Solar power

[oil pan 4]

Originally Posted by roosterk0031

I doubt any farms have the service to charge at that rate. 200a single phase is the most common service. 350,000/240 = 1,458 amps. I'll stand by my statement that ethanol, even in BTU negative will replace diesel for Ag use before batteries. Cummins has already developed the engine.

Farms around here have 3 phase 480v power to support running 100hp deep well pumps.
Even my place has 480v service. It was only for a little 20 to 25hp pump, the transformers are not hooked up to the overhead lines.

[redpoint5]

Farms would have DCFC service if they had battery equipment. We're not talking about using battery tractors now, with existing infrastructure, we're talking about the future when such a thing might exist, and the practical infrastructure that might support it.

Originally Posted by aerohead

I noodled some numbers for the Caterpillar LEXION 500-Series.
*I gave it a thermal efficiency of 45.9% (near-continuous,constant-rpm )
*Allowed 136,775.23 Btu's/gallon diesel
*divided by 3414 Btu/kWh to get an equivalent electrical input commensurate with the diesel's actual net output to the harvester's machinery
*and came up with approx. 116.683 kWh/hour load.
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If we're looking at an autonomous,GPS-facilitated unit,operating continuously,24-hrs/day,we'd be looking at around 2,800 kWh/day.
A towed,'AG-PACK',2-wheeled trailer 'tender',with 5-Tesla Powerwall-2 units,At 3,701-pounds would suffice to provide enough power.
One operating,and a second,which with a 350kW charger,would come to charge in 8-hours,during off-peak demand,at discounted pricing incentive.Or during mid-day solar farm peaking,when renewables may have to be curtailed,due to insufficient demand,as is experienced in San Francisco,California' summers,where they lose about 850-million EV miles equivalent.
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The numbers may be a bit loose,but hopefully in the ballpark.

Yeah, but where did you derive the average power/fuel consumption? That info isn't readily available as far as I can tell, and I can only find peak HP specs from manufacturers. That's not a useful metric since equipment is rarely at peak power output.

I had browsed farming forums to see what farmers were reporting for diesel consumption per hour. It was low enough that the equipment could run for days without refueling.

I'd like to see more of the work shown if you don't mind.

[roosterk0031]

Did a little searching on the web. Combines run about 250 hours per year, generally about 1 gallon per acre or 15-20 gallons per hour depending on Corn or soy beans. Off road diesel is $2.40, off road (before road taxes if they make such a thing) E85 is $1.49.

The lowest primary distribution voltage is 2300 volts, so that would over 50 amps per phase, throw that over every farmer trying to do the same thing and the system is going down. Alliant my provider has shut down 3 coal plants in the last few year, broke an agreement with the only nuclear plant in iowa making it shut down earlier than planned and installed some wind mills but are asking to up our rates by 25%.

A surge in capacity like that is better served with a liquid fuel even if BTU expensive.

The closest wild mills are 6 miles north and 2 west, this morning not one was moving. I can see 20-30 when I hit the high spot south of town.

[JSH]

I have a crazy idea that might work. Instead of trucking 1/2 of our corn and soybean crops to feedlots we could put the cows in the field and let them eat grass. Seems much more energy efficient.

[freebeard]

Okay, so long as there is a way to add seaweed to their diet.

[sendler]

Originally Posted by JSH

I have a crazy idea that might work. Instead of trucking 1/2 of our corn and soybean crops to feedlots we could put the cows in the field and let them eat grass. Seems much more energy efficient.

The production will be much less for the time to market and the human labor input raising the price. But we can get by with much less red meat. And just go back the amount of cattle and cows that can graze on the hillsides which are not suitable for trying to grow crops on.

[NeilBlanchard]

Originally Posted by JSH

I have a crazy idea that might work. Instead of trucking 1/2 of our corn and soybean crops to feedlots we could put the cows in the field and let them eat grass. Seems much more energy efficient.

Cows get literally sick when we feed them soy and corn. They have 4 stomachs and they evolved to eat grass. Grass fed cows are not only healthier, they can help sink carbon into the soil.

[freebeard]

(https://ecomodder.com/forum/showthre...tml#post595591)

I haven't consumed much beef since the Mad Cow stories started.

I worked for a feed & seed company in the 1960s. The owner's son came back from Oregon State University with the idea of adding bone meal to the cattle feed.

Today we know that the bone meal contained ground up brains. He and his brother spent a lot more time breathing air with bone meal dust in it. Today they have serious neurological problems.

[aerohead]

Originally Posted by roosterk0031

I doubt any farms have the service to charge at that rate. 200a single phase is the most common service. 350,000/240 = 1,458 amps. I'll stand by my statement that ethanol, even in BTU negative will replace diesel for Ag use before batteries. Cummins has already developed the engine.

I chose this value,as Volkswagen's new charging infrastructure is rated at this delivery rate,and considered that in the near-future,that this would not be uncommon.
When I farmed in West Texas,3-phase power was available.The landscape was dotted with oil well pump jacks,which all ran on 3-phase.
I wouldn't be surprised about ethanol-powered tractors.That was Henry Ford's original vision.

[aerohead]

Originally Posted by redpoint5

Farms would have DCFC service if they had battery equipment. We're not talking about using battery tractors now, with existing infrastructure, we're talking about the future when such a thing might exist, and the practical infrastructure that might support it.



Yeah, but where did you derive the average power/fuel consumption? That info isn't readily available as far as I can tell, and I can only find peak HP specs from manufacturers. That's not a useful metric since equipment is rarely at peak power output.

I had browsed farming forums to see what farmers were reporting for diesel consumption per hour. It was low enough that the equipment could run for days without refueling.

I'd like to see more of the work shown if you don't mind.

Oilpan4 threw out the fuel consumption value,so I just ran with that.
In the past,the SAE Papers have written such that,for instance,an automobile manufacturer will use gearing to limit top speed cruise to 80% of bhp-rated power,as you might do also in an aircraft.
If so,then we can take 80% of the bhp as the running power as an estimate (that's all mechanical engineering is good for,lacking published data,or a dyno)
We know the chemical energy potential of the fuel.It's published.
A range of thermal efficiencies are also in the literature,which imply BSFCs.
*With a 462-bhp engine,at 80% load,we'd have a available,constant,396.6-hp.
*With a thermal efficiency of 0.459,the diesel loses 54.1% of the fuel's energy before any useful work can be done.(it takes 1006.53 hp worth of diesel to produce 462-bhp at the shaft)
*An AC induction or permanent magnet motor may have a 98% mechanical efficiency,so it doesn't need as much 'fuel' as a BEV,compared to an ICE.
*On an hourly basis,I figured that an electric motor consuming 116.683 kWh can do the same work as the diesel engine.
*A Tesla Powerwall-II is rated at 200-kWh.
*14-Powerwalls in a trailer would cover 24-hours worth of continuous operation,as per oilpan4's requirement.
*14-Powerwalls weigh 3,701-pounds.(a 1980s full-size pickup truck)
*In a trailer with 2-flotation tires,we might expect an all-up trailer weight around 4,200-pounds.
*Run an umbilical cord between trailer and equipment.
*Or,special batteries could be incorporated inside the wheels,and provide the ballast as well.Import/export the power through slip-rings at the hubs.
*One trailer would do a day's work,while another charged in as little as 8-hours,with Volkswagen's equivalent capacity,with 480-VAC,3-phase utility power.
*The grid power could be renewable,so zero-carbon.The whole point of the exercise.
I can't think of anything else to add.Let me know if I've muddied the waters or not.