Tesla Roadster

[hurril]

Out come the emoticons. And on a "high-brow technical forum," no less.

...saying that EV:s is a liberal toshfest...

TC was commenting on the zero-emissions fallacy, not EVs generally. You've misquoted him.

...and someone else dropping an irrelevant diagram from a dodgy source...

The composition of a grid's power sources determine its emissions. The diagram shows how grids with a mix of renewable or low-carbon fuels diminish the grid's carbon emissions. Since EVs get their energy from these grids, this is how you would determine an EV's carbon footprint, relative to which grid it is being plugged into.

You are just lying about what I write. No emotions here and I did not say zero emissions. Stop lying.

Some of you guys are just too used to arguing against people that are against diesel. These last few posts I've made have all contained elements of me telling you what I did not say, despite the fact that this is all text and the text is still there mate

Did I or did I not immediately mention the fact that an EV can draw its power from a coal plant, roon? Does that not imply that it uses the power grid for that? Why, then, do you think you need to explain this to me? It's right there in my post for god's sake mate

Look at the numbers again though; specifically the notes at the bottom of the chart. What does it say there? Do you think it's an honest comparison to make, to bring i countries such as India - a country that is BUILDING it's flippin power grid as we speak into this? Is that an honest way to argue do you think?

So would you like to go back to reading what it is that I _actually_ write and comment on that instead of making me have to explain to you what it is that _my text_ actually does not say?

Downvote me all you want. Do what you have to do mate

[Greg Locock]

I've seen many crazy figures for the CO2 payback time for panels and batteries.

If the whiners will let me post it, here's a summary

The energy requirements for the production of PV modules and BOS components are analyzed in order to evaluate the energy pay-back time and the CO2 emissions of grid-connected PV systems. Both c-Si and thin film module technologies are investigated. Assuming an irradiation of 1700 kWh/m2/yr the energy pay-back time was found to be 2·5–3 years for present-day roof-top installations and 3–4 years for multi-megawatt, ground-mounted systems. The specific CO2 emission of the rooftop systems was calculated as 50–60 g/kWh now and possibly 20–30 g/kWh in the future. This leads to the conclusion that in the longer term grid-connected PV systems can contribute significantly to the mitigation of CO2 emissions.

Those are old figures but 20–30 g/kWh is much more than I'd expected, although obviously a lot less than coal (at least 1000 g /kWh). figure on 200 Wh/mile from a good EV.

The batteries are much harder to figure out, after all much of the energy content is in refining raw materials which can be usefully recycled.

here's an article claiming 17.5 tons

http://www.popularmechanics.com/cars/hy ... fake-news/

I didnt try and follow his maths mine is better.

So it takes a much to make a battery as a car!

So the equation for a solar powered EV is 100 to build the car, 100 to build the battery, and 30 for the panels... so 230 g/km, same as the Mondeo

That is so funny. OK I cheated, obviously an EV without a battery is less complex than a Mondeo, and not every EV has a 100 kWh battery. Even so, looks like the cynics have a reasonable point of view. if you care about CO2 which i don't.

[hurril]

It's also disingenuous to bring CO2 into the production stages for someone that never cares about those numbers anyway. You make CO2 accounting matter when it suits you to do so. Nice.

[Greg Locock]

Here's the source for the PV stuff

http://onlinelibrary.wiley.com/doi/10.1 ... C/abstract

So now you've got sources and numbers.

[hurril]

Here's the source for the PV stuff

http://onlinelibrary.wiley.com/doi/10.1 ... C/abstract

So now you've got sources and numbers.

You are still missing the point and also arguing against a position which I do not hold.

[hurril]

Producing and using iPhones also emits plenty of CO2 but you would not use that as an argument _for_ getting a diesel generator to drive the production and/ or charge its batteries.

That is the point you seem to be making with regards to preferring diesel trucks over EV:s because the latter emit more CO2 with some of that creative accounting.

If you really want to push this idea, you ought to be for not building new cars at all because the really old ones are already here.

[Shrieker]

I didnt try and follow his maths mine is better.

So it takes a much to make a battery as a car!

So the equation for a solar powered EV is 100 to build the car, 100 to build the battery, and 30 for the panels... so 230 g/km, same as the Mondeo

That is so funny. OK I cheated, obviously an EV without a battery is less complex than a Mondeo, and not every EV has a 100 kWh battery. Even so, looks like the cynics have a reasonable point of view. if you care about CO2 which i don't.

I'm guessing we can expect improvements in the coming years ? What's math saying about tesla's semi ?

[Phil]

So... to summarize and on the topic of EVs:

- creating batteries carries a carbon footprint
- using electricity carries a carbon footprint (efficiency of the power source relevant)

vs.

