Harnessing solar energy to power NorthEast

[TamilNet, Sunday, 23 February 2003, 01:01 GMT]
Lives of thousands of poor households in the remote villages of NorthEast can be considerably enhanced if one can provide them with low-cost electricity to meet their modest lighting needs. The abundance of solar energy present in NorthEast and the availability of affordable photo-voltaic (PV) technology makes this possible. An examination of the feasibility of establishing a PV industry and its sustainability, its economic viability and the possible growth of the PV industry to branch into more challenging business endeavours, follows.

Solar cell
a 10cmX10cm 0.5V, 1W solar cell
Photovoltaic technology can have lasting long-term impact on providing economic and social benefits in NE. It is imperative that this awareness is raised among those who have the capacity to contribute to the development of the NorthEast and who have the frame of mind and financial strength to help ease the hardships of the poor.

Under World Bank procurement guidelines, $75m credit from International Development Association (IDA) and a grant of US$8 million from the Global Environment Facility (GEF) are financing the Renewable Energy for Rural Economic Development (RERED) Project. Solar Home Systems (SHS) are part of this arrangement, which also includes small-scale Hydro systems and biomass technology.

Microfinancing agreements and local distribution channels have been organized to support providing SHS systems to households under this program. The challenge, however, is to examine the market potential of the solar technology, its social benefits and the availability of inexpensive labor force to forge a business model that will provide long term benefits to the North East economy.

Establishing a business entity to provide photovoltaic systems to households can be the starting point. Configuring a business enterprise that can supply the required Solar Home Systems at significantly lower costs than those of existing systems is necessary for the effort to succeed.

Solar Cell Operation
Operational illustration of a PhotoVoltaic cell
The NorthEast effort can grow into supporting a range of applications such as powering street lights, computers and buildings and operating small scale grid structures that may eventually be used to export electricity when the national grid is brought closer to solar power centers.

PV cells are manufactured in different configurations and using different technologies. Of these, mono-crystalline versions which have a conversion efficiency of 10-15% (light to electricity) are commonly used for SHS systems.
  • Single-crystal silicon: Sliced from single-crystal boules of grown silicon, these wafers/cells are now cut as thin as 200 microns.
  • Multicrystalline silicon: Sliced from blocks of cast silicon, these wafers/cells are both less expensive to manufacture and less efficient than single-crystal silicon cells.
  • Gallium Arsenide (GaAs): A III-V semiconductor material from which high-efficiency photovoltaic cells are made, often used space power systems. Multijunction cells based on GaAs and related III-V alloys have exceeded 30-percent efficiency.
  • Thin-Film Materials: Provide low cost low efficient flexible PV cells. Amorphous Silicon (a-Si), Cadmium Telluride (CdTe) and Copper Indium Diselenide (CuInSe2, or CIS) are choice materials for thin-film solar cells.

Connection diagram
A typical 3-panel SHS showing key components and an AC load which will require the use of an inverter
Cells are interconnected, in series for voltages to be additive and parallel for the currents to be additive, to form panels. A 12V dc system capable of providing 30-45W of power is generally sufficient for a small scale SHS for use in the NorthEast. One requires 24-30 cells to produce about 15V output. This solar panel can be used with an appropriate charge controller to charge a 12V lead-acid battery with 12-20 AmpH rating (e.g., 2Amps for 6 to 10 hrs). The SHS is then sufficiently sized to power two 10W Compact Fluorescent Lamp (CFL) bulbs from 6pm to 12 pm.

A small SHS system would then have the following basic specifications:
  • A panel made up of 24-30 cells providing 15V nominal open circuit voltage with current output of 2Amps. i.e., providing approximately 30W of power. (~$100 excluding labor, quote from a New Delhi based manufacturer of solar cells)
  • Cell to Panel construction is labor intensive, and aconsiderable markup on price is imposed by the manufacturer. The NE-setup should endeavor to setup delivery channel for cells and implement the manufacturing process locally.
  • A charge controller, which costs between $25-45, can initially be bought. Assembling components locally to build low-cost systems needs to be investigated.
  • A 20AmpH lead-acid battery (~$50)
  • Two CFLs 10-15W each (~$20)
  • Wiring to support 12vDC circuits carrying 2 Amps

Usually measured in kwh/mxm/day (kilowatthour per sq.meter per day) the sunlight received by the NorthEast and other parts of SriLanka is a copious 5.6 units (worst case year round average), one of the highest among nations as seen in the insolation map. Sunlight falling on the face of the earth ranges from 200 to 1000Wp per square meter. The solar power received on a cloudless summer day on surface directed towards the sun in the NorthEast it is closer to 800Wp per square meter.

Insolation Map
Insolation map of Asian countries (Click for a larger Map)
According to the World Bank's project report, "SHS are least cost alternatives for areas with dispersed populations and where grid extensions are expensive. Even in other areas the costs of SHS compares favorably with those of grid expansion. The solar component under this project would provide electricity to nearly 85000 households at a capital cost of $28m ($330 per household). Extending the grid to the rural areas in SriLanka would cost about $350 per connection, not counting the cost of generation investment which is at least $500 per KW." The report also cautions against comparison, pointing out that grid provides other service possibilities that are not available in PV systems.

The World Bank's report estimates the cost of 40Wp SHS system to be $452. Cost analysis done by TamilNet reveals that SHS systems can be made much cheaper if local labor is used for manufacturing panels and possibly building the low complexity charge controller.

