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blackoil

In how much time does a solar/wind project becomes carbon negative compared to coal?

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It never becomes carbon negative? It just emits less overall.

To become carbon negative it would have to suck carbon back from the air.

I think they meant how many years until break even vs conventional alternatives

Again, what is "break even"?

For example, in electric vehicles, the initial production emits much more than a conventional gas car (mostly due to the battery). A lot of people don't realize that as much as 30% of a vehicle's lifetime emissions can be in the initial production alone. As a result it takes ~28-68.2k miles (in the US) for an EV to emit comparatively fewer emissions

Are you looking for a number like that? If you are then you would have to more narrowly defined your use-case. There are far too many factors, infrastructures, conditions, technologies, etc to consider

Those numbers seem much too high, for example the projection for a Model 3 is that you'd only need to drive it 13K mi / 22K km[1]

1: https://www.reuters.com/business/autos-transportation/lifeti...

My numbers come from a study published in Nature in 2022:

https://www.nature.com/articles/s41893-022-00862-3

The Argonne model relied on in the article you linked is quite dated at this point and has its limitations (which are acknowledged by the authors of it themselves).

I see, so that 28K number looks solid, the 68K upper bound applies to a scenario where someone doesn't switch to an EV but buys one and still keeps driving an ICE vehicle too, which seems odd - I would think many drivers could use an EV for all their shorter trips (certainly shopping, likely commuting), but paying to register/license an extra car just for the occasional long trip doesn't seem very practical.

That's a fair take. As stated in the study that scenario is based around actual documented EV usage behavior amongst owners

PS, cheers for actually reading the paper

> As a result it takes ~28-68.2k miles (in the US) for an EV to emit comparatively fewer emissions

That's really not much to be honest and the US doesn't exactly have the best grid in the world in terms of carbon either.

Yeah I don't think it's that much either. I feel a lot of readers are reading my comments as if I'm being hostile towards renewables and downvoting me because of that assumption.

I am not opposed to renewables, nor am I trying to argue that "it takes [insert amount of miles that's well within the average lifespan of a car] for EVs to break even" somehow implies "EVs bad"

Obviously I don't support the continued usage of oil and coal as energy resources

Negative compared to a preexisting coal plant? It's probably a matter of weeks.

Note that it takes 2 orders of magnitude more wind turbines to replace that preexisting coal plant. (i.e. >100 turbines for 1 coal plant)

Yes, that's factored in. The average coal plant outputs 830 MW, and obviously nobody is building wind turbines that large. That's why wind power installations are called "wind farms".

The figure I recently read was that solar panels are recouping their manufacturing carbon impact in less than a year when compared to conventional fossil mix.

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