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Upstream carbon emissions
- Thread starter LukeT
- Start date
vitesse
Active Member
My understanding is that David MacKay basically exposed the reality that the prospects for green energy creation were overly-optimistic and the benefits of reduction in energy consumption were too easily overlooked. On top of that there are plenty of wise words not being backed up by the necessary action required by the people who utter those words. All this is backed up with pretty solid science and statistical evidence and reasoning.
Lasairfion
Member
This is well worth a watch to understand how global warming actually works. The efficacy of a greenhouse gas like CO2 and its concentration matters, but only inasmuch as it opens the gateway to the real problem greenhouse gas, which is water vapour. This video explains the relationship very well.
As an aside, one of the worst gases is a man-made compound called Sulfur Hexaflouride. Used in Nike Air shoes up until 2006, it is 24,000 times more effective at trapping energy than CO2 and has a life span of 800 to 3,200 years before dissipating. Luckily there isn't much of it about.
vitesse
Active Member
I am not an expert but I read reports indicating that the cost of wind energy, particularly off-shore (I'm not against on-shore by the way) has dropped per kWh produced dramatically - maybe exceeding market expectations. This can only be because of market demand (in other words the more production is purchased the more incentive to invest in more efficient and greater production).
I can understand the basic logic in suggesting that signing up to a green energy supplier only pushes the dirty energy to a different consumer but I do believe this seriously undervalues the motivation for the electricity generation industry to compete for increasingly cheaper and greener electricity generation. Surely, this will get to a point where green energy is cheaper than dirty energy and nobody should be paying a premium for that!
Jason71
Well-Known Member
There is not much out there but its increasing and the main use is in Electrical installations as a fire retardant for electrical fires. Electrical installations like wind and solar farms both ironically and sadly.
Interesting thread..
The only thing which I could not understand and will probably will tip the balance towards EV further in the future is Carbon Intensity of Power in Battery = 230. What is your source for this figure?
I can see a big range for this figure on internet from as low as 55 to around 200.
According to here,
Automotive lithium-ion batteries provide an opportunity for reuse in stationary storage applications after their vehicle use phase. This can reduce the battery greenhouse gas emissions attributable to the vehicle on a per-kilometer basis by 42%.
The only thing which I could not understand and will probably will tip the balance towards EV further in the future is Carbon Intensity of Power in Battery = 230. What is your source for this figure?
I can see a big range for this figure on internet from as low as 55 to around 200.
According to here,
Automotive lithium-ion batteries provide an opportunity for reuse in stationary storage applications after their vehicle use phase. This can reduce the battery greenhouse gas emissions attributable to the vehicle on a per-kilometer basis by 42%.
WannabeOwner
Well-Known Member
Yes, his "book" shows scenarios like "covering all available usable land with windmills" and whether that was realistically doable / what it would cost ... and that all that would still not be enough ... but there have been some subsequent breakthroughs; his estimate of North Sea Wind, and the cost of deployment, have been beaten by a wide margin. Windmills on land seem to have met huge resistance from planners (and probably NIMBYs too ...) which wasn't something expected back then (back then it look prohibitively expensive to bring power in from miles out to Sea, compared to "just hooking a land based windmill up to nearby grid")
I think it is largely the technical breakthroughs, reducing the cost. Some political will to "do something " may well be helping too, but even without subsidy I think Wind install is already cheaper than other more conventional sources. just the darn things won't reliably produce 24/7/365
The size of the blades, and how to get them out to sea, and physically attached when you get there, must have been a challenge and, at the outset, might well have seemed "impossible".
Also how to anchor the tower to the seabed. I believe they now stand them (hollow tube) upright and then pump the seawater out, creating a vacuum, and that just "sucks" the tube into the seabed. A lot easier than the building inspector insisting on 3M of concrete foundations :
I think it does one other thing which is that the customer(s) departing from Dirty Energy Producer puts pressure on them to provide Green Energy, or lose all their customers! more especially if there is no price penalty moving away.
