell, sort of. It isn't like the emission rules on cars though. My Honda generator was purchased in California by the original owner so it has the special California gas cap that has a charcoal filter in it and a mandated lanyard (which I removed because it got in the way) but otherwise it is identical to the 49 state model. Carbureted engine, no EGR, no catalyst, no oxygen sensor, air injection or anything like that. It would never pass the emissions standards cars have to pass.

author: Someone
author_rank: Super Contributor
timestamp: May 15, 2021, 06:49:14 am
content: Quote from: james_s on May 14, 2021, 11:13:56 pmRead the full quote:Quote from: Someone on May 14, 2021, 02:33:15 amA fundamentally wrong conclusion by picking a flawed comparison and failing to actually account for environmental externatilites.Its neither more efficient or greener.

author: David Hess
author_rank: Super Contributor
timestamp: May 15, 2021, 01:24:23 pm
content: Quote from: Someone on May 15, 2021, 06:49:14 amUsually that is the case though. Lower compression engines are less efficient but lower compression is required to prevent the formation of excessive nitrogen oxides unless these are handled in some other way. The flow restriction from a catalytic converter also lowers efficiency.

author: Marco
author_rank: Super Contributor
timestamp: May 15, 2021, 02:40:24 pm
content: Intuitively I'd say being able to easily just throw an order of magnitude more space at catalytic conversion in a stationary generator than in a car will reduce efficiency impact somewhat. Using consumable based approaches is also less of an issue for a generator being run by people paid to run it instead of our lazy asses who don't want to be bothered with an extra pump.

author: Someone
author_rank: Super Contributor
timestamp: May 15, 2021, 11:31:06 pm
content: Quote from: james_s on May 15, 2021, 06:44:15 amThere are emissions standards for mobile generators (effectively what that unit was), but a) they aren't required in Australia so its unlikely that was the case for the comparison presented, and b) the limits are so much higher per unit of energy/work/whatever metric that its implausible the emissions are similar. Going with same year (2019) emissions limits for Europe:Euro 6 diesel car limits:CO: 0.5g/kmHC+NOx: 0.17 g/kmParticulate load: 0.0045 g/kmParticulates: 6×10^11 /kmEuro V nonroad mobile machinery diesel engine 8-19kW:CO: 6.6g/kWhHC+NOx: 7.5 g/kWhParticulate load: 0.40 g/kWhParticulates: n/aconverting that for their idealised 150wh/km in the best case BMW i3:CO: 1.0 g/kmHC+NOx: 1.1 g/kmParticulate load: 0.06 g/kmSo an order of magnitude worse on pollutants, and 2x on CO.Quote from: David Hess on May 15, 2021, 01:24:23 pmTheoretically, could be possible, but isn't in practice when compared to a car engine which has been pushed to the limits to keep its emissions down (they're trading off all sorts of other parameters to meet the vehicle emissions standards).Quote from: Marco on May 15, 2021, 02:40:24 pmAgain, in theory entirely possible. But not done in practice as there is no incentive to do so.Less efficient use of fuel in a more polluting engine, certainly not greener.Could possibly perhaps be greener in the future if people wanted to, yes. But thats just hollow promises.

author: G7PSK
author_rank: Super Contributor
timestamp: May 23, 2021, 04:30:57 pm
content: A diesel generator plant runs far more efficiently than a traction diesel and burns cleaner due to only having to run at a fixed speed. There emission regulations for stationary diesel engines presently at tier 4https://www.wpowerproducts.com/news/generator-tier-ratings/There are new designs coming to market as well. The Liquid piston engine looks promising at 33% greater efficiency than a conventional ICE unit.https://www.startengine.com/liquidpiston#:~:text=A%20new%20efficient%2C%20lightweight%2C%20and,all%20internal%20combustion%20engines%20today.I for one am not writing off ICE engines in any form for the foreseeable future, heavy electric traction is only viable on rails at present, big trucks and agricultural machines will have to have some form of fuel powered engine for a long time yet unless some invents a battery with a power density equal or greater than that of anything available to date

author: Someone
author_rank: Super Contributor
timestamp: May 23, 2021, 11:41:15 pm
content: Quote from: G7PSK on May 23, 2021, 04:30:57 pmYou make the exact same mistake again, a large stationary engine running at an ideal load could be more fuel efficient, but that is traded off against emissions. Note that the emissions you link to are matching/harmonized with the EU ones I quoted above showing that the limits are extremely lax in comparison to road vehicles. The claim that an electric car powered by a generator is more efficient or green is not true, and has not been shown.Engines can be optimized towards many different goals, cutting emissions almost universally detracts fuel efficiency. The metrics being discussed here are:fuel use per distance travelledpollution per distance travelledReducing one does not imply reducing the other, at an engine level they are often competing requirements/metrics. There are larger stationary engines/power plants with tighter emissions that approach the strict limits of "light vehicles", but they achieve lower fuel efficiency.

author: SilverSolder
author_rank: Super Contributor
timestamp: May 24, 2021, 12:05:55 am
content: Building on @Someone's comment above, it is possible to re-tune pretty much any modern ICE car to give better fuel economy and performance... at the cost of emissions.Basically it works like this: Performance, fuel economy, emissions... Choose any two!

