premmington
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willie.macleod
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Your quote "My 100mpg 125cc motorbike is not as efficient as my Leaf".
I got a 108cc Honda AFS110 wave. Really shocked me the above.
I don't disbelieve you - but I would have never have thought that.
I'll say this for Honda, their newest CB125F is another step up - it is supposedly a true 150mpg, so I wouldn't beat that with the Leaf (if I am travelling 1 up and have no cargo!)
Your AFS is probably on par with the Leaf, I'd have thought it would do a bit more than 100mpg?
premmington
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The AFS - will do (and I have checked). About 120mpg - dragging me about - the full 100kg fat boy.
Most of the journeys I do - are short and thru housing estates and town roads. Thru the gears mostly.
I would think on a level run with a "skinny" person on it - with no hills and no wind with tyres pumped up/chain adjusted and oiled - it may even hit near 150mpg.
AFS is Euro3 with a CAT. When you take the plug out - you can see how well it meters the fuel into it. True evolution of the C90.
willie.macleod
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I appreciate what you are saying and I'm sure we will agree on many matters, however I can't let the 78% charging efficiency figure go. That can be disproved very quickly and easily by those of us who meter our EVs energy usage both at that wall and in the car. To get a figure that low you are looking at either a level 1 EVSE using 120v charging at ~10A, something nobody in this country does or you are using the figures for a Renault Zoe which has a particularly interesting charger design which helpfully allows it to pull 22kWh from widely available 3 phase charging posts as it incorporates the motor windings in its design at the cost of poor single phase charging efficiency. Your average home charger is a 240V 7kWh unit and that should get an efficiency of around 90% in most EVs.
Mr Fro
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I'm sure you are right in what you're saying about your own circumstances however, you are a very small data set.
When you consider large the national situation then the situation is different. Bear in mind I've not looked at the research for a year so it'll be a year bit I recall charging efficiencies from ~ 50 - ~90% with the average being ~78%. Also, how are you measuring your efficiency? Is it what the charger tells you or are you measuring consumption before the charger and in the car?
Anyway, I'll dig out my paper today to give a better response to you and @daleyd .
RaceDiagnostics
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Surely chargers must be highly efficient, greater than 90%, or they would melt from the heat generated.
They are all in effect switch mode power supplies which are very efficient.
The inefficiency is manifested in how that energy is stored and deployed once it's in the car.
They are all in effect switch mode power supplies which are very efficient.
The inefficiency is manifested in how that energy is stored and deployed once it's in the car.
atomant48
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It’s an interesting area this efficiency. I’ve never thought about it but I’d be pretty upset if 20% of the diesel I paid for went out onto the forecourt. That said I suspect the measurement of the efficiency is subjective - for example my EV does a lot of things in the background particularly while it’s charging so it might not be so much a case of watts in vs watts in the battery?
Munkul
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What about the 50-60% of the of the diesel that you paid for which goes straight into the sky while you're trying to get it to push you along?
I've always been operating on older and more cynical figures for ICE vs electric, but the last few pages have opened my eyes a bit to be honest. I had NOT realised how supendously efficient per KW an electric car can be when you work it out in KWh per mile (or miles per KWh which I didn't think was possible!)
Still limited on storage capacity though. That's my sticking point.
Gareth J
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I asked previously but can't recall if you mentioned it or not, did you also factor in losses for diesel/fuel from well to tank as well as the inefficiencies associated with filling a battery vehicle?
For diesel, it's about an extra 0.2MJ/MJ(final).
Mr Fro
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Extracts from paper:
Assuming the average actual real-world fuel economy of petrol ICEV as 35.94 miles/gallon and diesel ICEV as 42.93 miles/gallon (Sprintmonitor.de, 2021). From this the power used per unit distance can be calculated:
As of the January 2021, there were 56 commercially available fully electric vehicles . The average manufacturer published energy consumption of these is 173 Wh/km and 36.9 gCO2/km:
Experimental data has been produced showing charger efficiency from 49% to 77% (Kieldsen, et al., 2016) and 85.7% (Sears, et al., 2014). This is from the plug to the car.
The authors attribute these figures to value engineering of charging equipment to create readily affordable units rather than those capable of high efficiency. Further to this, Sears et al. state that “Under-dimensioned components cause higher heat dissipation that makes cooling necessary, which is an additional power consumption” meaning that in order to optimise charging efficiency, it is necessary to correctly specify components and software to reduce energy losses.