My 230 is, rightly or wrongly, after I apply some estimates for energy lost along the way:
Carbon intensity of UK Grid power 180gCO2/kWh UK published figure 2018 (which should steadily reduce over time but which I haven't yet confirmed is "life-cycle" or power station emissions)
8% grid losses assumed, so 180/92% = 192gCO2/kWh at the house meter (I'm assuming the 180 is at the power station and grid losses should be considered on top; it's an assumption - I don't know this to be the case)
15% charging losses assumed, so 192/85% = 230gCO2/kWh useable charge in the battery.
I got 15% from my Teslafi experience to date - I'm hoping this will reduce once I start charging at higher currents, but equally I've been trying to take care in my analysis not to overestimate the benefit of EV so I'm happy to see a bit of conservatism in there.
The manufacturing part of these numbers is quite interesting to illustrate. Manufacturing of EV is a big emitter, but it's not a particularly big emitter when compared with driving an ICE (year 1 is manufacture, year 2 is first year of use, 12k miles p.a. is assumed in this graph and I still haven't included any upstream emissions except 6kWh of gas burned equivalent at the refinery):
cezdoc
Member
When you purchase petrol/diesel you can't do much about the associated emissions per litre (it might be that some suppliers are better than others & admittedly I have never looked at this - seems a bit like deckchairs on the Titanic!). However the same is not true of charging an electric car: the end user can reduce the carbon intensity of their power source by making simple choices with little inconvenience/cost. So it would be worth quoting grid average _plus_ an upside case assuming some good habits by the end user. These would be:
1. Use a 100% renewable energy supplier
2. Use public charging networks supplied by 100% renewable sources. Two examples are the Supercharger network and Instavolt.
3. Charge off peak
You could add in use of domestic solar but that requires a bit more investment & the ability to regularly charge at home during the day so arguably not such a simple choice.
Option 3 mitigates the "if I use renewables someone else's supply gets dirtier to compensate" argument. Personally I believe the market works & in addition I use a supplier who only offer renewable tariffs (100% wind), but you can also look at the grid average at the time you're charging. Over the past year I've tracked the grid carbon intensity using the GridCarbon app and often the average has been below 180 gCO2/kWh during a charge session - sometimes below 100. But interestingly the average did work out around 180 over the year. I doubt these are life cycle figures as wind and solar, for example, are assumed to emit no CO2.
There are tools like the one at carbonintensity.org.uk which forecast grid carbon intensity to help you decide when to plug in if you want to minimise the carbon intensity of the overall power supplied.
If you accept that the renewable electricity market works then you could argue that you can charge up EVs with 0 gCO2/kWh electricity (with a bit of life cycle emissions on top for construction etc.). Stick that in your tailpipe, ICE cars!
My own figures suggest domestic charging at 10A is about 77% efficient and 32A is 85% efficient but I don't know how Teslafi do their calculations. So 15% might be as good as it gets for domestic charging unless you have a three phase supply.
MrBadger
Badger out
Don't get me started on the Lensbury Club in Teddington preventing a community hydro scheme being built at Teddington weir as it would be too noisy for their guests. I guess they never listened to how noisy the weir is in its own right, would certainly drown out the noise of any hydro scheme most of the time. I cycled over Teddington lock very frequently as a teenager - perfect hydro conditions.
Did I mention anything about Lensbury being a Shell subsidiary
vitesse
Active Member
Coming to think of it, an ICE during its lifecycle could consume over 15 tons of petrol. That's just the refined end product that goes into the car. How many more tons needs energy to be pumped out of the ground, pumped to storage facilities, pumped or shipped to the refinery, heated, condensed and re-heated to crack the hydrocarbons during the refining process, during which considerable quantities of gaseous waste is burned, then the end-products need to be pumped to storage, then to transportation and then transported on to petrol stations. Even then, it has to be pumped into your car. I wonder how much electricity petrol stations consume?
I guess it's worth pointing out that electric car batteries are very heavy and that battery weight is unchanging and probably weighs more than ten times that of a full tank of petrol. But electric motor and regen efficiency - plus the lack of weight of an engine block and combustion head and gear weigh in favour of electric cars.
I guess it's worth pointing out that electric car batteries are very heavy and that battery weight is unchanging and probably weighs more than ten times that of a full tank of petrol. But electric motor and regen efficiency - plus the lack of weight of an engine block and combustion head and gear weigh in favour of electric cars.
