Alternative energy:

Is it an answer to the looming power crisis in Sri Lanka?

by Indeewara Thilakarathne

As the population grows, the demand for electricity is also increasing putting a strain on the economy. So far, the main source of power generation in Sri Lanka is hydroelectricity although fossil fuel is used to supplement the growing demand for electricity, especially during drought seasons.

The heavy cost incurred in producing electricity by fossil fuels and providing them to consumers at a reasonable price has caused losses on the part of the Ceylon Electricity Board (CEB) which produced electricity or purchase electricity from private organisations.

However, alternative sources of power have not been adequately explored in Sri Lanka though Sri Lanka is endowed with natural sources of power supply such as wind, solar power and waves. Another source of alternative power that Sri Lanka can harness is biofuel which can be produced from biomasses such as sugar cane.

Electricity generation is one of the most common sources of electricity generation is hydroelectricity which accounted for over 90 per cent of power generation in Sri Lanka.

However, other main sources of power generations are steam, wind, hot gases, solar and biofuel. Over the years diverse technologies have been developed for power generation.

In portable applications, solid state power generation is being used in the form of batteries and fuel cells. This area is largely dominated by thermoelectric (TE) devices, although other technologies such as thermionic (TI) and thermophotovoltaic (TPV) systems have been developed. Piezoelectric devices are used for power generation from mechanical strain, particularly in power harvesting. Betavoltaics is another type of solid-state power generator which produces electricity from radioactive decay.

Fluid-based magnetohydrodynamic (MHD) power generation has been researched into as a method for extracting electrical power from nuclear reactors and also from more conventional fuel combustion systems.

Electrochemical electricity generation is also important in portable and mobile applications. In most current applications, electrochemical power derived from closed electrochemical cells ("batteries") which are more popular as storage devices than power generating systems.

However, electromechanical systems such as fuel cell have been undergoing great deal of transformations turning them from being storages of electricity to systems that can be used to extract power either from natural fuels or from synthesized fuels (mainly electrolytic hydrogen).

In the Sri Lankan context, major alternative sources of power negation could be coal power generation which is relatively cost effective than diesel and other sources such as solar and wind.

These sources can either be used as supplementary sources to nourish the national grid or for rural electrification schemes where small housing unites or small scale industries outside the main grid can be powered. Given the risk and costly technologies associated with setting up nuclear power plants for power generation, unclear energy is still not an option for Sri Lanka.

Solar power as an alternative source, Solar cells, also referred to as photovoltaic cells, are devices or banks of devices that use the photovoltaic effect of semiconductors to generate electricity directly from sunlight.

However, the use of solar cells for mass power generation has been limited owing to its high manufacturing cost. One of the effective and common application of solar power has been in very low-power devices such as calculators with LCDs.

Another use has been in remote applications such as roadside emergency telephones, remote sensing, cathodic protection of pipe lines, and limited "off grid" home power applications and used in orbiting satellites and spacecrafts. Solar cells for cost effective uses are expanding against the back drop of declining manufacturing costs.

The average lowest retail cost of a large photovoltaic array declined from $7.50 to $4 per watt between 1990 and 2005.

In 2003, worldwide production of solar cells increased by 32%. Between 2000 and 2004, the increase in worldwide solar energy capacity was an annualized 60%. 2005 was expected to see large growth again, but shortages of refined silicon have been hampering production worldwide since the late 2004.

Instead of importing, Sri Lanka should explore the potential of large scale manufacturing solar panels for commercial and industrial use though solar power is used in a limited capacity.

Wind power

Using wind turbines, wind power is directly converted into electricity. Towards the end of the end of 2006, worldwide capacity of wind-powered generators was 74,223 megawatts though it is accounted less than 1 per cent of the world wide electricity use; approximately 20% of electricity use in Denmark, 9% in Spain, and 7% in Germany.

Between 2000 and 2006 wind power generation has been quadrupled. In windmills (a much older technology) wind energy is used to turn mechanical machinery to do physical work, like crushing grain or pumping water.

Wind power is used in large scale wind farms for national electrical grids and small individual turbines for providing electricity to rural residences or grid-isolated locations.

Wind energy is renewable and widely distributed and clean. It also reduces toxic atmospheric and greenhouse gas emissions if used to replace fossil-fuel-derived electricity. The intermittency of wind seldom creates problems when using wind power at low to moderate penetration levels.

In Sri Lanka, Hambantota and coastal areas in the Eastern province have been identified for setting up of wind power plants.

In order to attract large scale investor, mass scale production of electricity and providing of electricity at a reasonable price is a must and the authorities should also tried to minimize sudden black outs and strive to provide a continuous supply without fluctuating voltage, causing damage to household electronic equipment.

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