tomo,
DPFs seem to be a frequent trigger for scrapping vehicles of a certain age. I think I mentioned a Peugeot DPF problem here a while back. When I looked into it, the firmware would issue a non-critical warning that the DPF needed attention. The car continued to be driveable, but the ECU would no longer schedule any regens/burns/whatever. If you didn't get onto it within a few thousand miles, the car became undriveable, and the DPF was not economically reparable. With more expensive cars like Jags and Landies, it might be that the economic alternative to scrapping is legal action.

Dubai should probably let Venice keep its stranglehold on gondolas.

Solar to the grid video was very well done. I hadn't thought of all the inverters *adding* strength to frequency deviations, but that looks very plausible. Just the opposite effect of a nice big flywheel.

I was intrigued with one of the comments. It's by a linesman. Here's the meat of it:

... when we open the switch to de-energize the transformer supplying a neighborhood (in our case an average of 150 households/transformer) with a lot of solar, on rare occasions it will remain energized, backfed from the households solar production. This happens because in the right conditions the solar panels will produce the same amount of power as the households consume, so there's no current flow through the transformer.

MikeHig,
I've heard the charging of lithium ion batteries likened to filling a balloon. I don't think it's a wonderful metaphor, but you can picture the balloon getting saggy after it has been stretched a few times. I think it also conveys the fuzziness of an "absolute limit" when it comes to charging. You only learn a balloon's limit by the bang that comes from going beyond it, and it will change depending on previous inflations.

It's a bit of a new thing for car drivers — each time you fill your tank it gets smaller — but it's something one could adapt to.

I think James May put his finger on it in that video posted here recently: range is not the problem, what drivers suffer from is recharging anxiety. If recharging were as convenient as refuelling, even an 80 mile range would be tolerable. That's a chicken and egg problem which the manufacturers cannot solve. The best they can do is offer ever-bigger batteries. A very mixed blessing.

Robert/tomo: it seems that all EV batteries have some "headroom" in that the available capacity is always some kWh lower than the absolute total capacity. So road tests will quote stuff like "it has an 85 kWh battery of which 77 kWh is useable". That margin was what Tesla temporarily released, as mentioned by tomo.
My understanding is that this allows the car to maintain its range even with a bit of battery degradation. Also the cells do not have to be charged to the absolute limit to reach the nominal 100% capacity.
Interrogating the battery will show the true available capacity as well as all the other stuff.

tomo,
We were starting to hear some guff about coral bleaching at the end of last week. I think the plan was for a blitz like you are seeing there, but the stabbing at the weekend stole their thunder. I expect they'll regroup and give it another push in a week or two.

The GBR has been "under threat" all the time I've been in Australia, and always sensationalised in the news. Not much fun owning a "crown jewel" if all you do is agonise over the fear of losing it. Half a century passes and we're still agonising. You'd like to hope that the boy who cried wolf effect would kick in, but it seems the collective memory works like Clive Wearing's.

On Tesla being able to tap extra potential in the batteriy in an emergency, I conjecture that Teslas maintain charge state as net charge stored, which involves keeping a tally — like a two-way odometer — of charge in - charge out. The software would have low- and high-water marks for this meter: stop moving when you reach the low; stop charging when you reach the high. Presumably they researched the values for the marks by balancing range against safety and cell longevity. For the emergency they struck a different balance and set a lower low-water mark. One little number buried somewhere in the firmware.

That's probably all fairly obvious to everyone. An interesting question is how they adjust the high-water mark as the cells degrade. Might be empirical, or by mathematical model. Problems with both IMO.

Empirically, you'd have to overcharge occasionally to see when voltage starts to lift rapidly, then set the high mark to some lower value. Obviously there's a cost to longevity in running it up against its limits.

Mathematically, you'd have to trust the quality control of the cell packs, and of the model. Things might get ugly if later cell packs aren't at least as good as the originals.

But the high-water mark would give an excellent indication of battery degradation for that 8-year warranty. It should also be very highly correlated with the car's range.