Peter wrote:
reckon a normal car at 50mph needs about 30kW.
My Kia E-Niro, which I guess is a “normal car”, will use about 12 kW at 50 mph. According to the car’s own range computation, turning on the AC will reduce range by about 5%
If the ‘normal’ car will do say 140 mph on 180 HP the parasite aero drag (which dominates for cars at high speed) at 50 mph will absorb on the order of 10 HP. Add another 10 HP to overcome rolling resistance (power proportional to speed) and you’re at 20 HP or 15 kW.
Peter wrote:
Does anyone have an estimate of how much power aircon uses?
It sucks a lot of battery load. Without aircon typical consumption of my BEV is about 15 kWh per 100 km (that is, by the way, quite low in comparison), and with aircon in 40 °C OAT goes up to 22 kWh / 100 km, so up to 50% more.
@Airborne_Again, thanks for your reaction. I think it confirms what I wrote – it depends on the chosen battle.
Airborne_Again wrote:
for each individual it depends very much on where you live.
Agreed. Insignificant from the global point of view. Beneficial in the “Mission profile” category.
Airborne_Again wrote:
EVs have the potential of (economically) using entirely CO2-free energy sources.
Economy depends on subsidies, and if you mention CO2, then we talk about a global problem.
Focusing on electric cars has zero chance to change anything. Cars are just energy consuming devices, and the energy comes from burning fossil fuels, one way or another.
If we want to make a change, we shall stop subsidizing consumption (I know, not easy, too political) and invest in creation. We need to create clean sources of energy. And (also difficult, also political), we must promote science and technology over ideology.
Is wind and solar the holy grail?
What we need are clean sources for the baseload power. We need our companies to produce value days and nights, in windy as well as still situations. We need a light anytime we turn on a switch, regardless of a weather forecast.
When we look at the windmills or solar farms, we have to see a gas power plant behind each of them. I do not know if the cost of these power plants is calculated into the economic studies of the renewables, but they are there. Why gas? Because these are quick start power plants. While it takes 24 hours or so to get the coal power plant up to speed, nuclear probably takes weeks, gas power plant is running within one hour. They are started anytime the wind stops blowing and grid needs power. So, entirely CO2-free source could be rare, perhaps solar cells at the rooftop of the house, or a country where 95% of energy comes from hydropower. As such these are exceptions, not solving the global situation.
So, we must invest in different sources, and this is the key global challenge.
I do not care about EVs. I just want my money to be invested in making something better and not subsidize a variant of the same that is just different.
“There’s a hole in my bucket dear Pavel dear Pavel ….. with what shall I fix it dear Pavel🙂”
The hole this time has been dug by one V. Putin.
We have a shortage of gas to power the turbines you talk about.
Scientists and engineers everywhere still search for the holy grail. In the meantime EVs will make cities cleaner and reduce the increasing number of asthma cases in children walking to school in those cities because petrol prices are too high.
If en masse EVs can reduce global CO2 levels, so much the better. They of course are not the only pollutants from ICEs.
Sorry @gallois but he’s right. EVs don’t reduce emissions, they just move them somewhere else.
Frankly, if you’re going to consume energy driving a car then why shouldn’t you suffer the emissions locally? Why should you be allowed to shift it elsewhere, to affect people who happen to live near a powerplant?
@ Graham that was the point I was making. If you note I shifted the emphasis to childhood asthma in cities, which is a major problem nowadays in some cities. I did not mention the climate change issue other than as a possible side advantage. Which it is because ICEs ticking over in traffic still pollute whereas an EV does not. Yes I know that modern cars cut engine when sitting for a while but only when the engine has been warmed up.
Moving the pollution elsewhere, well only some of that pollution will be moved.
But it might be enough to reduce asthma, and why should children walking to school suffer so that you can drive around the Elephant and Castle in an ICE vehicle.
As I keep repeating “there is a hole in my bucket” and how are you going to fix it in both the long and the short term?
Graham wrote:
Sorry @ gallois but he’s right. EVs don’t reduce emissions, they just move them somewhere else.Frankly, if you’re going to consume energy driving a car then why shouldn’t you suffer the emissions locally? Why should you be allowed to shift it elsewhere, to affect people who happen to live near a powerplant?
Sorry, @Graham, I’d probably disagree – producing electricity at a power station is going to be always more efficient.
Also, you could produce electricity using different methods, and so you might be able to use clean(-er) methods in the future.
Another reason to promote EVs threrefore is to shift the “end-user devices” from ICE to EV now – that way when we can produce clean electricity in the future, the switch is going to be much quicker. It takes about forever move most people to EV.
Saying all that, I have to admit that I’m a big proponent of not switch NOW for everyone, but do it gradually and only AFTER their present vehicle is no longer repairable – in the end the production of a new vehicle will emit a lot of CO2!
gallois wrote:
But it might be enough to reduce asthma, and why should children walking to school suffer so that you can drive around the Elephant and Castle in an ICE vehicle.
I would say the solution to that is not to drive cars (of any sort) in cities, which is unnecessary anyway and I don’t really understand why people do it.
I agree with you don’t drive cars in cities
But what about delivery vans, people coming to collect heavy shopping, buses, and lorries?
Some cities have a congestion charge, others monitor the number of people in a vehicle. On days when pollution is likely to be high Paris only allows odd numbered vehicles one day and even the next. So some have 2 cars and switch day to day. And what about city residents? Should they have to forego cars altogether? Or should they move to the country?
