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childintime 6 hours ago

Wait? No electric tractors yet? Swappable batteries would be perfect.

folmar 2 hours ago | parent | next [-]

Electric excavators are there, as they are low duty cycle, see sibling comments for details, but high load percent for long time is a killer for battery tech.

I could imagine tethered tractors with power line tensioned in the air, but the grid building cost will be quite high for intermittent usage. Only some land usages and plot shapes would work economically.

cmrdporcupine 17 minutes ago | parent | prev | next [-]

There's been a few. The big manufacturers don't really want to make them, and for the last decade just show off expensive concepts at industry shows and that's it. The small companies only get investment by making a VC play for "autonomous" and "smart" agriculture; they soak up investment, make very expensive product, then go out of business.

I think Monarch tractor just folded up and sold their assets, for example. They were a nice looking product but did what I described above.

Innovation here will happen in Europe and China, not here in North America. "Tractor" here in North America means big giant machine that is owned in a fleet by a giant corporation that manages multiple properties, and works over a dozen fields in a few days.

Every time I've looked into it for my hobby farm, a compact utility tractor that is electric ends up either being vapourware or twice to three times the price and missing features.

bluGill 4 hours ago | parent | prev | next [-]

the battery in a tesla would run a medium tractor for less than an hour. The tesla can produce more power - but soon it is up to speed and so making a lot less. Tractors are expected to produce their full rated power for 10 hours without stopping.

cmrdporcupine 15 minutes ago | parent [-]

Maybe a row crop tractor, but a utility tractor is not running continuously for 10 hours. Just running around doing chores and a lot of that time is sitting idling a diesel engine.

quickthrowman 5 hours ago | parent | prev [-]

A tractor does actual work like pulling an implement like a plow or spinning the PTO to power a machine like a wood splitter or well drill.

Airplane engines are rebuilt every 5,000ish miles because they’re constantly running at like 50% load, it’s much harder on the engine than moving a car, a tractor is very similar.

Car engines do very little work once you’re up to speed, it only takes a fraction of the max power available to keep the car moving. This is why EVs are possible.

Running a tractor engine under load requires a lot of energy, battery density isn’t quite there yet, diesel has around 50x more energy by weight than a battery.

ericpauley 4 hours ago | parent [-]

Off by an order of magnitude. Average TBO (which airplane engines routinely exceed if they don’t rust out) is 2,000 hours assuming piston, or about 300,000 miles for a Piper Arrow at cruise speed.

jaza an hour ago | parent | next [-]

Thanks for clarifying, I thought that sounded wrong - otherwise aeroplane engines would have to be "rebuilt", each and every time, after more than half of all international flights in and out of Australia (5000 miles, aka 8000km, is just down the road to grab a sausage roll for us!).

quickthrowman 3 hours ago | parent | prev [-]

My apologies, I forgot that airplane engines are tracked by running time and not miles!