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 24, 2021, 12:27:26 am
content: Yep. And with all that said... although the question may at first look interesting, you have to take a look at the bigger picture.EVs are charged through the electricity grid. Developing a secondary grid just for charging EVs is questionable, and would probably make little sense. I doubt it's going to happen.So... the overall question is (as always) how we are going to generate that much electricity. We'll just need more power plants. Are some of those plants going to be petrol-based? I seriously doubt it. If we take a look at the current worldwide electricity generation, for fossile fuels, coal is by far the largest. After that we have gas (not gasoline), and oil is a very small amount actually. There's a reason for this.Again, I highly doubt dedicated grids just for charging EVs are going to happen, and doubt they would make any sense. Because if petrol-based generators are actually more efficient than other means for generating electricity, why wouldn't we use them already? So the point is completely moot IMHO. While the efficiency compared to ICE *may* be slightly better (although, as said above, it's highly questionable), who in here really thinks we're going to invest in large petrol-based generators for a secondary grid and call that "green"? That doesn't quite add up somehow.

author: james_s
author_rank: Super Contributor
timestamp: May 24, 2021, 05:02:13 am
content: Generators are only going to make sense in specific circumstances. Isolated areas that lack sufficient grid power, and possibly cold climates where the waste heat produced by the engine is not wasted. You can heat your house with engine heat if the engine is stationary, you can't do that engine is in the car.

author: tszaboo
author_rank: Super Contributor
timestamp: May 24, 2021, 07:37:12 am
content: Quote from: james_s on May 24, 2021, 05:02:13 amYou are talking about CHP which makes a ton of sense. AFAIK there was a lot of testing of micro CHP generators, but they were more complicated than regular boilers and inverters, so their reliability was worse.I am a huge advocate of using these technologies combined with Power to gas. Basically using methane as an energy storage and transportation network, instead of electricity directly. Take a petrol station, in the middle of nowhere as an example. Install a large CH4 tank at the back, use micro power plant to generate electricity to charge EVs. Use solar power plant to turn water and CO2 to CH4.

author: G7PSK
author_rank: Super Contributor
timestamp: May 24, 2021, 11:34:29 am
content: Quote from: tszaboo on May 24, 2021, 07:37:12 amCHP makes a lot of sense instead of the heat pumps the UK government is going to force on every one and as for the UK governments idea of pure hydrogen instead of natural gas down the existing gas network do they not know that most materials are porous to hydrogen, there will be a lot of fires. Many hospital's in the UK already run CHP as do sewage works where the gas is produced on site and then run through the CHP unit.

author: Marco
author_rank: Super Contributor
timestamp: May 24, 2021, 03:36:24 pm
content: There's not enough biogas to make a significant difference, those screwing around in the margin projects should be left to the market. They are just a distraction to government ... which loves spreading around all their money screwing around in the margins.Make a plan for megaprojects to do 100%, don't worry about 1% projects. Whether it's nuclear plants, pumped hydro, hydrogen in old gas fields ... whatever, if it ain't TWh scale it's not worth worrying their little heads about.

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 25, 2021, 05:35:05 pm
content: Quote from: james_s on May 24, 2021, 05:02:13 amYes of course. Such generators could have their uses. Just realize that authorities do not care about that. They care about distributing energy for the masses. So that doesn't fit in the big picture, and as it concerns a very small fraction of all uses, efficiency for those cases doesn't matter much in the big picture.

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 26, 2021, 02:39:12 am
content: Quote from: SilverSolder on May 24, 2021, 12:05:55 amLogically, the solution then would be to optimize the engine for fuel economy and emissions, then add an electric drivetrain in parallel if more performance is desired.

author: SilverSolder
author_rank: Super Contributor
timestamp: May 26, 2021, 02:06:48 pm
content: Quote from: NiHaoMike on May 26, 2021, 02:39:12 amThere you go, cracked the secret of the Hybrids.

author: Kleinstein
author_rank: Super Contributor
timestamp: May 26, 2021, 07:30:15 pm
content: The hybrid or petrol based CHP can be OK for the immediate future, but on the long run there would be no affordable petrol to burn. Depending on how serious they take the climate change - the long run may start in some 10-20 years.There may still be petrol left, but likely expensive and in limited quantety (by supply or political limits).Quote from: Marco on May 24, 2021, 03:36:24 pmThere likely will not be a single solution for all - the conditions are too different. Especially with the more fluctuating renewables it helps to have a mix from different sources. A single 100% source is very risky and likely not working well, except for a few places with a clear favorite like solar in some desert regions, wind on some islands or high temerature hydrothermal where available.In the end the current demand is not relevant - the question is what will be available and were. It is easier to more some high energy industries to the source than transporting electricity over long distance.

author: james_s
author_rank: Super Contributor
timestamp: May 26, 2021, 09:11:21 pm
content: Quote from: NiHaoMike on May 26, 2021, 02:39:12 amA car fitting that description exists, it's called a Prius. It has a small Atkinson cycle gasoline engine which is optimized for fuel efficiency at the expense of having lousy low end torque and this is coupled with an electric motor-generator which augments the engine to make the car feel reasonably peppy when one wants to accelerate. Various changes and refinements have been made from one generation to another but the same basic idea is the same - highly efficient ICE in tandem with one or more electric motors.