Why don't they make one (with good rechargeable batteries) so it's covered in solar cells (where the mud doesn't land) and is designed to be left sitting outside 24/7?
There's just not enough surface area, and much/most of it isn't going to be at the optimum angle to absorb solar energy anyway. IIRC there is 733 watts per square meter of energy coming from the sun at the equator at noon on a perfectly clear day, and current solar technology is only 20-25% efficient, so you're looking at more like 150-180 watts per square meter. That's why it's far better to have a fixed solar install that has more surface area and can be placed in an unobstructed area. Really, the best thing we'll probably ever have is the flexible roll-up solar panels that can easily be hauled somewhere and laid out.
Ok -- I have two questions -- Why would anyone want one? What problem is this trying to solve?
The electricity is still coming from fossil fuels (natural gas, coal), nuclear, some hydro, and virtually no wind/solar.
You're assuming I'm doing this for environmental reasons. Not so... I want a more reliable, quieter tractor, with fewer moving parts.
It's pretty inefficient to transmit that electricity and then charge a battery repeatedly. If you drop all the lop-sided government subsidies, it costs more to "fuel" an electric tractor than a diesel tractor.
Gasoline engines are in the 25-30% efficient range today. Diesel is better, but still only 30-35%. An electric motor is about 90% efficient. In addition, my house can be my fueling station, so I don't have to run out and fill cans any more.
It will only run for a few hours and then needs to take a long rest while it's being charged. Diesel can run nonstop around the clock.
That's all I need it to do. If it can do 2 hours under a load, it'll take care of 95% of my needs. If it can do 4 hours under heavy load, 100% of my needs. Then, it can sit overnight and charge. In fact, it'll usually have several days to charge in between.
I can't carry fuel to it. If it quits, I can't pour a gallon of electricity into it to get it back to the barn.
So don't run it out. In a real pinch, a generator or an extension cord might do the trick, but it's better to just not run it out.
We already have a power grid that's FAILING in many locations during extreme weather. Why would we want to add additional load that has more efficient fuel options? (Just wait till they start trying to charge EV semi-trucks, etc. )
That is easily handled by charging at times when the power grid is underutilized. Currently, overnight is the lowest usage on the grid. More solar would obviously change that equation, but it's very easy to avoid peak times. Every EV can be programmed with your utility's off-peak times to take advantage of time-of-use charging, and there's plenty of smart chargers as well. Finally, with V2L technology, EVs can be used to help the power grid in extreme conditions.
Despite the fact that the government will likely steal some more of our tax dollars to offer obscene subsidies, the true actual cost is higher than diesel. If it costs more and doesn't solve any problem, what's the point?
They should be simpler to build once companies figure out how, and with far fewer parts and far less vibration, maintenance costs and time should be much lower. Plus, it'll be nice and quiet. Those are all really good things in my book.
The free market should drive innovation and product development. I just can't see how this makes engineering sense or economic sense.
There are things that can be done with battery weight that could be very helpful with tractors, and that's the kind of engineering I'm interested in doing.
The only way I'd maybe and that's a big maybe go near an electric vehicle is a hybrid and then the chances of me even go that route is next to nil. The cost of replacement batteries, the life of them makes it seem , to me anyway, a fools choice and that's just my thoughts.
The whole battery replacement thing is largely overblown, thanks to lots of FUD spread by the fossil fuel industry. The battery on my car is supposed to still have 80% capacity at 750,000 miles. It will outlast me. In addition, most batteries are made of several modules that can be replaced individually in the event of a serious fault. I have literally zero worry about replacing batteries.
I've always used this scenario as an example.
Say I have a 50km round trip to work every day so that's 250kms a week, say 300 for round figures. Friday night something happens and I have to go out on a 50 km trip but since I only charge the car once a week so I don't ruin the battery, I can't go as the battery is almost dead.
That's not at all how it should be done - You should plug it in whenever you're not using it, and let the battery management system take care of things. That's one of the things I love about electric cars - You leave the house with a full "tank" every day, and you never have to go out of your way to charge it, or stand out in the cold waiting for it.
Same timeframe, we have a storm go thru and the power goes out for 30 hours which it did just a couple months back. How do I even go out for necessities?
You just go, because it was probably already fully charged before the power went out. I have a friend whose house is set up where he can power his essentials from his car in the event of an outage - For days!
I question the APPLICATION of the technology. I don't dislike it. "The right tool for the right job" doesn't equate to an electric tractor (except in the most unusual situations).
It would work great for me, a homeowner who needs it to work for a few hours a week, and be reliable and quiet. And I don't think that's particularly unusual.
Many of the Hardy's are spread around the midwest but I don't necessarily have a grasp on the extended roots of our tree, so there is a possiblity but not one I can confirm... I will say however, all the Hardy's I know are good hard working folks, so hopefully I can stand in the good company of Dave and Pam Hardy! 
