Electric tractor

[danie]

Can anybody comment on electric tractors . If you use an electric tractor to plant corn for instance and generate the power by solar and wind can that qualify for carbon credits.

If you compare biodiesel with electricity generated by wind and solar you will use a much smaler portion of land to generate your energy needs.

[cameron marical]

ive never really heard of the idea of an electric tractor, but i love it. as for you q about carbon credits, of course, you will drop in carbon output substantially compared to normal gas hog tractors.

[CaptainPanic]

To the second question: yes. Wind power and also solar will require less land area to generate the same amount of energy, although it's a different kind of energy (electric vs. chemical).

 

Whether you can use that in a tractor depends on the size of the battery I guess.

 

I've never heard of an electric tractor myself... but I do remember the previous thread that you started on the exact same topic (click here for link). So allow me to link to that, so that everybody is updated again with the previous discussion. Especially the last post seems to make sense.

[danie]

Thanks for reminding of the prevous thread. I almost forgot about it. Maybe it will be good to explain what I am trying to demonstrare.

 

I want to show that it possible to produce food without fossilfuel. (As in the past with horses and donkeys) So started to produce Biodiesel from and and used that for planting etc. The problem is that you use 10 % of your land to produce fuel ror the other 90 %.

 

I then came up with the idea to use electricity instead of diesel. The electricity can be generated on land that are not used for crops (and less area)

 

I build a small tractor with a 10 kW forklift motor. It has a little plough , rotovater and planter.

 

The batterys are charged by a wind turbine and solar panels.

 

I am now trying to determine the economics of the process. Carbon credits could be an aded bonus.

 

I am also looking at ways to fix nitrogin with plasma (by sending air through a plasmacutter and pump the ionised air through water )

 

If anybody are interested I will make theresults availeble.

[CaptainPanic]

I am interested

 

I'd like to see the results, and if you want I can give some feedback. I applaud the initiative, but I'm skeptical about the financial side of it. I really hope that it can work. I work in the field of sustainable fuels (bio fuels, but not biodiesel)... I consider myself as part of the "good guys" here... I'll be trying to help you.

 

The more info you post here, the more feedback you will get. Of course you can also just ask questions.

[DrDNA]

I am also looking at ways to fix nitrogin with plasma (by sending air through a plasmacutter and pump the ionised air through water )

 

If anybody are interested I will make theresults availeble.

 

That's quite interesting.

Re; the tractor. Are you using the standard fork lift batteries?

 

RE: Nitrogen. What form(s) of nitrogen are you trying to fix (eg, ammonia and/or nitrous oxide)?

What is the overall objective?

 

How much power/mole nitrogen fixed does it require?

 

Could you post the chemical reaction that is involved in your nitrogen fixation process?

 

Thanks!

Edited February 14, 2009 by DrDNA

[danie]

Lets try some basic calculations on the economy of the electric tractor:

 

5Kw windmil $ 8000

10 x 200 W solar panels $10000

Regulater and batterys $ 2000

 

Total $ 20 000

 

The tractor costed about $ 3000 to build.

 

With a one row planter at 6 Km per hour and 1 m between rows I can plant between 2 and 5 ha per day. I use 3 battery banks that I can change. The batterys is also charged owernight when the wind is blowing.

 

To plant the same are using a diesel tractor you would use about 20 liters of diesel .

You can now use the interest rate and diesel price in your country and do some comparisons. Also allow for a rise in the oil price and take the value of carbon credits into acount.

 

NITROGIN FIXATION

 

I am not sure of the reaction. maybe somebody can help.

[CaptainPanic]

If you plan to use the tractor 10% of the time... and you have enough batteries to store ALL the electric power from the solar panels and windturbine:

 

A normal tractor has a 15 to 480 kW engine.

 

You have designed 7 kW of power (electric), to be used 1/10th of the time. Therefore 70 kW is available during tractor-operation. We can assume that an electric system of 70 kW will have the same results as a 140 kW diesel engine (because internal combustion engines aren't very effective, and produce a lot of heat - same reason why electric cars are more efficient).

 

So, we can conclude that you are not thinking about the smallest of tractors, it also is no monster (probably not suited for mud or clay). If you plan to use it more than 1/10th of the time, you'll have a smaller engine.

 

20 liters of diesel

But I want to show another type of comparison. You use 20 liters of diesel. That is the equivalent of 20 * 44*10^6 J (1 liter of diesel is 44 Megajoules). The total is 880 MJ.

 

To generate that same energy with the wind turbine and solar cells (total 7 kW, or 7000 J/s), you need to run them for:

880*10^6 / 7000 = 125700 seconds, which is 35 hrs.

 

Since the wind is not always blowing, and sun shines only half the time, we probably should double that... and half it because electric systems are more efficient. So: recharge time is 35 hrs.

 

 

Of course, these are crude calculations. Did you check the weight of a battery bank? If you plan to replace them (manually?) you'd better check how many kilograms of batterypack need to be replaced.

[DrDNA]

danie,

How does the plasma cutter/nitrogen fixation thingy work and/or what made you think of doing it that way?

Are you trying to fix ammonia and/or nitrous?

[danie]

I dont know if the plasma cutter thing will work. As you know in nature nitrogin is fixed during thunder storms. A I understand it the lightning ionises the air mulecules whitch then recombine in other molecules including NO x

Thats why plants always grow better after a thunder storm.

I a plasma cutter a stream of compressed air is passed through a nozzle in which the air is ionised in a plasma. The ionised air stream is then used to cut through metal.

 

I think that if you bubble the ionised air stream through water that water can contain some fixed nitrogin . How much and in what form I dont know.

 

As you have correctly calculated you only use the electricity for 30 days during the planting season.

 

The idea is to use the electricity to make fertiliser during the period in which it is not used for planting crops.