Investment in a solar-energy based PV industry at an early stage is imperative for the future well-being of NorthEast. The following factors related to the future need for power in Sri Lanka and the growth possibilites of a local industry confirm this need.

Local PV Industry's growth potential:
  • Initial setup to ensure feasibility by powering about 25 homes using locally manufactured parts and establishing the cell procurement channels. Practical drawbacks of installation, manufacturing defects, impact of weather to be identified and solved during this early phase.
  • Establish funding channels and provide SHS systems to needed households in the NorthEast, an estimated 200,000 to 500,000 homes. Obtain required expatriate funding to assist needy households and organize easy payback schemes.
  • Use appropriate technology and strict manufacturing standards to expand distribution channels to whole of Sri Lanka, a potential of one million additional SHS market. Explore potential as an exporter to South Asian markets.
    Solar panel
    Solar panels and associated components
  • Expand manufacturing operation to produce PV systems to cater to higher end-users of 100W to 500W systems. This would enable appliances like refrigerator, television, etc. to be powered. At this stage, transitioning to an AC delivery arrangement needs to be considered.
  • Expansion of solar energy supply to specialized narrow markets, such as street lights, remotely operated water pumps and associated setting manufacturing operations to produce different sized panels, controllers and battery systems.
  • Construction of specialized solar farms to provide community based medium scale energy distribution to local communities. This would setup an infrastructural framework to export electric energy to grid when it becomes available.
  • As the culmination of this development, it may become feasible to consider a local PV-cell manufacturing plant. Investment in the order of $5m is necessary as a basic need for a 5MW/year manufacturing capacity.

The possibilities of developing a PV-industrial setup becomes more pertinent when one considers the use of increasingly high-cost thermal energy to satisfy rising energy requirements.

Current and Projected Energy Needs:
  • Taking into account of nearly 1 million households in the NorthEast, a total close to 2 million households in Sri Lanka will not receive electricity from the grid till 2007.
  • Sri Lanka has no fossil fuel reserves and therefore is domestically dependent on fuel wood and hydro-power. The current installed capacity of 1,779 MW, of which the CEB (Ceylon Electricity Board) owns a total of 1,593 MW, comprises 1,137 MW of hydropower, 453 MW of thermal power and 3 MW of wind power. The private sector owns 186 MW of thermal power.
  • The demand for electricity in Sri Lanka has been growing at an average annual rate of 8%. Dependence on costly thermal power was increased from 21% in 1990 to 35% in 2000.
  • Power generation will need to be increased from 6,800 GWh in 2000 to about 15,000 GWh in 2013. The share of hydropower is expected to decrease to 32%. The balance will be met by thermal power generation.
  • All transmission is controlled by the CEB, and it distributes 85% of the power produced. The balance is distributed by the Lanka Electricity Company (LECO). In 1984 the Government, the CEB, local authorities and the Urban Development Authority jointly set up LECO. Grid expansion will be limited as it is capital intensive.
  • Although presently small, private sector participation in the power sector (Independent Power Producers - IPP) will continue to expand. Details of recent IPP projects are as follows:
    • Lakdhanavi (Pvt) Ltd has a 22.5 MW diesel power plant at Sapugaskanda.
    • Asia Power (Pvt) Ltd (an international consortium which includes KHD of the UK and the Commonwealth Development Corporation), situated at Sapugaskanda and has a capacity of 51 MW. Developers have submitted plans to extend this plant by a further 51 MW.
    • 60 MW barge mounted power plant, constructed in Japan and moored at the Colombo Port on a BOO basis was commissioned in June 2000.
    • An 8 MW diesel power plant by Kool Air (Pvt) Ltd in Kankasanturai was established in 2000.
    • Construction is underway for the American Energy Services (AES) 163 MW combined cycle power plant at Kelanitissa. This is to be commissioned in two stages, the first in mid 2002 and the second in mid 2003.
    • The initial work has been completed to construct two diesel power plants of 20 MW by a consortium of investors led by Ace Power Ltd, a local company (investors include Wartsila NSD Power Development of Finland and Commonwealth Development Corporation).
  • CEB's average cost of electricity generation has gradually increased from Rs 2.11 per unit in 1991 to Rs 6.31 per unit in 2000, mainly due to increasing reliance on thermal power, increased fuel prices and the cost of power from private suppliers. At present, Sri Lanka's average electricity price applicable to the industrial sector (US cents 7.4 per KWh) is considerably higher than that of most other Asian countries, e.g., Indonesia US cents 3.0 and Singapore US cents 5.8 (source: Central Bank of Sri Lanka Annual Report for 2000). This situation has led the authorities to consider building a coal-powered station.
Application of other forms of renewable energy sources such as windmill, geo-thermal energy, bio-mass, wave energy and sawdust can also help to decentralize electricity generation to meet electricity needs of rural and remote areas also needs investigation.

There is an urgent need for a concerted initiative to build the solar industry in the NorthEast if the people and the economy of this region are to benefit from the abundance of solar energy, a natural wealth, which we are fortunate to be endowed with.

External Links:
  1. How Solar Cells work
  2. Worldbank's Renewable Energy Project Pages
  3. Power Profile for Sri Lanka
  4. U.S National Renewable Energy Laboratory (NREL) Pages


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