Without thinking too hard about the efficiency, it's clearly just not a _safe_ proposition with our current best (most energy-dense per weight) batteries.

There are regular train/truck transports with much more dangerous and volatile chemicals than lithium.

The current dangerous transports are not nearly as widely deployed as battery trucks would be required to be to be viable.

Gasoline has much more energy density per weight than batteries, and we truck that around all the time.

Gasoline isn't self-oxidizing, so you can put out a gasoline fire (instead of just "letting it burn"). Also gasoline doesn't burn at 2000C, I believe.

Right. That’s one reasons why transporting electricity by truck is a terrible idea.

Batteries are heavy. The heavier you are, the more power you need to move. This is why almost all battery based truck designs are very short range.

Why not then just charge batteries where you need them and keep them at place for when the Sun goes to sleep? Why would you transport batteries around?

Because some places have excess amounts of hydropower and other places have huge energy shortfalls. Not everyone is using solar/wind power. It is a pretty straightforward arbitrage. I have no idea if it's worth doing, though.

Some Battery train companies include this in their plans.

Even non Battery electric trains can speed up or slow down at different points (while still staying on schedule) to act as a variable demand for the local grids. Batteries just extend that.

https://arstechnica.netblogpro.com/science/2021/11/can-we-ru...

> The analysis becomes very interesting when the researchers leave freight behind and start thinking about what could be done with many big, mobile batteries. Even without moving them, freight companies could use their capacity to provide grid stabilization services or sell back power when the price gets high. In extreme cases, this system could actually pay for the entire infrastructure.

> "Preliminary estimates of the most expensive 90 hours per year in the ERCOT [Texas] market, for example, show that batteries could be discharged at $200/kWh, potentially generating enough revenue to pay for the upfront battery cost in a single year," the study says.

> The batteries could also be moved to locations that have been struck by power outages or natural disasters, towed there by locomotives running on diesel instead of draining the batteries.

> Even non Battery electric trains can speed up or slow down at different points

I want this for everything with a battery, it’s own internal thermal mass or things I don’t need to complete as quickly as possible.

E.g.: laptop, washing machine (clothes or dishes), dryer, refrigerator, hot water heater, hvac, etc.

It just seems so underdeveloped on the consumer side.

Hot water heaters are the the low hanging fruit here. Australian water heaters have been using overnight coal power for decades with very basic systems.

https://es.catapult.org.uk/project/consumer-insight-unlockin...

It’s pretty obvious that it isn’t at least not with lithium batteries. They are way to expensive and heavy. e.g. assuming an around 36 000 kg total payload the truck would have to use up 1/3 of all the electricity it stores just to travel around 600km. This combined with general inefficiency of batteries and the extreme cost would make it an absolutely terrible alternative to HVDC.

I think a truckfull of batteries would have barely enough energy to transport itself

No, they're not.