Introduction To Renewable Energy

Renewable energy is energy that tapped from the continually replenished sources, typically solar, biomass, wind, tidal, and hydro. The potential of large hydropower in Sarawak is largely known with several studies undertaken by government bodies, consulting firms and utility companies. However the potential of small renewable sources comprising of solar, biomass, wind, tidal and small hydro is largely unknown and hence, these resources are largely untapped.

Recognising the importance of utilising these small renewable energy sources in the State, the Government of Sarawak incepted the Small Renewable Energy Master Plan in early 2009, which encompasses a spectrum of major comprehensive study to determine the theoretical and economic potential of these small renewable sources in Sarawak. This study conducted in the year 2009 to 2010, will then facilitate the mapping of these resources and open the door to explore and identify their potential applications for fully utilisation in urban and rural development. The master plan is overseen by a steering committee comprising of representatives from Sarawak Energy Berhad (SEB), relevant government agencies of Ministry of Public Utilities, Ministry of Rural Development, Public Works Department, and education institution of Universiti Malaysia Sarawak (UNIMAS).

The solar on-site survey has been carried out in several sites in Sarawak currently. These sites were installed with the weather sensors for measuring the sun irradiance. The recorded data is used to calibrate the simulation model or the satellite image data in order to increase the accuracy of the solar mapping in Sarawak.

Biomass is a collective term for all plant and animal material. A number of different forms of biomass can be burned or digested to produce energy. In Sarawak, the agriculture sector remains as a major economy activities. Agriculture waste such as palm oil biomass is still not optimally utilised, even though theoretically there is a potential of 375 Megawatts (MW) of renewable energy from biomass and biogas based on current production rate of oil palm in the State. There are many more agriculture biomass source options in Sarawak including cocoa husk and sago wastewater, but the extent of production is not yet promising for power generation due to the cost factor and the status of biological engineering in strain research makes algae cultivation for bio-fuel not possible at this instant. Another opportunity for biomass power generation in Sarawak is the landfill gas and sewerage. However, the energy conversion processes are crucial in utilising the biomass and biogas efficiently.

Acknowledging that the biomass also has other potential use which is yet fully developed, it is of the opinions and the best interest of all aspects that the biomass produced from the agriculture sector shall be best utilised. The policies and regulations including the establishment of standards that directs to the efficient utilisation of agriculture waste and environment conservation as well as reasonable incentives for the plants and more attractive electricity price are necessary to encourage the biomass utilisation.

The wind resource identified in the Sarawak wind resource map through the weather sensor installed in several sites can generally be characterised as low wind resource, which is typical of many regions at this latitude. Areas located at higher elevation and along the eastern side of Sarawak display the highest wind resources. However, higher elevation and temperature can have an effect on the air density, which in turn affects the power that can be extracted from the wind. A reduction in air density lowers the energy output from a wind turbine. Sarawak contains areas with elevations from sea level up to 1600 m near the Bario region in the eastern mountainous area.

Tidal power is the generation of electricity through extracting energy from the ebb and flow of tides. The sustainability and predictability of the energy is sensible for tidal energy harnessing. In addition, it is a good option for utilising the tidal energy for the in-situ activities at the vicinity of coastline with the merit of minimum transmission losses.

The tidal study has examined the potential of tidal stream energy extraction for eight different sites at multiple angles. The speed of the tidal stream at Muara Batang Lupar meets the 1.5m/s minimum requirement used to justify if further investigation against the potential of generating power by extracting tidal stream energy.

The result from tidal study shows a relative consistency of the speed of tidal stream at the North West region of areas offshore of Sarawak, stronger than those found at the North East region (Bintulu and Miri). Hence, the continuing study of sites with potentially high tidal stream energy should be concentrated off the coast of the Southern (Kuching) region and Middle (Sibu/Mukah) region of Sarawak. Although none of the locations in the study shows good potential for tidal stream extraction, the advancement and evolution of technologies is making its way for extracting energy from slow moving tidal streams.

Under the study of micro-hydro potential in Sarawak, there are over 100 sites in the State have been surveyed. The focus is on rural villages that are currently not connected to the State Grid or to any of the local suburban power networks. The survey is correlated to the projected power demand of the nearby villages. The survey and mapping classified the power potentials into two categories which are the low head/low power potential and the high head/high power potential. The survey shows that the greatest concentrations of micro hydro potentials available are in Kapit and Limbang Division with vast networks of streams and tributaries on the rugged and mountainous geographical topography. Some of these sites do show sufficient capacity to fulfil the demands of the local population. Hence, a more comprehensive study shall follow to assess the reliability and sustainability of the water resources at these sites for power generation.

The results from the studies of small renewable energy potentials indicate that biomass and biogas from palm oil mills have the greatest potential for grid power generation. Micro-hydro facilities are suited mostly for small-scale rural supply. Sarawak has considerable solar potential but solar is currently not competitive for utility scale grid generation. Nevertheless, the prospective for solar Photo-Voltaic (PV) applications in the remote rural areas may lie on long term viability. Sarawak also does not possess significant potential of wind power generation. The tidal potential also appears to be limited at this stage of study and it is of the opinions that a more comprehensive and systematic search for potential tidal stream energy shall be carried out in future.