Emissions resulting from farm power
Unlike many other challenges the mankind faces in the process of
advancing its life on this Earth, climate change is too complex a problem first
to understand and then to find solutions. Every country - rich or poor,
developed or developing – strives to protect, enable and nurture its farming
community with appropriate policy interventions and economic incentives. But,
the very same nation state is hard lined about anything that compromises its
environment, ecology and eco – systems. These essential elements are non –
negotiable in the eyes of every nation state owing to their indispensable
nature in creation, sustenance and evolution of life forms on Earth. While the
demand for power on the farm has been on the rise globally as more and more
farmers shift towards mechanized farming, there is a corresponding rise in the
quantum of emissions resulting from the use of fossil fuels for powering
agricultural tractors. The alarm bells are ringing louder and clear for
everyone to pull the socks and gear up for the ever stricter emissions
regulation. Therefore, it is imperative to develop, transfer and adopt greener
technologies that leave a smaller carbon foot – print and helps to promote
sustainable agriculture.
Hybrid power systems
Utilizing the synergy arising out of combining power systems having
distinct characteristics, the engineering community is attempting to redefine
and change the landscape of mobility solutions forever. In automotive parlance
this synergistic combination is called a hybrid. Attempts were underway for
over a century now to build and use hybrid power systems with the earliest
attempt dating back to circa 1899. The earliest known hybrid was an electro –
muscular hybrid which uses an electro motive force in combination with human
muscular power. In pursuit of finding new and efficient solutions, several
innovative hybrid combinations emerged with passing of time. The most widely
known hybrid being the petro – electric hybrid which uses a petrol powered
internal combustion engine in combination with electrical batteries for
mobilizing the vehicle. Other well known hybrids include petro – hydraulic, petro
– pneumatic and chemo – electric hybrids. The chemo – electric hybrid is a
combinatorial use of fuel cells with electrical batteries for propelling a
vehicle. Several automotive manufacturers across the world have successfully
built hybrid passenger vehicles and the most iconic among them being the Prius
from Toyota . Although
the technical know – how on hybrids has evolved significantly over time, there was
no convergence which in effect prevented the migration of hybrid related
technical know – how from passenger vehicles to be used in off – highway
vehicles. Besides, the power demand characteristics of a tractor are
significantly different to that of a passenger vehicle which calls for newer
solutions.
Agricultural tractor and its power characteristics
An agricultural tractor is a versatile machine and an important
source of power on the farm. Although tractor per se has limited utility on the
farm, the versatility of this machine lies in its ability to carry and operate
a wide range of farm equipments in order to perform various agricultural
operations which includes but not limited to soil manipulation, seed drilling,
crop care, crop harvesting and grain transport. Performing any of these
operations on the farm requires a source of power which in one form is an
agricultural tractor of a specific power rating. Selecting a tractor of a
particular power rating is a function of the kind of agricultural operation to
be performed, specifications of the farm equipments to be used for performing a
given agricultural operation, size of the land holding, soil conditions and
desired operational time for performing a given operation. For a given power
rating, the one factor which distinguishes a tractor from a passenger car is
the torque generated in the final drive. Tractors are high torque machines and
this particular characteristic is advantageously used for leveraging tractor as
a source of power on the farm. Also, in contrast to a passenger car, the power
output of a tractor must have to remain high and constant for a prolonged
period of time in the course of performing a given agricultural operation.
Tractors with hybrid power systems
Tractors with hybrid power systems as a concept is gaining momentum
in the last couple of decades. As a conventional approach, the engines are down
sized or down rated and the corresponding balance in power is supplemented by a
suitable electrical means either in the form of a battery or an electrical
motor operationally coupled to each other. The fundamental advantage underlying
a hybrid machine is the minimal transfer losses involved when the power is
transferred over wires or cables as against the transfer of power by means of
mechanical drives. A multi – faceted approach is taken to explore and deduce
hybrid solutions keeping in mind the need to generate and maintain constant
power for a prolonged time interval. One of the most widely accepted hybrid solutions is the use of hydraulic
power in combination with motive power of the engine. Yet another known
hybrid technology involves switching the type of input fuel for the engine
depending upon the external load requirements. The major players in the global
tractor market have started taking patent positions in the field of hybrid
tractors. A shift from a conventional engine based power system to a hybrid
power system in a high torque machine like a tractor calls for significant
changes in power generation, regeneration, transfer and use and many of these
technically novel changes are patent protected. For example, Case New Holland
(CNH) claims an arrangement of at least two electrical machines in a structural
casing defining a transmission which is operationally coupled to an internal
combustion engine of a hybrid power train in its patent EP1317050 B1. Another
important technology from AGCO which is worth noting in the field of hybrid
tractors is known through the patent publication US20130047753 A1 which claims the
partial or full operation of the power take off by electrical energy from
battery.
Need for sustainable farm power
Tractor will continue to remain an indispensable machine on the
farm. With the increased relevancy of farm tractor in modern agriculture there
is a corresponding increase in its use and adoption which has a direct bearing
on the emission of noxious gases. There is an immediacy of purpose for
appropriate technological interventions to check the growing menace of on the
farm emissions. Agriculture being existential in nature for the mankind to
survive and prosper, it is essential to adopt sustainable farming solutions
which will create reliable and stable bio – systems for the generations to
come. As they say, there is no culture without agriculture and one right step
in this direction to create a sustainable foundation for agriculture is the
development and adoption of environmental friendly technologies like hybrid
power systems in tractors.