Sears et at. also states “A power converter with an efficiency of 95 % have a decrease in efficiency of 10 % when operating at half the nominal power”. It is apparent that in order to be able to advertise minimal charging duration, it is necessary to have a high charging capacity i.e.,43kW (63A, 400V) “rapid chargers”. The availability of these charging points is relatively low with only 21.3% of publicly available charging points being able to support ≥63A (Department for Transport, 2021_h). Thus, the majority of charging that will take place, especially for those who charge at home using a standard 13, 16 or 32 amp connection, will incur significant charging losses due to being below the designed peak efficiency of the charger.
If the experimentally derived charger efficiency data are applied to the manufacturer energy consumption figures, the energy usage “from the grid” can be calculated:
Furthermore, the major source of electricity generation in the UK is from burning fossil fuels, namely oil, gas and coal (Department for Business, Energy & Industrial Strategy, 2020_a) (Figure 5). The thermal efficiencies of these generating plant are shown in Figure 6. When the thermal efficiency data are normalised to generation source data, the net efficiency of UK generating plant equates to 43.29%. The rest of the fuel energy is lost to conversion, transmission and distribution. (Digest of United Kingdon Energy Statistics (DUKES), 2020_b).
The total net efficiency for all electricity sources (including renewables) is 45.85%. Factoring the conversion efficiency from primary source i.e., fuel to plug, the net power usage for EV can be calculated:
Given that EV energy consumption data are gathered from manufacturer published test procedures such as the WLTP rather than real-world driving scenarios, it is reasonable to use the same data for ICEV vehicles which show 50.5 mpg for petrol ICEV and 57.9 mpg for diesel ICE (The International Council on Clean Transportation, 2018) and thus, 526.2 Wh/km and 503.92 Wh/km respectively. It is therefore immediately apparent that even in the best case of high charger efficiency, EV are only marginally more energy efficient per unit distance than diesel ICEV when the primary energy source is considered. Note that for this example, the energy required to move the primary fuel to it’s destination of use e.g. electricity plant or petrol station is not considered in the calculations, nor are the energy requirements of building plant and vehicles as they are outside the scope of this research.
I then go on to outline different methodologies of waste energy recovery including testing and evaluation procedures and apply the theoretical (yet realistic) outcome to a theoretical diesel engined car. I then calculate the effect of these technologies on the average power requirements to move it. RB = Regenerative Braking, EER = Exhaust Energy Recovery.
I then compare the power consumption of the "best case" for ICE + waste energy capture against the average EV manufacturer data, charger loss normalised data and calculated "primary source" data.
We see that once primary fuel for electricity generation and charger losses are taken in to account, that both urban and extra urban diesel hybrid models are favourable in terms of power consumption.
Anyway, that's about the nub of it. Apologies if it's a bit disjointed as I've just snipped out the top level stuff.
Interesting what you posted about energy losses @Gareth J . I've not read the report but I imagine that 20% loss isn't unreasonable. It would be interesting to see where these losses occur and how they impact the net power consumption of ICE and EV.
Edit: I don't seem to be able to delete the three images above (repeats) so I've just made them really small.
Assuming the average actual real-world fuel economy of petrol ICEV as 35.94 miles/gallon and diesel ICEV as 42.93 miles/gallon (Sprintmonitor.de, 2021). From this the power used per unit distance can be calculated:
As of the January 2021, there were 56 commercially available fully electric vehicles . The average manufacturer published energy consumption of these is 173 Wh/km and 36.9 gCO2/km:
Experimental data has been produced showing charger efficiency from 49% to 77% (Kieldsen, et al., 2016) and 85.7% (Sears, et al., 2014). This is from the plug to the car.
The authors attribute these figures to value engineering of charging equipment to create readily affordable units rather than those capable of high efficiency. Further to this, Sears et al. state that “Under-dimensioned components cause higher heat dissipation that makes cooling necessary, which is an additional power consumption” meaning that in order to optimise charging efficiency, it is necessary to correctly specify components and software to reduce energy losses.
Sears et at. also states “A power converter with an efficiency of 95 % have a decrease in efficiency of 10 % when operating at half the nominal power”. It is apparent that in order to be able to advertise minimal charging duration, it is necessary to have a high charging capacity i.e.,43kW (63A, 400V) “rapid chargers”. The availability of these charging points is relatively low with only 21.3% of publicly available charging points being able to support ≥63A (Department for Transport, 2021_h). Thus, the majority of charging that will take place, especially for those who charge at home using a standard 13, 16 or 32 amp connection, will incur significant charging losses due to being below the designed peak efficiency of the charger.
