Energy Development Corporation (EDC)is the largest producer of geothermal energy in the Philippines and the second largest in the world. Being a leader and pioneer in renewable energy industry, EDC continues to grow and adapt applicable technologies as reckoned useful to the company’s energy resource development and management objectives. One of the technologies is remote sensing.
There has been an increased globalattention to climate change, environmental protection, and sustainable development in the past years. This in turnaugmented interest in renewable energy sources and less dependence onfossil fuels.The Philippines is in tune to all of these global developments, especially in the field of renewable geothermal energy, starting geothermal resource exploration as early as 1964 and pilot plantdevelopment in 1967.
In the course of characterizing commercially productive geothermal systems, extensive and costly resource exploration and management strategies are needed. Hence in order to reduce risks and outlay in developing sustainable geothermal energy production fields, strategic exploration and management technologies are used and one of these is remote sensing.
EDC and its role in developing renewable energy sources in the Philippines
Established in 1976, Energy Development Corporation or EDC is a pioneer in geothermal steam field development in the Philippines. Its main mandate is to tap onto indigenous sources of power to make the country less dependent on foreign oil. In addition to developing steam fields, the company also went into power generation in 1996 through the Build-Operate-Transfer scheme stipulated in RA 6957.
Figure 1: Fuel input mix for power generation in the Philippines in 2010 and 2011.
As can be seen in Figure 1 above, geothermal energy constitutes at least 41% of the total fuel input mix for power generation in the Philippines. It is estimated that EDC contributes at least 60% of that geothermal energy input. Recognizing the fact that steady power supply, decreased consumption of foreign fuel, and energy self-sufficiency are critical indicators ofPhilippine economic development and that the government continues to push for the development and use of indigenous renewable energy sources, we can clearly seethat EDC plays an important role in the country’s economic, energy, and environmental sectors.
Importance of remote sensing in geothermal energy exploration and management
The EDC Experience
In the tradition of being at the forefront of geothermal-related research, EDC has alreadyconducted several studies and research about the applicability of remote sensing to various geothermal resource exploration and management activities. For example, EDC has used spectral classification (i.e. through the use of Normalized Difference Vegetation Index or NDVI and Principal Component Analysis or PCA) of Landsat TM and Synthetic Aperture Radar (SAR) imageries at Southern Leyte in order to refine existing hydrothermal and geologic models of the study area. EDC has also used airborne, topographic, and polarimetric SAR (AIRSAR, TOPSAR, and POLSAR respectively) in generating digital elevation and general surface geology models for a study area located at Northern Negros.
However, due to manpower movement, prohibitive costs, and lack of prioritisation, it is only recently that EDC again began to put attention to remote sensing applications. This is manifested by a recent work done at Tongonan, Leyte wherein Differential Interferometry SAR (DInSAR) was used to map out ground movement within the study area, the considerable increase in the number of acquired satellite data, and some efforts being made to generate thermal maps at the Leyte Geothermal Production Field (LGPF). Comparative analyses of Digital Elevations Models (DEM) derived from remote sensing data of various EDC geothermal production fields were also recently done in order to quantitatively assess the consistency of the datasets and to check suitability for actual utilisation. Structural mapping of fault lines and other geologic features using SAR data are also now being initiated by the company.
Figure 2: Graph showing the number of acquired remote sensing data by EDC per year. Notice the acquisition gap between year 2000 and 2009.
Current Uses, Limitations, Challenges, and Opportunities
The table below summarizes the current uses of various remote sensing data in EDC. It also enumerates the limitations, challenges, and opportunities that the company is facing.
Examples of 2D and 3D visualization and analysis include generation of hill shades, area measurements, profiling, and volume computations. Hydrology applications include generation of watershedsand waterways directly from the DEMs. Structural mapping is the process of delineating fault lines from the DEMs and DSMs. Thermal mapping on the other hand makes use of the Thermal Infrared band of the Landsat images to compute for Land Surface Temperature (LST) at areas of interest. Feature extraction pertains to digitizing visible natural and man-made featureslike rivers, roads, geothermal pipelines, and built-up facilities.
Future Activities
Given the fact that the demand for electricity in the Philippines will continue to increase (Fig. 3), that the world clamours for sustainable development through the use of clean and renewable sources of energy, and that the Philippines is aiming to further increase its green energy output (Fig. 4), it is expected that EDC will continue to grow and expand as one of the world’s premier renewable energy company.
Also, given the proposed evolution of exploration technologies in geothermal resource exploration and management, wherein we see an increased role of remote sensing due to the thrust of the geothermal community to make exploration activities more cost effective and strategic, it is expected that EDC will also increase its use of remote sensing technologies by increasing its knowledge base and by acquiring more remotely sensed datasets.
Possible near future activities include the following:
- LiDAR remote sensing for topographic mapping, corridor mapping, and other geoscientific and engineering applications;
- Improved thermal remote sensing by integrating biophysical and agro-meteorological parameters;
- Increase use of SARdata in geodynamics/geomorphology studies;
- Introduce use of satellite gravimmetry for geodetic applications; and
- More efficient use of existing data by developing more advanced remote sensing techniques suitable for geothermal resource exploration and management.
Figure 3: Power supply and demand outlook in the Philippines from 2012 until 2030. The figure shows that the country needs to produce more energy in order to meet the demand in the very near future.
Figure 4: Targeted energy output by 2030 from various renewable sources in the Philippines by the Department of Energy.
Conclusions
As the world continues to be environmentally conscious and demand for green sources of energy, EDC will continue to explore new sources of clean and renewable energy sources and will continue to maintainefficient management of its existing geothermal production fields.
Also, with the current thrust of the international geothermal community to make its resource exploration and management much more cost effective and efficient, it is foreseen that the use of remote sensing in geothermal-related applications will continue to increase and mature. It is expected that EDC will catch on with these foreseen advancements as the company continues to be the premier indigenous, clean, and renewable energy developer in the country.
