Polin Kumar Saha :
Bangladesh is a country of agriculture-based economy where almost half of the country’s population is directly involved in agriculture. In ranking of world agricultural production, Bangladesh has to be proud of its amazing success in the agriculture sector, which plays an important role in the country’s rising economy. However, farmers usually use irrigation pumps to supply adequate water for their crops where fuel based traditional irrigation system is still popular with most of the farmers in the country’s agriculture. Based on the World Bank information, Bangladesh spends $900 million every year for 1 million tons of diesel to run its irrigation systems. It is a huge demand of fuel in our irrigation system which is obviously not an environment friendly demand because of its releasing greenhouse gases to the atmosphere. Over the period, technology has been changed dramatically in the irrigation scheme of Bangladesh. In the last few years, farmers are moving to the solar based irrigation pumps in different parts of Bangladesh, since the cost of diesel pump is higher compared to the solar pump – as the major considerable point to them. But, this innovative irrigation system is executed not only for the matter of costs to purchase diesel fuel, but solar-powered pumps are a realistic choice in the context of sustainable agricultural practices – as it is a global demand in renewable energy technology, protect the environment and reduce the consumption of inadequate earth resources.
During the peak season of irrigation, about 20% of our total produced electricity is used by the farmers. As a result of this, there is becoming a situation of supplying shortage of electricity in many areas of the country, especially at the time of irrigation period. If we consider for our long term benefits with the electricity demand and supply, switching to the solar based power pumps can promote us to access more electricity without an interruption of power supply sometimes- sustainability benefit in context of electricity for all (social benefit). On the other hand, the burden of government’s ability to produce electricity will be decreased, and consequently, the overall cost of fuel based electricity production and pollution will be reduced gradually – sustainability benefit 2 in the context of economic viability and friendly environment. In aspects of sustainability approach in our daily life, we should always prefer the best choice on any resources which are plenty of nature and renewable. Because, if we immediately don’t decrease our use of natural resources based on the earth’s crust (e.g. fossil fuel, gas, minerals etc), we could not be able to build the society sustained for our future generation. As we are being in the country of the tropical region, solar energy is unlimited and abundant resources to use it as a renewable source without the hassle of extraction from the earth’s crust- sustainability benefit 3 in context economic and environmental benefits. Physical degradation like loss or unproductive of land body, water body and biodiversity will not be encouraged if we continue to use our sunshine as the source of our energy in all the development sectors of Bangladesh in the context of achieving environmental sustainability. However, these are the overall major dimensions of achieving sustainability goals through the solar based irrigation system in Bangladesh.
As a part of sustainable agricultural development, the solar-run irrigation system has a high potential value in terms of previous sustainability benefits, but this new system has also some negative remarks that have been voiced in the project areas.
Firstly, the innovative irrigation system is using ground water resources extensively to irrigate the crop land. Different reports show that ground water quality is mostly better than the surface water (e.g. river, lake, pond etc) and good for crop health as well, but in context of sustainable manner, ground water resources are limited, even for our drinking and any production purpose. Because of extensive use of ground water in the irrigation system, the ground water aquifer is filling up its storage capacity by discharging saline water from the sea. As the long term impact, salinity intrusion has started to be channeled from southern part to the upper part of the country. Already this situation has been an alarming signal within the adverse impacts on agriculture in many areas of Bangladesh. The solution might be to use conjunctive sources of surface and groundwater, because the only use of surface water could not be possible in many areas as the sources of surface water are far away from the cultivable land, or not cost effective to collect, or because of polluted surface water reservoir.
Assuming the mixed sources of water use, our national policy should be carefully considered indicating the sustainability problems before selecting and elaborating the different options of conjunctive use of both water resources. Therefore, solar based irrigation needs to be planned with more feasibility studies conducted to determine the project area wise aquifer storage availability, and comparative environmental and economic benefits of the possible water sources.
Secondly, a recent report on the progress of solar based irrigation pumps shows that the present cost of irrigation is half of the previous cost of the diesel operated irrigation pump. In addition, solar pumps require fewer amounts of land and water in operating the irrigation technology. In the system, no drain is required to irrigate the land, so that the wastage of water is not headed so far. However, behind these entire positive remarks of the solar pumps, the project areas are getting also unpleasant experiences of a community whose livelihood particularly depend on diesel business. It is an evidence based experience that incorporating technology creates unemployment in some cases. In fact, diesel sellers are becoming very unhappy due to the revolution of new technology in the agriculture sector that runs without diesel. According to the report, diesel selling goes down less than one third compared to the situation before coming solar pumps in the project areas. Apparently, less selling, or less use of diesel is a manner of sustainable behavior in our daily life, but in another way, sustainable technology does not have rights to hamper anyone’s livelihood security. This is a confliction of sustainability interest in using the renewable technology; therefore, the solar irrigation system should be operated considering the recovery of all other socio-ecological impacts locally derived from the new technology.
Agriculture is still one of the highest priority sectors of the Bangladesh government, along with the energy sector. Also a priority of government concern is building the capacity to provide electrical power to ensure the food security for 160 million people now. In this context, the opportunity of solar power conversion into energy promotes the access of farmers to continuous energy supply which are significantly needed for agricultural drive.
In the process, we should innovate to overcome our growing burden on problems surrounding energy, water and food. Solar irrigation is one of such innovation to address the sustainability problems entire cycle of energy, water and food security for the next generations. Though it has a great concern to the technical and economic feasibility of solar irrigation systems, since the initial investment to implement this technology is quite impossible for the poor farmers.
However, a widespread of the technology depends on the financial and technical support to the farmers as much as possible. Finally, from the perspectives of sustainable irrigation technology, we need to continue our work on: further investigation of the feasibility of solar irrigation for site specific installation; evaluation of the recent development driven by solar irrigation; evaluation of energy conversion processes optimally; development of public-private partnership with a lot of new investment; and development of new entrepreneurship for the diesel business people driven by new technology adaptation in the project areas.
