5 ms·
For grid bases storage, energy density does not really matter. What matters is cost and longevity. There are a few emerging battery chemistries that promise to
by jillesvangurp 3y ago
For grid bases storage, energy density does not really matter. What matters is cost and longevity. There are a few emerging battery chemistries that promise to be cheaper and more durable than lithium ion and less vulnerable to hot/cold temperatures as well. The energy density for these is not good enough for things like cars or trucks. But that doesn't matter if the primary application is setting up stationary storage in some field in the middle of nowhere. You literally can just plonk down some containers and wire them up. What matters is being able to deploy these things quickly and cheaply and not having to expend a lot of energy on heating/cooling or worrying about these things catching fire.
For cars and trucks, current batteries are actually fine. Higher energy densities are mainly nice for things like high end sports cars where the form factor prevents cramming in more battery. But less so in freight trucks. Saving a few hundred kilos of mass on a truck that pulls 80 tonne is just not that valuable. It's nice but only if it doesn't raise the price too much. So what if you need a two tonne battery? The main constraint here is cost, not weight.
The aviation market on the other hand has an insatiable demand for high energy density storage. Hence companies like CATL announcing 500wh/kg batteries recently. That's double what you'd find in a high end car these days. And apparently they are working on even higher energy density batteries already.
Probably these are really expensive and hard to get. But it's going to add quite a bit of range to things like VTOL planes, drones, and other flying things that run on batteries. So, a NASA battery with high energy density and a few other nice properties (like needing no cooling/heating) could be worth the extra cost in this market. And better longevity means more time in between expensive overhauls as well.
- VBprogrammer 3y ago> Saving a few hundred kilos of mass on a truck that pulls 80 tonne is just not that valuable. From my understanding of the trucking industry, in many sectors, this isn't true at all. For example, in tipper trucks where you are carrying literal dirt and rocks from one place to another every kg counts and tare weight of the truck is very much a consideration, even in the relatively minor variations between diesel trucks. In the US weight restrictions are even lower than in Europe in many states.
- atoav 3y ago> In the US weight restrictions are even lower than in Europe in many states. Given that road wear grows to the fourth power (!) with vehicle weight, I hope you guys feel well with the fact that your tax dollar subsidizes those ultra heavy trucks.
- VBprogrammer 3y agoSeems reasonable given, you know, they are also delivering our food, fuel and basically anything else you need or want. They also pay a considerable amount of road tax and taxes on fuel which would make most people in the US plot a coup.
- onlyrealcuzzo 3y agoAh, yes, because trains clearly could not do this and never did in the past. There is no alternative.
- VBprogrammer 3y agoTrains have never delivered to individual retail stores, half finished housing estates or petrol stations. Perhaps reserve your sarcasm for when you aren't saying something stupid.
- onlyrealcuzzo 3y agoYes, because none of those things existed before the automobile.
- VBprogrammer 3y agoI'm not even sure what you are trying to say. Perhaps try having a grown up discussion rather than trying to win internet points via your superior sarcastic smack downs. Retail stores certainly existed before the automobile. People walked, biked or used horses to get to them. Horse and cart were used to deliver things to them.
- jojobas 3y agoCurrent electric semis are only good for hauling potato chips (i.e. mostly air) for any distance over 100km. Weight is very very valuable on both passenger cars and commercial trucks. Hauling those extra 300-500kg vs a comparable size sedan comes at a steep cost too, as increasing weight requires stronger/wheels body, wheels, brakes, even engines. There is a huge demand for higher energy density, preferably of a non-explosive kind.
- gameoverhumans 3y agoAs I understand it, electric cars are actually surprisingly polluting, which is a consequence of their battery weight and particulates from tires: https://dynomight.net/tires/ https://dynomight.net/tires/
- jakobnissen 3y agoThe blog in your link seems to conclude that electric cars pollute less than petrol cars overall. Still, if the blog is true, it's still surprising that such a large amount of air pollution comes from tyres and brakes. A little Googling does support this claim.
- jojobas 3y agoIt could have something to do with the fact that in order to regen-brake a 1800kg car at your typical 0.5g at 100 km/h you need some 270kW of motor/generator power. This is the main reason your Teslas and Polestars have these otherwise outlandish engines, and if you already have it, why not accelerate at traction limit, creating all these aerosols and what not.
- goodcanadian 3y agoIt is extremely atypical to be braking at 0.5g. That is an emergency braking situation, in which case, it is perfectly reasonable to be engaging the mechanical braking.
- dabeeeenster 3y agoEVs do 100% need to get lighter. They are still quite a bit heavier than their ICE equivalents and tyre wear is (IMO) underappreciated as a toxin/pollutant.
- jillesvangurp 3y agoThere are quite a few lighter EVs. Including some classic car conversions that actually manage to be faster and lighter than their originals. Those cute little EVs that are mass produced in China are far lighter than the super sized trucks people in the US drive. And of course any muscle car burns out its tires, brakes, and has terrible fuel economy.
- ilyt 3y agoMost people buy neither small EVs (they have family) nor musclecars (they, again, have family)
- littlestymaar 3y agoYou definitely don't need a 3t truck to carry your family, especially when you know how small modern families are… The average household size in the US is 2.53. And 63% of households are only made of one or two person (that is, the majority actually doesn't “have a family”), which fits in 482 kg Citroën Ami. Also the most common car in Europe (Dacia Sandero), which is a 5-seater only weights 1 036kg. Gigantic American cars are a cultural phenomenon (which is mostly ad-driven by the way), it doesn't relate to an actual need.
- bumby 3y agoI’m not discounting the cultural part because it’s a big factor, but you’re also missing that the US has more stringent safety standards that significantly drive up weight. There’s more reasons that those little Opals and Citroëns aren’t sold in the US beyond cultural norms.
- 3y ago
- panick21_ 3y ago> Higher energy densities are mainly nice for things like high end sports cars where the form factor prevents cramming in more battery. But less so in freight trucks. Saving a few hundred kilos of mass on a truck that pulls 80 tonne is just not that valuable. Disagree. Car and truck makers try to optimize for grams and saving a kg of production vehicle is considered a huge engineering victory. Saving 100s of kg is a gigantic deal.
- bumby 3y agoThis is true. Just look at Fords decision to go with an aluminum bed on their F150. Going with a material that is more expensive and less durable on their best selling vehicle that’s also a work truck is a big deal, but worth it given the weight savings.