Dirty Mathematics

Dirty mathematics makes a mockery out of clean energy on which electric vehicles (EVs) depend.

China puts together a typical Tesla lithium-ion battery on the coal-fired power grid. That alone releases 13,500 kilograms of CO2 emissions equivalent to the carbon pollution released by a conventional gasoline-powered car traveling 33,000 miles. This is a carbon-intensive manufacturing process, whichever way you slice it.

Also, most EVs are out and about during the day, right? That means solar-generated electricity won't be available for recharging them when nightfall comes. If and only if you happen to live in a solar panel-covered desert, then you may be able to reserve enough recharging power after sunset. Now, don't tell me that you have already set up a wind turbine in your backyard.

More than likely, an EV dealer's sale pitch is meant to cover up the devil that is always in the details. Clean-and-green buyers beware.


Author: renqiulan

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To research this subject, one might want to start with the following MIT report:https://meche.mit.edu/news-media/how-much-co2-emitted-manufacturing-batteries

-- 关于EV夜间充电的问题，我可以给你部分的回答 -- 工业用电主要在白天。传统上，为了满足白天高峰用电，电厂的capacity必须满足其需要。可是夜间用电少，电厂有很多idle。现在很多的人家既有solar panel，又用EV （我也如此），于是白天家里发的电进入grid，夜间从grid免费充电。电厂白天的供电从千家万户的solar panel那里得到帮助（电厂因此burn much less coal)，夜间电厂的idle减少，它们发电给EV充电。我本来以为电厂不喜欢居民家里install solar panel，后来得知因为上面的原因，他们其实欢迎太阳能。

-- 就我个人来讲，我自己的solar panel在过去一年里产了14000千瓦时的电力，它的超过我室内的用电需要，于是用多余的电给EV充电，大大减少了gas (for cars) 和 natural gas (for heating）的消耗。至少在这个局部，math 是很清楚的，也是应该提倡的。它跟China, Tesla, California 等都无关。14000是来自太阳的能源，它减少了化石能源的使用，进而减少了CO2的排放。

clean nor green at its source. That's just a secondary issue, though. The No. 1 issue is the very very dirty battery-manufacturing process. Also, mining lithium is by no means clean or green. EV drivers are end users. They may not care how their EVs come by or where they come from. But if we are truly serious about clean and green technology, then we need to take a closer look at how and where our EVs were produced. If you can, use my MIT link and take a deeper dive in the EV issue. Goodnight!

It's true that at the current renewable energy penetration of the grid, making an EV generates much more carbon emissions than making an ICE car. However, the carbon emissions from operating an EV are much smaller than those from operating its ICE counterpart even at the current grid emission intensity. Overall, taking the cradle-to-grave lifecycle, an EV will generate 28-64% lower emissions than an ICE car in the US. This is from a study by Ford Motor in 2022 :)

straightforward --  在目前情况下，如果EV的电来自coal-fired power plant，那么使用EV的意义是大打折扣或者值得怀疑的。然而，如果EV的电力来自家中的solar panel （我的情况），那用EV的优点远远超过它的问题。（用目前的技术）生产电池尽管dirty，break down到一辆车、一个电池，它造成的污染依然是有限的、较少。而这一辆车如果用solar panel的电，它就如同一个10-15年的perpetum mobile （saving ~15000 liters of gas in its lifetime) .  这种情况下no brainer.

了解math model的人都知道，如果它的variable太多且不确定，结论就不靠谱，结果就是公说公有理婆说婆有理。我避免这种无谓的争论。

我不是一个green energy的热心推崇者。我认为RATIONALITY非常重要。关于solar energy 和EV，我力求减少我自己的“math model”中的变量数，然后得出相对可靠的结论，并采取行动。