141–150 of 278 posts
Imagine the government draining your tank at the gas station instead of filling it.
Imagine the gas station selling you a tank of gas for $10 and buying it back for $15 later in the day, all while your car sits on your driveway
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This makes much more sense with large lifepo4 chemistry batteries that are expected to outlive the car by a wide margin. Lifepo4 batteries > 50kwh should easily handle 500,000 miles. Higher performance lithium ion will degrade at a rate faster than any expected return from a scheme like this. At least in Northern California it’s now cheaper for me to run solar+battery off grid than to pay pge. Lifepo4 pushes it over…
> If off-grid is competitive, selling at peak prices is a no brainer. So why isn't the utility managing the storage directly then? Aren't they best suited to do this??? Or is this article just saying that EV car batteries could ?
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Did you know that the standard DC chargers communicate with the vehicle using PLC (Powerline communication) chips even though that communication is not over the high power conductors? I've always had the feeling the grid operators got that included because they thought they were going to communicate directly with the battery management system to control it as they wish. It never happened and now the standard is stupi…
Assuming V2G means Vehicle to Ground, this is something I would like to see for the following use-case. I would like to use my car battery as a temporary home battery in the inevitable case of a grid outage. This opens the option to bring energy home from another location. Reduce or eliminates the need for a battery in a grid-tied house. Am I crazy? Edit: Granted that doesn't mean the energy company can use my car's…
The former is pretty straightforward. The latter would need a lot of electrical upgrades to the house. (I'd expect you'd need to do about the same thing that people do when they get solar, which is to replace the meter with something that can measure power flows in both directions, and is smart enough to disconnect the solar panels from upstream power when the power goes out, so you don't electrocute people trying to fix the power lines. If you don't have a local battery, that means basically turning the solar system off in a power failure.)
If you aren't planning on selling storage capacity to your local utility, maybe all you really need is an automatic shutoff switch to disconnect your house from the grid when the power goes out.
Either way you'd need some sort of power inverter to convert DC to AC. That could be built into the car, or it could be attached to the house.
I think EV owners would need to find some level of compensation for the additional cycles they would incur. Electric vehicles are expensive because of the battery so deteriorating the life of one of the most costly parts of the car doesn't feel like a great solution.
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I opted NOT to sell my excess to PNM (New Mexico), because the agreement allowed them to claim my 6.7kW array as part of their own progress towards renewable conversion. What I didn't understand was that I ended up with an even better deal! I get back the excess kW/h on a 1:1 basis. This is much better "pricing" than I would have received if I had sold it for cash. Granted this model only works if there's a part of t…
What's wrong with them counting your solar as part of their conversion? Nothing wrong with you declining if the price isn't high enough, but if they're paying someone for solar power, whether it's an individual or a company, I think they should count that as part of their renewable portfolio.
I think EV owners would need to find some level of compensation for the additional cycles they would incur. Electric vehicles are expensive because of the battery so deteriorating the life of one of the most costly parts of the car doesn't feel like a great solution.
Indeed as this becomes more of an option I trust that car producers could look at engineering their batteries with this in mind.
It feels like an iceberg has been slowly turning over for the past 10 years, and is now flipping quickly. Economic growth is now more correlated with carbon reduction than increase. The useful work of preventing coal plants is over and we need to switch gears to get home appliances, ev cars, solar, wind and transmission out as quickly as possible. Environmental groups and common knowledge haven't caught up yet, but t…
I think environmental groups are just the tip of the iceberg that gets blamed for things because they're visible. They just don't have that much political clout (aside from the very large "environmental group" that's people who are concerned about climate change -- which may be a majority of all living humans at this point).
As an example, consider strict environmental regulations on oil refineries. It seems like those must be pushed by environmental groups, right? But it can also be a case of regulatory capture by the incumbent refineries. The regulations don't apply to them because they were grandfathered in, but the regulations are their moat protecting them from any upstart competitors.
Or consider fuel economy standards. Those must be pushed by environmentalists, right? But then why do light pickup trucks have very strict fuel economy standards, and larger trucks have looser, easier-to-meet standards to the point where it's hard to actually make a light truck that conforms to the standards and isn't really slow and underpowered. It's almost like the incumbent automakers have been successful at lobbying for regulations that protect the lucrative market for oversized trucks by ensuring that smaller trucks are unappealing, unavailable, or too expensive. (The chicken tax is another example.)
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I have 100k miles on my 2018 Model S having Supercharged it the majority of the time the last four years. It has only 6% battery degradation of the 100kw pack. Tesla warranties their powerwalls for 15 years when configured as part of their aggregated virtual power plants. The batteries are demonstrated to be durable. New LFP chemistries that are heavier but more stable are ideal for stationary storage and high cycle…
> if you don’t want or can’t get dedicated stationary storage (although it comes with generous federal, state, and utility subsidies in California). I installed stationary LFP batteries (from Enphase) on my house in CA 1.5 years ago, but I then discovered that the state and utility subsidies [1] only apply if you are in a very low income (for CA) bracket, have a health condition that requires backup power, or live in…
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The 2 cent figure is per kWh, not per cycle. Multiplying by the 75kWh pack size gives $1.50. What about the remaining 10X? The calculation you’re doing isn’t the right one, because the battery wear isn’t directly related to miles driven; Tesla’s battery warranty is pricing in a “full stack” picture of battery degradation while actually driving. Your computation implies that the battery has 0 value after ~1000 cycles,…
The nature paper seems to assume the car is doing a fast discharge to supply enough energy to the grid, so something like supercharging-- probably not the best on the battery. Tesla only warranties 375 cycles, so not sure what you mean? The 18 cents/kWh already assumes a more generous 1,000 cycles. The $12,000 battery pack replacement cost is current market price, including any recycling or potential reuse of old pac…
Edit: from the paper:
> We assume the home charging power as 1.92, 6.6, 22, and 1.92 kW for small, mid-size, large BEV, and PHEV, respectively
I don’t think the 22kW assumption is reasonable, but the others are comfortably within current L2 AC charging rates.
Considering that most "EV batteries" are actually just smaller batteries glued together to bigger cells, modules and packs, I don't think this is as much of a win as people think it is. It's like saying "We can green the planet with Duracells." Ignoring what's in the batteries or what it takes to manufacture them. Or how they degrade over time. We may need to look at hybrid battery solutions with alternative energy s…
Cylindrical cells are fine as long as they can be made cheaply and the costs (economic and environmental) can be amortized over a long life.
We'll probably start seeing more LFP batteries in coming years, which are more ideal for grid storage. (They're cheap and have a long life.)
Battery recycling needs to improve, but we'll probably get there eventually. Right now the volume of batteries that need to be recycled is just not very big. The Nissan Leaf, for instance, was only just released in 2010. Most of the EVs that have ever been manufactured are only a few years old.