Electric cars

AnotherJoe

iolanthe07 wrote: »

even straw chewing rurals currently wondering what this new fangled lekttric is

Don't be so bloody patronising. These 'straw chewing rurals' are using technology in their farm equipment you can only dream of.

Don't be so precious. That was aimed at the rurals who think they get an indefinite free run to poison us just because it's cheaper for them to run a polluting diesel even if townies must send theirs to the crusher.

Gloomendoom

AnotherJoe wrote: »

No patronising meant, that was a poor attempt at humour but even super sophisticated rurals running the latest in electronic tech on their farms don't get an indefinite free run to poison us just because it's cheaper for them to run a polluting diesel.

Us straw chewing rurals are in the middle of harvest and I have wondered how large machines like combines could be weaned off diesel. They are typically used for short periods during the year and then laid up in barns for months on end. If the weather is right, when they are working, it can be 24 hours a day for one, two or three weeks at a time. Virtually non-stop.

AdrianC

Quite. Anybody who thinks electric combines or tractors are viable doesn't know the first thing about agriculture.

Herzlos

AdrianC wrote: »

Quite. Anybody who thinks electric combines or tractors are viable doesn't know the first thing about agriculture.

I don't know, there's no reason they couldn't be viable. Lots of torque on what's already a heavy machine, generally covering minimal range at relatively low speeds.

They sound ideal for electrification. Tractors would be a lot easier than combines though, just because of the sheer power difference.

AdrianC

No, you don't understand the problem... They are working 24x7 when they're working. They are substantial bits of kit... They're fitted with what are basically truck engines - 8-9 litre diesels are typical in the midrange models - and they are working full-whack when they're working.

Those midrange models are 12-13 ton machines, empty, with grain tanks that can be 9-10 cubic metres in capacity. They aren't the size they are for fun - they're full... Where, in that, are you going to put suitably substantial amounts of battery - and how are you going to be charging them? Or will you be running an extension lead across the field?

Gloomendoom

Herzlos wrote: »

I don't know, there's no reason they couldn't be viable. Lots of torque on what's already a heavy machine, generally covering minimal range at relatively low speeds.

Really?

How big will the battery need to be to run a four to five hundred kilowatt combine 24 hours a day for a week? Do the sums.

There is no down time. They would have to be recharged on the fly.

AdrianC

I'm waiting for "But you could take them back to the farmyard and swap batteries there" - forgetting that the yard might be an hour or more's drive away in a combine...

Car_54

Herzlos wrote: »

I don't know, there's no reason they couldn't be viable. Lots of torque on what's already a heavy machine, generally covering minimal range at relatively low speeds.

Apart from the problems that others have already pointed out, the low speed is irrelevant. A combine is effectively a mobile factory - cutting, threshing, sieving, chopping, etc. That is where most of the energy is used, not in simply moving the machine around.

Similarly, a tractor needs the capacity to power other machinery in addition to moving itself from A to B.

almillar

How big will the battery need to be to run a four to five hundred kilowatt combine 24 hours a day for a week? Do the sums.

84,000 kWh. Or, say, 1,000 Tesla batteries. An extreme example of where electric isn't viable yet. Let's put combines to the bottom of the pile, and concentrate on passenger vehicles, then.

Herzlos

Car_54 wrote: »

Apart from the problems that others have already pointed out, the low speed is irrelevant. A combine is effectively a mobile factory - cutting, threshing, sieving, chopping, etc. That is where most of the energy is used, not in simply moving the machine around.

Similarly, a tractor needs the capacity to power other machinery in addition to moving itself from A to B.

Unless I'm wildly mistaken, factories have been using electricity for decades.

The only 2 issues with electrification is:
1. The huge power draw
2. The long run-time without being able to dock.

1. Just requires huge batteries. Adding 2t of battery to something that weights 40t, has a top speed of 4mph and already costs half a million quid isn't going to be that big a deal.
2. Recharging on the fly either means cables (it's covering a single field at a time in stripes, so it's not going to need miles of cable, a few hundred ft would cover it most of the time) or having something follow it to recharge.

Combines and tractors are also vastly different beasts. There's a lot of farm equipment that's a tractor or smaller that is used fairly infrequently, within a couple of miles of the shed it lives in. They'd be ideal candidates for electrification.

I didn't say it'd be easy (you can't just pop a Tesla battery in a tractor), but I'm pretty confident that we could come up with a workable solution with a bit of effort.

What are we going to do when the oil runs out?


For the record; I think we'll see small plant being electrified in the near future (bobcats, loaders, diggers, small tractors), and that combine harvesters will be about the last things left running diesel in 25 years.