theluckycountry wrote:Covid is the De-growth plan, as I have said before.
vtsnowedin wrote:Covid is a pretty poor degrowth plan as it kills mostly elderly people well beyond their child bearing and child raising years. Our economies will learn how to live with covid and it will not be a long term drag on business profits.
Actually I am surprised that governments around the world have let it disrupt them anywhere as much as they have in light of how little the lockdowns actually accomplished.
With tractors they would have to carry monstrous battery packs, extremely heavy, most likely need to change for a fresh pack every hour or two, and have the capacity to charge them over night.
Newfie wrote:VT,
While I agree with most of your post except the bit about plowing with electric tractors.
I see guys trying to come up with electric sailboats, it is not working except in very constrained applications. They are limited to very little motor use, noting like the range and speed of even a smallish diesel.
With tractors they would have to carry monstrous battery packs, extremely heavy, most likely need to change for a fresh pack every hour or two, and have the capacity to charge them over night. So if you are going to do it with solar then you need some storage medium; more huge stationary batteries or flywheels.
We have electric trains, but they run in HVAC overhead contact wires. 13kV and up.
Coal gas I could see, not electric.
vtsnowedin wrote:There are a lot of falsehoods in your post. Prices are up but demand has not dropped. Air passenger flights are up not down. Cars last fifteen years now not five. And we will never revert to plowing fields with oxen. Battery powered tractors charged by solar panels at the edge of the field or a couple of wind turbines on the next high ridge perhaps but never back to draft animals. Get real.
vtsnowedin wrote: I think you are off there. A Tesla model Y battery holds enough energy to take the car 326 miles so is equivalent to 10 gallons of gas or about 8 gallons of diesel. Remember that ice engines are only about 33% efficient and straight electric are above 80%.
Now my 45 Horsepower diesel tractor can do quite a bit of work with eight gallons of diesel and the big Ag sized 150 HP powered ones actually do more per unit of fuel burned so replacing that big diesel engine with electric motors and the battery packs to power it all day should not be a problem.
theluckycountry wrote:vtsnowedin wrote: I think you are off there. A Tesla model Y battery holds enough energy to take the car 326 miles so is equivalent to 10 gallons of gas or about 8 gallons of diesel. Remember that ice engines are only about 33% efficient and straight electric are above 80%.
Now my 45 Horsepower diesel tractor can do quite a bit of work with eight gallons of diesel and the big Ag sized 150 HP powered ones actually do more per unit of fuel burned so replacing that big diesel engine with electric motors and the battery packs to power it all day should not be a problem.
There is a big difference between a car with high tire pressures cruising down the blacktop and a heavy tractor moving through loose soil, hauling a plow in the dirt behind it. Your back of the envelope calculations explain nothing I am afraid.
Newfie wrote:Quick look up, I will calculate as I type, lets see where this leads.
A Telsa Y has 75kW battery capacity. So, for easy math lets say this is 10kW for a gallon of gas/diesel.
I have 2 each 300W solar panels, the very best I have done with them is a bit over 1kW (each) in a whole day, clear sky, tropic sun. They are +5’x3’ or over 15 square feet each. I need 10 to make 1 gallon of diesel equivalent.
So that is 150 square feet for one gallon of diesel. 1,500 square feet for 10 gallons.
And that is in perfect conditions. You will typically need much more than that because you are in Vermont and can’t count on sunny skies when farming. So you need to capture and store enough energy to keep your tractor running when you are not using it. I am guessing you may need storage of something like 10 to 20 times the daily fuel consumption to assure success. Lets assume 10.
So you will need the equivalent of 10 Tesla storage batteries to act like a diesel fuel tank. And then you need to charge those batteries FAST when the sun does shine. So you will need something like 5x the solar array for sufficient recharge.
That works out to 7,500 square feet of solar panel and 10x Y type battery banks for storage. And that may be conservative.
It all depends upon 2 things.
1-How important is it for you to plow/seed/till/harvest your field TODAY or THIS WEEK.
2-What are the consequences if you don’t have sufficient power? Does your family starve?
I watched a guy rip out a perfectly good diesel (about 40-50hp) and install an electric motor with a big battery bank and a small charge diesel. Then he went for a couple of month cruise to see how it worked. When he came back he ordered a 36hp diesel to charge his batteries to run his y motors. Why? Because it quickly became evident to him that he could never STORE sufficient electricity to meet his needs for a safe passage. And this is what diesel is; super dense and stable and light energy storage.
theluckycountry wrote:As for solar tractors doing our farming, well that's just a delusion, how are are you going to build them and replace the mammoth batteries without a cheap oil based economy?
luckycountry wrote: I see the roads have lots of electric cars, where are the electric trucks?
Newfie wrote:VT,
That 1kW/day was in the tropics, sun overhead, in near perfect conditions. You will be very lucky to get 15% to 20% of that on average in VT. Summer somewhat better. Winter worse.
Wind, even in the trade winds, is a fraction of solar.
I use both.
Return to Conservation & Efficiency
Users browsing this forum: No registered users and 4 guests