In 2000, National Renewable Energy Laboratory (NREL) completed a national assessment of solar resources of the Philippines. This assessment combines existing ground measurement data collected in the Philippines and the output of NREL’s Climatological Solar Radiation (CSR) Model. This model converts information on satellite- and surface derived cloud cover data collected at a 40-km spatial resolution to estimates of the monthly average daily total global horizontal solar resource. This spatial resolution is generally much higher than the spacing of ground stations, and therefore allows for a more detailed analysis of the effects of microclimate variability on the solar resource, and provides a more accurate interpolation of the solar resource between ground stations.
An annual and twelve monthly average daily total global horizontal solar resources data were generated. Each of which shows the comparison of the data grid value with the corresponding surface value for Science Garden and Victorias Milling Corporation. The study shows that because the Philippines climate is characterized as monsoonal, solar resources vary between the dry season (November – May) and the wet season (May - October).
In addition, the geographical location of San Carlos City, being in the eastern coast of Negros, and the presence of mountain ranges in the center of the island makes it drier and exposed to more sunshine compare to the western and northern part of the island. These mountain ranges block the cumulus clouds that bring water during rainy months.
Negros Island is considered to be one of the best locations for a solar farm. An NREL study shows that an average of 5.0-5.5 kwh/m2/day of power can be generated. The months of February to October was recorded as the time were solar energy is as its peak as shown on the map below.
This assessment provides data to developers and investors to help establish successful business in solar technology in the Philippines.