partial ethanol and full alcohol are not even close.
Close enough. E10 is enough to see most of the issues you will see with pure Ethanol. Most engines just need to run is different fuel maps. ideally you would make other changes (increase the compression ratio), but they are expensive.
Some engines (SAAB, I'm looking at you) will detect knocks and adapt the map on the fly.
It is a sign of the success of the oil industry that this analysis always takes the cost of electricity generation back to the source, but assumes that fuel stations pump from a perfect source of naturally refined/distilled hydrocarbons. It is surprisingly difficult to get numbers on how much oil is used to extract, refine and transport oil. The best I found was this: https://www.speakev.com/threads/energy-required-t…
> It is surprisingly difficult to get numbers on how much oil is used to extract, refine and transport oil. Not to mention the socialized costs of all the wars, military spending and human lives spent to secure stable sources of fossil fuels. If you actually break down the numbers and applied some basic ethics, I doubt fossil fuels have been cost competitive for decades.
We will still have those same wars after EV's. Oil has been a good incentive, but let's face it - the U.S. loves us some wars.
And Uranium-235 about 1GWh/kg EDIT: this is for nuclear fuel enriched to 3% in a normal (not breeder) reactor 35000 MJ per 10g pellet https://whatisnuclear.com/energy-density.html Only a tiny fraction of the total energy is actually used
Whoa so… 100kwh is 40mg! 3grains of sand to run a Tesla https://www.wolframalpha.com/input?i=100kwh%2F%282.5+gwh%2Fk...
Except a lot more is released at once so it will accelerate like a jet engine on every stop sign
How the hell a Chevy Cruze gets 31mpg with a diesel??? A VW Passat TDI will easily get 60+ imperial MPG, I've had it get close to 70 on long runs(that's 50 and 58 American MPG respectively). Are American diesels this inefficient?? Looking at pictures online the Chevy cruze doesn't seem like a bigger/heavier car than a Passat, so what gives??
Here in the Netherlands, we'd translate 31mpg to "1 per 11". One can drive 11km on 1L of fuel. 1 per 11 is a joke. It's associated with heavy petrol cars from the 80s and 90s, before anybody even attempted efficiency. Even my 15 year old diesel car had an efficiency of 1/22. Adjust you driving style and I'd get 1/25. Range: 1000km, with an ordinary sized tank. It seems Americans haven't even started with efficiency,…
What's with these weird, grandiose generalizations I've been seeing about America on this site, based on single data points?
Do you realize that other brands and models exist in the USA? Do you realize Tesla is and American company? Did you even check look into Chevy Cruze's mileage? Here's a guy getting 70mpg in a Chevy Cruze by driving 55mph on the highway. That's 30km/l.
Or we'll just go full circle and gasoline will be available at pharmacies: https://radair.com/blog/2011/11/10/automotive-history-benz/
Wondering… Is it possible to make tiny refineries for say a town or area? So locally produced or is that a environmental nightmare?
It makes orders of magnitude more sense to have one centralized large refinery and then many dispersed holding tanks to distribute fuel. This model may sound familiar.
The big reason for this is thermodynamics. A conventional internal combustion engine car has to convert chemical energy to kinetic energy - the absolute best theoretical efficiency of this might be 70%, but in practice it's more like 30%. Electric cars have to pay the same thermodynamic penalty, but they pay it at the power station (In practice, thanks to renewables, not all the electricity used to charge a car will…
It is a sign of the success of the oil industry that this analysis always takes the cost of electricity generation back to the source, but assumes that fuel stations pump from a perfect source of naturally refined/distilled hydrocarbons. It is surprisingly difficult to get numbers on how much oil is used to extract, refine and transport oil. The best I found was this: https://www.speakev.com/threads/energy-required-t…
> It is a sign of the success of the oil industry that this analysis always takes the cost of electricity generation back to the source, but assumes that fuel stations pump from a perfect source of naturally refined/distilled hydrocarbons.
It's not like renewable energy doesn't take resources/energy to produce as well. It's just borderline impossible to get real numbers because you'd pretty much need perfect information on the supply chains.