Don't get me started on the Lensbury Club in Teddington preventing a community hydro scheme being built at Teddington weir as it would be too noisy for their guests. I guess they never listened to how noisy the weir is in its own right, would certainly drown out the noise of any hydro scheme most of the time. I cycled over Teddington lock very frequently as a teenager - perfect hydro conditions.
Did I mention anything about Lensbury being a Shell subsidiary
So so many examples of this kind of crap stopping renewables schemes.
I don't have any figures except Teslafi's charge efficiency percentage which comes from their kWh used vs added numbers. I guess the car calculates energy in at the charge plug from amps at that point and separately start and end SoC. I'm missing anything lost between domestic meter and that point. How have you got your figures?
This, except the refining bit, is exactly a summary of the gap in my analysis and it seems to me that information is hard to come by!
If per litre produced this activity causes emissions of 500g, which would be 2/3rds of the refining figure and 1/5th of the tailpipe emissions figure, the lifetime emissions of my example ICE would be 3x my example EV. If that's 2,000g then the multiple becomes 4x.
These points should all be contained in the resulting Wh/mile and mpg.
cezdoc
Member
I calculate efficiency by comparing Wh/mi figures: how much energy the car uses to travel one Typical Mile / how much energy was supplied to add one Typical Mile (TM). Provided I use figures for single trips with no stops (or brief stops with no heating/ac while parked) I get consistent figures.
Energy supplied to add one TM = current x voltage x time while charging / TM added
Current and voltage are reported in the car and on the app. My supply is 32A (UMC + commando socket) and the voltage varies a bit but is usually around 230 V (it drops a few V when the charging starts then settles down). So energy in for me = ~7.36 kWh per hour. I usually schedule charging overnight so I get the TM added from the app notifications.
In my case I've calculated 376 Wh/mi on a 10A 3 pin socket and 338 Wh/mi on the commando socket.
Energy used to travel one TM - this is a fixed number for each car model. Calculating it is just a case of noting the battery range before setting off on a longish trip, then noting the trip stats at the end. For my MS70 RWD it works out at 288 Wh/mi (i.e. if I managed to average that on a 100 mile trip, the battery range would drop exactly 100 Typical Miles)
TeslaFi probably does all the above automatically (and has the benefit of regularly polling the data so will pick up variations in the voltage supply, for example).
vitesse
Active Member
The TeslaFi figures for kWh 'used' (as opposed to the smaller 'added' figures) during charging correlate well with my smartmeter log.
I know it's difficult to work out background consumption but I'm hovering around a daily 5kWh average, which would be MCU, climate control (have been warming the car for my wife in the mornings), third party dash cam, idling, etc. The car is sleeping well - over half the day.
I know it's difficult to work out background consumption but I'm hovering around a daily 5kWh average, which would be MCU, climate control (have been warming the car for my wife in the mornings), third party dash cam, idling, etc. The car is sleeping well - over half the day.
MrBadger
Badger out
5kWh is huge amount if it’s not being used for charging.
That’s over half my house daily consumption and that’s before it’s offset with solar. I average just over 6kWh/day import and that’s with electric cooking.
That’s over half my house daily consumption and that’s before it’s offset with solar. I average just over 6kWh/day import and that’s with electric cooking.
This is nice to know. So nothing much in the way of other missing losses along the way.
5kWh sounds huge. I wonder what energy it would take to warm the car up on a cold day? Could that alone account for the number?
For other end of the scale usage I found roughly 0.7kWh was used by a car with no user input at all. Left to sleep as it wants, not driven etc. (we were away and left it unplugged). No accuracy to that though so it could be wrong - a few months down the line maybe I can find out from Teslafi the amount of energy used in everything except for driving and average that out - but this number has to change a lot before it affects total car energy use by a material percentage anyway. My analysis above is neither very granular nor very accurate! I should probably increase the daily non-driving use consumption from this though because in daily use its not sleeping the same and there is often going to be some HVAC use outside of the defined journey.