- PVs naturally carry a carbon footprint by combustion (efficiency of the ICE)
- drilling, refining, transportation and distribution of oils carries a carbon footprint
- lots of testosterone being pumped out the exhaust in form of sound-waves

But there is one more point, that being that there may be an argument to be made that it's easier to tax and control (influence) the efficiency of creating power sources for electricity rather than doing it on millions of PVs roaming around polluting the air in highly populated areas. Also that it's easier to achieve a higher thermal efficiency in a power plant than it is in a car that is more dependent on usage/driving etc? Also that the carbon footprint of electricity might come down in the future with more governments looking to invest into clean (but expensive) energy (solar, wind, water)?

Did I miss anything?

[Just_a_fan]

There is no doubt that EVs pollute just as ICE-equipped vehicles do. You can't make a car, irrespective of the motive power type, without pollution.

Where EVs are much better is in urban local air quality. Local air quality is now the biggest issue with cars - CO2 is being driven down but NOx, particulates etc. are not, at least not at the same rate. EVs don't produce NOx locally and they produce much lower quantities of particulates (from tyres and brakes). Politicians are using taxation as a means of trying to move urban populations away from ICE and towards EV. There is a major society benefit here in reducing illnesses associated with poor air quality. This makes a lot of sense provided the generating and distribution capacity is available.

The biggest issue for society is how to generate and distribute sufficient electricity to charge the large numbers of EVs that politicians want to see on the roads. Ideally generation would be by "green" methods e.g. wind, wave, solar and nuclear. Distribution is just a matter of having sufficient numbers of wires of sufficient capacity. Grid storage would be beneficial in some cases.

[Andres125sx]

True, no catalyst, they only need 100kg of fuel to cover 300km

Wait. Stop right there. Do you think a Tesla of any model can turn even a single lap of the Nurbergring even with those giant battery packs? Nope. Thus for high performance, the F1 car gets better mileage.

Who said a word about high perfomance? We´re talking about efficiency and TC brought F1 efficiency as a model for Tesla

[Andres125sx]

how much higher are the social costs ?
(if the electricity is untaxed but the diesel is taxed)

Social costs higher? No way.

Diesels are taxed basically because they´re throwing poison to the atmosphere, CO2 is far from the only problem with ICEs. Taxes are only trying to compensate the health problems they cause

That’s not entirely true by the way. Where do you think a large amount of the money comes from to build and maintain shiny roads and infrastructure?

Just to add - in my country, the tax goes 50% towards road and infrastructure, the other 50% directly to the state. The tax accounted for roughly 8.5% of the entire state income in 2012. Zero goes to health.

I guess different countries have different laws. Anycase I was just trying to point to the fact people focus too much on CO2, when ICEs emit a lot of harmful substances wich causes a lot of respiratory problems on people who live in cities.

Simplifying the EV vs ICE debate to CO2 is simply absurd



Basically I think this debate is absurd because of two reasons:

1- ICE pollute more than EV if you don´t live in India... even nowadays
2- EV footprint is directly dependant on grid emisions, and grid emissions are reduced year after year as most countries in the world are constantly increasing their renewable energy grid, so comparing total emissions with today data is flawed. An ICE you purchase today will pollute the same today, a bit more next year, and a lot more in 10 years (ICEs efficiency decreases with wear, reduced smoothness due to use, etc.), while an EV purchased today next year will pollute a bit less, and in 10 years it will pollute less due to increased renewable energies on the grid


And that´s only talking about CO2, ignoring ICEs also emit SO2 for example so, if the real debate is what´s better for our health and the planet.... what debate?

[Phil]

You quite evidently completely missed TCs point which was about thermal efficiency.

[Greg Locock]

I haven't got the specs for the Tesla semi, but given the claimed life of a million miles then it is a lot better than the car, ton for ton.

I realise the semi got some attention, but wouldn't a bus be a better fit for an EV? Low speeds, lots of stop-go, probably weight insensitive?

[flmkane]

True, no catalyst, they only need 100kg of fuel to cover 300km

Wait. Stop right there. Do you think a Tesla of any model can turn even a single lap of the Nurbergring even with those giant battery packs? Nope. Thus for high performance, the F1 car gets better mileage.

Who said a word about high perfomance? We´re talking about efficiency and TC brought F1 efficiency as a model for Tesla

It's unfair to cherry pick and misquote one paragraph from a three or four paragraph post.

[roon]

Fun infographics at 1:18.



"The Tesla Semi will go zero-to-60 in five seconds. That's by itself, or with a trailer." Even at 80k lbs trailer weight, max legal highway limit, it's only five seconds slower to sixty than an unladen diesel truck. 20s and 15s, respectively.