June 20, 2010

Energy Conservation through Farm Tractors

-By Mansoor Rizvi (This article is based on the study conducted as an Agricultural Field Engineer, 1989-1991 with RCG/Hagler & Bailly, Inc., (USAID Project) Islamabad. Currently, the author is working as a Consultant with CaseNewHolland).


ractor rear tires were found to be over inflated by 20-22psi. Study suggested adjustment of tire inflation pressure to the recommended level that is 12-14 psi. This will bring the tractor slip in the range of 7 to 11% in unplowed fields and 10-15% in plowed fields compared to 12.5-16.6% in the unplowed field and plowed field respectively

The agricultural mechanization history of Pakistan has witnessed a tremendous growth in population of tractors in the recent years. The total industry volume has now reached to 73,000 tractors in 2009. Up until 1995-2004 the average sale of tractors in Pakistan were not more than 15,000 tractors.

The progress made in this field speaks in volume about the technological advancement attained by present vendors and tractor manufacturers. This has enabled Pakistan to produce 90% of the tractor parts within the country.

Success breeds numerous challenges and responsibilities. The scope of this article is to briefly touch the energy conservation aspect in tractors that is going to be our immediate challenge in the near future. There is a dire need to execute the energy conservation plan outlined in the study conducted by National Energy Conservation Center, Islamabad in 1988-1990. This will not only bring enormous saving in the diesel fuel but will enhance the life of tractor, increase productivity and help in saving the environment.

There are several methods to conserve energy; it could be accomplished by introducing zero or minimum tillage techniques and by switching to fuel-conserving diesel tractors. Both of these methods require a major overhaul which demands lots of money and resources while the one proposed in the above study cost nothing except to build a strategy to ensure that tractor operators be trained properly.

In year 1989-90, USAID and National Energy Conservation Centre (ENERCON) jointly run a project to study simple methods of energy conservation through audit and retrofit of tractors and tube-wells in Pakistan. This project has particularly introduced an extremely cost effective and simple method of energy conservation in tractors.

Unfortunately, this project met the same fate as any other project in Pakistan. It was shelved just after it was ended in mid 1990s. Although the entire study concluded with a very simple solution to save energy by training the tractor operators on the proper use of tractors but the economic and environmental impact mentioned therein was tremendous.

A paper was presented by Rizvi, S.M. and G.S. Saqib in 1992, titled “Tractor operational retrofits for saving fuel in tillage at the International Energy Conservation Symposium”. This was organized by ENERCON, PERAC, and ENAR Petrotech Services held at Islamabad, dated April 25-26. The main points of the study says that just by improved operators’ skills 21% saving in diesel fuel and 19% saving in time is possible. This study did not include the repair and maintenance aspect.

The mathematical analysis was done to transfer this saving in terms of litres and cost of diesel fuel indicated that on a national level 254 million litres of diesel fuel worth 1286.2 million rupees (the diesel cost was Rs5.05/ litres when this study was conducted) could be annually saved by simply training the operators to optimally use the tractor during the tillage operations.

They reached to above numbers by considering the following factors:
1. Total number of tractors in 1988-1989 (238,000).
2. Average annual tractor use (894 Hrs/annually).
3. Average fuel consumption derived from the field energy audit of tractors (5.7 l/hr).

On the basis of the above data the paper indicated that 1.3 billion litres worth 6.55 billion rupees were consumed during tillage operations in 1990-1991. The study also predicted an annual growth of 77.4 million litres of diesel fuel due to the increase in the number of tractors which was projected to be 15,200 units annually at that time. To bring the above saving in diesel fuel; operational retrofits and operator training were suggested which are as follows:

Tractor rear tires were found to be over inflated by 20-22psi. Study suggested adjustment of tire inflation pressure to the recommended level that is 12-14 psi. This will bring the tractor slip in the range of 7 to 11% in unplowed fields and 10-15% in plowed fields compared to 12.5-16.6% in the unplowed field and plowed field respectively.

Farmers were found operating their tractors in low gears which resulted in low average speeds (5.9 km/h) against recommended speed of 7-9km/h. As a result fuel efficiency was also found to be very low. Gear up/throttle down strategy was advised in the study to optimize fuel efficiency and productivity (It is suggested that engine RPM should be kept 80% of the rated engine RPM during ploughing while the selection of gear, High-1 or 2, be used to increase the speed of tractor not engine RPM. e.g. MF-240’s rated RPM is 2250 RPM. As per study during plowing it should be 1800 RPM while using 9-tine cultivator). National Energy Conservation Center had issued very descriptive fact sheets in Urdu for Pakistani Farmers.

This article is an attempt to divert the attention of Government, in the light of the study conducted by ENERCON, to execute a nationwide energy conservation plan to save energy through agricultural tractors. This will bring a change in the overall economy and environment of the country.

There is a need to devise certain policies to make sure the tractor operators or people responsible to operate tractors should have a valid permit to operate a tractor. This permit or license should be issued by a designated agency issuing the certificate after providing them proper training and awareness of energy conservation as outlined in the ENERCON study.

Even though, we have this study available that could help us save millions of litres of diesel fuel saving millions of dollars, we have not done anything so far, and thus, have miserably failed in the attempts to make Pakistan prosper.

In the end, just view these numbers in the current scenario when the price of Diesel has reached to Rs.72 per litres compared to when the referred study was made (5.05Rs/litres) and the annual sale of tractors has gone up to 60,000 tractors per annum.

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