However it's also very user-specific. I tend to leave the car alone until I am going to drive it, then I get in and go. I'm not really bothered by warming/cooling it first and so my only regular application of this would be to reduce range loss by using home power for it rather than sacrificing range. So I put this activity into a bit of a different bracket of user choosing to use electricity for some extra comfort, or playing games with the toy, rather than driving. I've never been one to idle an ICE on a cold morning before driving it, which just seems wrong to me.
I also find range mode is a decent approximation to my normal use of car climate control. I want it to do very little within a reasonably wide comfort band and only really do much heating or cooling when internal temp is quite far wrong. Maybe I'm just insensitive!
Use of home renewables or night time charging is similarly user specific so it's kind of an "upside case" - with the means and the inclination big steps in reducing carbon impact can be made here but it doesn't happen on its own. Almost all of our charging is 11pm-7am but grid, so if 180gCO2/kWh is annual average then our reality might be say 20-40% below that. Transformational on the EV vs ICE numbers and even with the inclination you can't do it on an ICE, but it's still about the user.
vitesse
Active Member
@LukeT Just to clarify, that's 5kWh on a typical day, including driving - so my best attempt to work out the difference between the energy used by the motor and the total energy used during the charging process. Some of that is charging inefficiency if course.
I could be, in effect, attributing things incorrectly.
Earlier this morning during charging there was 14.4kWh consumed by the charging process. That's a Teslafi figure but it tallies with my smart meter log. 12.86 kWh was added to the battery. That's a difference of 1.54kWh - which we can attribute to charging inefficiency.
I'm currently charging the car every night back to 70%.
Teslafi reported that during the previous day 11.5kWh was used while driving, so that's a difference of almost 3 kWh compared to the 14.4kWh consumed during charging. So about 1.5kWh was used elsewhere during the day.
In that day 31.9 miles was driven (my wife's commute), so that's 360 Wh/mile from 11.5kWh (Teslafi) of battery used. My understanding is that this figure is only computed while the car is being driven (is that right)?
So yesterday it was about 3kWh of charging inefficiency and other losses but I'm, maybe conservatively, thinking that will average to 5kWh per day over a year taking into account winter. I've seen the daily difference reach 4kWh already.
Teslafi says the car slept for 14 hours and was on idle for 7 hours. Driving was 1 hour and 20 minutes. Teslafi says idling and sleep loss was 1.1kWh for that day.
I could be, in effect, attributing things incorrectly.
Earlier this morning during charging there was 14.4kWh consumed by the charging process. That's a Teslafi figure but it tallies with my smart meter log. 12.86 kWh was added to the battery. That's a difference of 1.54kWh - which we can attribute to charging inefficiency.
I'm currently charging the car every night back to 70%.
Teslafi reported that during the previous day 11.5kWh was used while driving, so that's a difference of almost 3 kWh compared to the 14.4kWh consumed during charging. So about 1.5kWh was used elsewhere during the day.
In that day 31.9 miles was driven (my wife's commute), so that's 360 Wh/mile from 11.5kWh (Teslafi) of battery used. My understanding is that this figure is only computed while the car is being driven (is that right)?
So yesterday it was about 3kWh of charging inefficiency and other losses but I'm, maybe conservatively, thinking that will average to 5kWh per day over a year taking into account winter. I've seen the daily difference reach 4kWh already.
Teslafi says the car slept for 14 hours and was on idle for 7 hours. Driving was 1 hour and 20 minutes. Teslafi says idling and sleep loss was 1.1kWh for that day.
I think we're talking about similar numbers then. I attributed some of these kWh as charging loss then a smaller amount to daily vampire drain then the rest is turned to miles at the Wh/mile in the car trip info. You calculate a Wh/mile based on charge put in and miles out, so that'll be higher than mine. Our Model S averages about 320Wh/mile on the trip computer so far.
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vitesse
Active Member
@LukeT The car wasn't driven yesterday and TeslaFi reckons 1.3kWh has been used in the last 35 hours. The range has dropped by 1% since the end of the last charge (32 hours approx) or a bit more precisely 2.8 mile (Typical range). I do have a Viofo dual dash cam running 24 hours and the app did wake the car a couple of times (my fault ). The car appears to have slept around 66% of the time.
). The car appears to have slept around 66% of the time.