If the experimentally derived charger efficiency data are applied to the manufacturer energy consumption figures, the energy usage “from the grid” can be calculated:
Furthermore, the major source of electricity generation in the UK is from burning fossil fuels, namely oil, gas and coal (Department for Business, Energy & Industrial Strategy, 2020_a) (Figure 5). The thermal efficiencies of these generating plant are shown in Figure 6. When the thermal efficiency data are normalised to generation source data, the net efficiency of UK generating plant equates to 43.29%. The rest of the fuel energy is lost to conversion, transmission and distribution. (Digest of United Kingdon Energy Statistics (DUKES), 2020_b).
The total net efficiency for all electricity sources (including renewables) is 45.85%. Factoring the conversion efficiency from primary source i.e., fuel to plug, the net power usage for EV can be calculated:
Given that EV energy consumption data are gathered from manufacturer published test procedures such as the WLTP rather than real-world driving scenarios, it is reasonable to use the same data for ICEV vehicles which show 50.5 mpg for petrol ICEV and 57.9 mpg for diesel ICE (The International Council on Clean Transportation, 2018) and thus, 526.2 Wh/km and 503.92 Wh/km respectively. It is therefore immediately apparent that even in the best case of high charger efficiency, EV are only marginally more energy efficient per unit distance than diesel ICEV when the primary energy source is considered. Note that for this example, the energy required to move the primary fuel to it’s destination of use e.g. electricity plant or petrol station is not considered in the calculations, nor are the energy requirements of building plant and vehicles as they are outside the scope of this research.
I then go on to outline different methodologies of waste energy recovery including testing and evaluation procedures and apply the theoretical (yet realistic) outcome to a theoretical diesel engined car. I then calculate the effect of these technologies on the average power requirements to move it. RB = Regenerative Braking, EER = Exhaust Energy Recovery.
I then compare the power consumption of the "best case" for ICE + waste energy capture against the average EV manufacturer data, charger loss normalised data and calculated "primary source" data.
We see that once primary fuel for electricity generation and charger losses are taken in to account, that both urban and extra urban diesel hybrid models are favourable in terms of power consumption.
Anyway, that's about the nub of it. Apologies if it's a bit disjointed as I've just snipped out the top level stuff.
Interesting what you posted about energy losses @Gareth J . I've not read the report but I imagine that 20% loss isn't unreasonable. It would be interesting to see where these losses occur and how they impact the net power consumption of ICE and EV.
Edit: I don't seem to be able to delete the three images above (repeats) so I've just made them really small.
Gareth J
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My point being, that you seem to have accounted for a lot of those losses when looking at BEVs, but not included them for Petrol/Diesel fuel. The colours of the charts give rough breakdowns of energy expendatures. The most energy intensive listed as "production and conditioning at source" (I read that as getting the oil out and leaving the guff behind) and "transforming near market" (I read that as refining).
The diy chain Leroy Merlin have been offering 350w panels at 150 euros here. There's also a place in the UK called (I think) Bimble Solar.
julianthegypsy
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Bimble, I believe, do second hand panels. They do have an excellent reputation among the off grid community and I see them recommended frequently. They may do new panels too, I haven't checked their website for ages.
Gwill
I am seriously considering solar for my place in Portugal.
The UK though is probably one of the worst places in the World to have it - especially Wales.
Even Canada is better than Wales.
People forget just how far North we are. London is further North than any city in Canada!
They will work on cloudy days but efficiency drops off massively.
A big Teso in Swansea has a huge array on the roof. In sunshine it maxes out at 40kw. On a dull day of typical Welsh weather it drops down to around 800w.
Scotland would be just as bad.
Mr Fro
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I understand your point and I agree with you. If 56% of our electricity comes from fossil then it incurrs the same ~ 20% processing cost as petrol & diesel which is why I think it would be interesting to apply that factor to the data I've already analysed.
Back of a fag packet would give something in the order of 546Wh/km for EV and 605Wh/km for standard diesel.
Hood
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Depends where in Scotland, here on the Angus coast we have little rain in comparison to most places and in Summer we get up to almost 18hrs of daylight peak. Winter not so good as although still usually clearish skies the daylight hours drop to about 61/2-7 hrs
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