Not saying that renewables don't still win in such a comparison.
Oof. Jet engines are 35% efficient, I'd assume electric planes would be double that, does that change the calculation? Naively I'd say we 'only' need 4.5GW?
I feel like the back of the envelope calculation must have slipped a decimal point somewhere. 9GW is approximately 1/4 of the total electrical consumption in the whole of the UK. From memory aviation as a whole is only 2% of global emissions (although it might have an extra forcing effect due to being released directly into the upper atmosphere) where as electricity generation is 20-40% of emissions.
To paint a rough and ready picture, aviation emissions are very heavily weighted towards richer, less populous countries, whereas electricity generation (and particularly fossil fuel generation) is (to a lesser degree) tilted towards where the mass of population is: https://ourworldindata.org/carbon-footprint-flying#:~:text=W... vs https://ourworldindata.org/grapher/carbon-intensity-electric.... Note that the colour axis is a log scale. It's a compounding effect: more people => more energy; poorer => worse emissions and fewer flights per capita.
I thought I must have slipped a power of 10 too somewhere but if I did I can't spot it.
The big reason for this is thermodynamics. A conventional internal combustion engine car has to convert chemical energy to kinetic energy - the absolute best theoretical efficiency of this might be 70%, but in practice it's more like 30%. Electric cars have to pay the same thermodynamic penalty, but they pay it at the power station (In practice, thanks to renewables, not all the electricity used to charge a car will…
Though that makes me think that hybrids have a real future. Or hydrogen fuel cells. Anything that doesn't require charging directly from the grid all the time, because although parts of the USA and Norway are ready for that, it's very tricky to get right globally. Maybe hybrids like the Prius get to be so efficient that such cars will have a truly negligible impact on global warming.
I’ve stayed in places of the grid before in Asia. No gas stations for miles around, but they would have solar panels or a water wheel out back for electricity, if not very reliable. I imagine EVs would be even better for such places, just charge them via some local renewable, the battery deals with the unreliability of the source.
I just realized how much energy efficiency is being squeezed out of a Tesla. It's incredible. A normal diesel fueled sedan such as the Chevy Cruze diesel runs at about 31mpg, which is 13.2 km/l or 15.3 km/kg. Diesel has a mind-boggling 12700 Wh/kg energy density[1], which translates to an efficiency of ~827 Wh/km for the Chevy. By contrast, the Tesla Model S, has a ~540 kg battery[2]. At 272 Wh/kg (from the posted ar…
Relative efficiencies also explain why city/highway efficiency is inverted between EV & ICE. Gasoline is rather energy dense, but the ICE is rather wasteful. There is a certain base load of energy being generated by an ICE engine, regardless of if you are moving or how slow you go. This is why carmakers experimented with things like rapid stop/start engines, regen batteries&motors, etc. ICE becomes more efficient as…
Maximum heating power in my 2015 Tesla Model S 70D is 6 kW. Travelling for 100 km at 100 km/h costs about 25 kWh. I drive in shirtsleeves and barefoot in the Norwegian mountains at -20⁰C and the heater doesn't seem to be running hard. So unless you are traveling in severe arctic conditions the heater really isn't more than a few percent of the load.
Teslabjørn has a video where he turned his Model X into a sauna getting 40⁰C inside while it was -10⁰C outside.
It is a sign of the success of the oil industry that this analysis always takes the cost of electricity generation back to the source, but assumes that fuel stations pump from a perfect source of naturally refined/distilled hydrocarbons. It is surprisingly difficult to get numbers on how much oil is used to extract, refine and transport oil. The best I found was this: https://www.speakev.com/threads/energy-required-t…
The average energy required to extract fossil fuel energy is constantly increasing, as we go after harder and harder to get oil. It used to be easy enough nobody really paid attention to that, but now people talk about "EROI" or energy return on investment, to track the net energy gain of an operation.
Most people still have that simplified view that you just have an oil well and just pump it up. In the US, a significant portion is extracted with fracking, an environmentally pretty terrible method for extraction.