https://www.youtube.com/watch?v=pTDxMZfj6yk" rel="nofollow - https://www.youtube.com/watch?v=pTDxMZfj6yk

The author's explanation of the tractor pretty much proves why it didn't sell:

Fit and finish appears very professional...

It boasts considerable tractive effort...

It's comfort issue (seat) was resolved, albeit not immediately

But it's major faults seal fate:

PTO operation is crippled by design- if you want 540rpm PTO, you have only 3 ground speeds, and only one operates at a working speed.

Run time between charges at a PTO load is 1.5hrs.  Entirely useless for tractor work.

Hydraulics are slow.

It doesn't matter how quiet, comfortable, pretty, or 'environmentally concious' it is, if it WONT DO WORK WHILE THE SUN SHINES.

What do they do?

Fix the capacity problem.  No less than 13 hours' full work time between recharges, OR... Make it charge in under 5 minutes.  (5 minutes is how long it takes to refill a fuel tank).

Fix the road-speed/work speed/PTO problem.  Independant PTO motor, variable speed traction motor.

Higher-capacity hydraulics EVERYWHERE... including steering (just in case they overlook that).

Clearly, one of the design weaknesses is evidenced by the hydraulics-  they're running constantly, that's the whine.  They don't need to, they need an accumulator, a sensor, and detector switches on the valving.  That'll reduce battery burn, too.

Their website is still operational, maybe take a look before it goes away.

http://solectrac.com" rel="nofollow - http://solectrac.com   

Splashing across the homepage is announcement of California 

subsidy for going green. The CORE program. Gotta love that Cali place.

The little tractor had just a 24KWH battery. Too small

to be practical. Also the voltage was just 72V. I wonder if the relatively low voltage

is a safety measure for farmers and their mechanics.

They would need to fix all Dave talks about. As far an I know, the electric forklifts in

widespread usage don't suck up power when not moving or lifting. But they do use (on-demand) hydraulics for the lift and steering. Many still use lead acid batteries.

DaveKamp wrote: ..Clearly, one of the design weaknesses is evidenced by the hydraulics-  they're running constantly....

That's just dumb

LeTourneau didn't use any hydraulics; of course they have a big diesel engine running a monster generator putting out something like 600 VDC They are popular in the sawmills around here because they can lift a truckload of logs in one bite.

Yes, Louis- you're right-  from the field, with a fuel truck...  but even my Kubota BX, which although it doesn't have the battery weight to help generate the electric's drawbar FORCE, is significantly capable of more work, both PTO and hydraulic, because it's 6ish-gallon diesel tank will run it full-snot for every bit of 8 hours, and I can put another 6 in it from the trunk of a car in that 5 minutes, and be on for another 8 hours.

It all comes down to energy density.  A 24kw/hr electric battery system weighs around 500lbs, and the electric traction motor, driveline, and electronics for that setup come to about 1000lbs... and if you run it AS a 24KW (32hp) drive, you'll be at full discharge in one hour.  16hp in two... but you're best off not running that battery below 25%, lest it's service life go to heck, so that means you're looking at 8hp for 2.5hrs before a charge.

The BX-1800 in my driveway will run at 18hp and no matter how fast I empty the tank, a refill brings it right back to where it was.  6 gallons of diesel equates to 720,000btu/hr or 211kw/hrs per tank.  At 10% efficiency, that's 21kw/hrs of mechanical power... so one 6gal tank is significantly more energy, in only 42 pounds of weight.

The electric tractor simply cannot beat that empirical reality.