Feasibility of solar pump for sustainable irrigation in Bangladesh

M. A. Hossain 0 M. S. Hassan 0 M. A. Mottalib 0 M. Hossain 0 0 M. A. Hossain (&) M. S. Hassan M. A. Mottalib M. Hossain Farm Machinery and Postharvest Process Engineering Division, Bangladesh Agricultural Research Institute , Gazipur 1701 , Bangladesh A base-line survey was conducted in 2010 at different locations of Bangladesh to know the present status of solar pumps. The respondents were solar pump users, suppliers and service providers. There were about 150 solar pumps in Bangladesh, among them 65 % were used for supplying drinking water to the poor people of the locality and about 35 % solar pumps were used for irrigation purposes. The size of solar pumps varied from 300 to 1,190 Wp and discharge capacity varied from 2,000 to 800,000 L/day. Panel cost was the major cost (45 %) in solar pump followed by the costs of installation (18 %), motor (16 %), pump (10 %), and pipes and fittings (4 %). Life cycle cost of diesel engine-operated pump was lower up to 5 years. After 5 years, the life cycle cost of solar pump became lower than that of diesel engine-operated pump. Benefit cost ratio, net present value and internal rate of return of solar pump were found higher than diesel-operated pump. Therefore, solar pump is profitable and investment on solar pump is more risk free than diesel engine-operated pump. Diesel engine-operated irrigation pump emits carbon dioxide and pollutes environment, but solar pump is an environment-friendly irrigation technology. - There are about 1.71 million irrigation pumps in Bangladesh among them 83 % are diesel engine-operated and 17 % are electricity operated [1]. Solar pump may be an alternative for small-scale irrigation for crop production in the off-grid areas of Bangladesh. Solar pump is a pollutionfree and environment-friendly water pumping system in agriculture. Being a tropical country, Bangladesh is endowed with abundant supply of solar energy. The ranges of solar radiation are between 4.0 and 6.5 kWh/m2/day and the bright sunshine hours vary from 6 to 9 h/day [2, 3]. In Bangladesh about 60 % land is under irrigation. There is a vast area to be irrigated where most of the areas (Charland, coastal area, hilly area, etc.,) have no grid connection. Solar PV pump may be used for irrigating these lands to enhance crop production and to increase cropping intensity. Abu-Aligah [4] reported that in locations where electricity is not available photovoltaic pumping system is a good option for irrigating crops and supplying drinking water. Advantages of PV pumping systems include low operating cost, unattended operation, low maintenance, easy installation, and long life. These are all important in remote locations where electricity is unavailable. Namibia renewable energy programme (NAMREP) conducted a study on feasibility of solar pump in Namibia [5]. The report furnished that for small- to medium-sized wells, solar photovoltaic pump was much cheaper on a life cycle cost basis than diesel-powered pumps. When looking beyond the original purchase price, solar pumping systems costed from 2256 % of diesel pumps cost and can achieve a payback over diesel engine-operated pump little as 2 years. It is also reported that maintenance and high fuel costs have been long-standing problems with diesel engine. The systems were often in remote locations, and the difficulties of purchasing imported spare parts and fuel have often made them unreliable. Hahn [6] reported that in regions with high insolation levels, photovoltaic pumping systems were technically suitable for use, beneficial for the environment and were able to yield cost advantages over diesel engine driven pumps. However, the high initial investment costs were still the main obstacle for acceptance of solar pump. He added that fuel and lubricants for diesel pumps often pollute wells, soil and groundwater. By contrast, photovoltaic pumps are an environmentally sound and resource conserving technology. Contamination of soil and groundwater resources could be completely avoided when using solar pump. Burney et al. [7] conducted a study in the rural Sudano Sahel region of West Africa. Using a matched-pair comparison of villages in northern Benin, and household survey and field-level data they reported that solar-powered drip irrigation significantly augmented both household income and nutritional intake, particularly during the dry season. Group for rural infrastructure development Nepal (GRID Nepal) initiated PV water pumping project at Bhujikot provided by Nepal development marketplace for supplying drinking and agriculture water to the rural people. The feedback from the community people was very encouraging and they were very happy with the successful work. Solar pump provided their fresh drinking water and increased agricultural production thus improving and upgrading the life style of the community people [8]. Zieroth [9] conducted a feasibility study on water supply by solar pump in Mauke, Cook Island. The solar project showed a good performance in comparison with dieselpowered pump. Cost of solar pump use was US$ 0.16 per m3 as compared to US$ 0.22 per m3 for the diesel-powered pump. At the discount rate of 10 % the net benefits of solar savings were equal to an economic rate of return of 31.5 %, i.e., the solar project was quite economic. In 1999 and 2000, cabbage and peppers, respectively, were grown comparing solar and conventionally powered drip irrigation systems at the Rutgers University Research and Extension Farm, Pittstown. The solar system was operated by a 1.5 horse power (hp) motor powered by 18 solar modules. Utilizing the suns energy, captured by photovoltaic panels, to power irrigation systems offered a costeffective, pollution-free and virtually maintenance-free alternative to diesel pumps in remote areas. Solar-powered pumping systems were capable of delivering water from rivers and wells in volumes up to 2,000 gallons/min [10]. Odeh et al. [11] made a comparison of the economic analysis of photovoltaic and diesel water pumping systems of sizes in the range 2.815 kWp. Net present value, annuity and cost annuity per equivalent hydraulic energy unit were calculated. It is found that PV water pumping systems are more economical than diesel pumping systems for equivalent hydraulic energy below 2,100,000 m4/year, where diesel pumping systems become more economical than PV water pumping systems for larger applications. Curtis [12] conducted an economic feasibility study of solar photovoltaic irrigation for forage production in the Great Basin Nevada, western Utah. He reported that solar PV irrigation system was a cost-effective alternative for forage production the area. Production cost of the alfalfa stand, decreased annual operating costs, but increased annual ownership costs. Annual farm net returns to production also increased from $1,395.17 to $5,449.10, or $10.90 per acre. A PV solar pump was also tested for irrigation in Bangladesh Agricultural Research Institu (...truncated)