Bangladesh has been enviously progressing towards beneficial use of solar home systems for supplying electric energy to the consumers who are not under grid coverage.
Bangladesh targets 10% electricity generation from renewable sources within 2021. For attaining this target various fiscal and policy support initiatives have been offered in the country.
In 2003 the target was put forward by the government to install 50,000 solar home systems (SHS) within 5 years but the target was attained within 3 years.
Since 2003, nearly four million Solar Home Systems (SHS) has been installed in Bangladesh and the government targets to attain six million SHS installation within 2017.
Electric energy generated from SHS not only is used for lighting the house, shops, boats, small and cottage industries but people use the energy for charging mobile phones, watching television and for other purposes.
The already installed SHS generate a total of 145 MW which supplements a significant part of the country`s present power generation.
Infrastructure Development Company Limited (IDCOL), the non bank financial institution created by the government has been assisting to finance the renewable energy projects including SHS project in Bangladesh.
The next big thing the IDCOL has undertaken is to finance and focus to promote the installation of solar irrigation pumps in Bangladesh. In addition, the Power Division has created `Sustainable and Renewable Energy Development Authority’ (SREDA).
SREDA focuses on installation of 500,000 solar power pumps across the country within 2020. More than 200 solar powered irrigation pumps have been installed in the agricultural fields in Bangladesh. The objective SREDA intends to attain by promoting solar irrigation pumps is to gradually replacing the already installed 1.3 million diesel run `shallow tube wells` currently being used for irrigation purposes.
As per available information, there are approximately 1.7 million irrigation pumps (100%) including 17% electric energy driven deep tube wells in Bangladesh. During peak irrigation season, an estimated 1,500 MW electric energy and 0.9 million tonne diesel require for operating the deep and shallow tube wells in Bangladesh.
The solar energy in aid to the conventional energy can help operating the irrigation pumps and reduce the use of grid power and imported diesel fuel. Use of increased numbers of solar irrigation pumps will help reduce the fossil fuel use and carbon emission in the atmosphere. At the same time, improved solar panels facilitates now directly converting the solar energy endlessly radiated in the agricultural fields to convert in electric power to run the irrigation pumps.
No battery is now required for storing the electric power to operate the irrigation pumps. This technological advancement reduces costs and making the solar energy driven irrigation pumps environment friendly.
As in other parts of the country, there are 3 installed solar irrigation pumps in the Tegharia village under Poradaha Upazila of Kushtia district. These three solar irrigation pumps have been installed in July 2015 by the local NGO Bright Green Energy Foundation with financial assistance from IDCOL in the middle of agricultural fields and they have been operating without any noise and without any break from dawn to dusk.
Each solar irrigation pump consumes 13 kW energy and has a 125 bigha (33 decimal = a bigha ) command area for irrigation and the pump extracts from 240-250 ft deep underground approximately 180,000 liters of water daily. The farmers have been getting water for their paddy and banana fields without any trouble.
Approximately 10 decimal of land was required for installing the solar panels, pumps and their water distribution systems for the command areas. Almost there is no operation cost involved for running a solar irrigation pump daily.
But the cost involved for installation of a solar pump in the Tegharia village was approximately 4.5 million Taka. Depending on the capacity of the pump the irrigation command area may vary.
The organization that has to install a solar pump may get financial help from IDCOL in favorable terms. But the rate for supplying water to the farmers needs to be negotiated between the beneficiary and suppliers.
It is expected that the irrigation water supply cost using a solar pump may remain less that the costs of irrigation water supplied by the diesel operated shallow pumps. The initial high cost for solar irrigation pump installation appears as a barrier for its rapid expansion and increased use.
The government agencies in cooperation with international banks and financing institutes have been encouraging the initiatives by providing grants and low interest credit supports. At this stage IDCOL is providing financial supports on a debt, equity and grant ratio of 30:20:50 to help accelerate the number of solar irrigation pump installations in the country. At the same time providing electricity connections from grid lines to irrigation pumps are discouraged.
Both government and non-government organizations have been involved in installation and popularizing the solar irrigation pumps in the country.
The SREDA officials are hopeful that the target for replacing the major parts of the diesel driven irrigation pumps will be attained within the targeted timeline. By encouraging solar irrigation pumps through institutional loans and organizational efforts the new agriculture technology and new capital and knowledge are expected to reach the rural Bangladesh at a faster rate.
As a result the agriculture will find further encouragements for diversity and can contribute more for the national development.
The primary barriers for making the solar irrigation pumps have been successfully overcome and the relevant officials involved in the business consider that the initial slow pace will shortly be changed. And several thousand solar irrigation pumps will start irrigating the agriculture fields in the country.
But the new issue starts surfacing with the solar pump operations. The agriculture fields require artificial irrigation mainly for the dry seasons, especially for the Boro paddy cultivation.
During the other months of the year when irrigation intensive agriculture crop does not require irrigation water. The solar panels installed for the irrigation pumps are able and can continue to generate electricity provided the panels are connected to supply the produced electric power to consumers.
At this moment such facilities to supply electricity from the solar irrigation pump facilities are absent. This situation compels the installed solar panels to be less effective technically and less cost competitive in financial terms.
The technical challenge remains open for connecting the individual solar irrigation pumps to power supply grid or to specific consumers like rice husking mills, small and cottage industries etc.
Now the financial challenge is to work out modalities to sell the generated electricity and its tariff rate. Also, it is to be worked out who will develop the necessary power lines and other infrastructure for the scattered solar irrigation pumps.
If these issues can be addressed successfully, the solar irrigation pumps will help change the rural economy and can contribute significantly to supplement the energy supply in the country.
Dr. Mushfiqur Rahman is a mining engineer, and writes on energy and environment issues.