[en] The present policy on energy development is geared towards harnessing renewable and indigenous energy resource which can offer clean, abundant and efficient power supply for the country. a review of the current generation mix of the power system, especially the Luzon grid will establish a high dependency in imported fuel - oil and coal to power our generating plants. Thus, the policy of reducing dependence on imported fuel will depend largely on the success of tapping the alternative renewable and indigenous sources. The sustainable development era of the 90's brought fresh interest on the performance and commercial viability of indigenous and/or renewable sources of energy such as wind, solar, geothermal, natural gas and water power or hydropower. Among these alternative renewable sources, water or hydropower is the most readily available, and will produce clean domestic source of electricity - no carbon dioxide, sulfur dioxide, nitrous oxide or any other air emissions. The potential is available in most parts of the country that are mountainous and have high rainfall. In terms of production, hydropower leads as the most developed and more proven in terms of commercial viability. It is also more reliable, efficient and less expensive than geothermal, biomass, wind and solar energy, as will be shown later. (author)

[en] A speciation analysis of Rare Earth elements (REE) in acidic waters of four natural systems in Brasil, Spain, Canada and USA is carried out. the geochemical diversity of the samples span a pH range of 3.3-5.2, a fairly broad range of SO₄=₄, F''- and PO''3- ₄ concentrations and a difference in measured REE concentrations of four orders of magnitude. The shale-normalized REE patterns shows a systematic, almost universal, IREE enrichment in all the acidic waters studied. From REE specification calculations using the PHREEQE code, it can be concluded that the dominant forms of REE are sulfate complexes (mainly LnSO''+₄) with minor free ionic species (Ln''3+). These free ionic species only became dominant when sulfate concentrations in waters are very low. Other ligands present in solution (PO''3-₄ and F''-) do not complete with sulfate in REE speciation in the concentration range spanned by the samples. At least two reasons can be put forward to explain this result: (i) PO''3-₄ concentrations are too low to affect REE speciation and (ii) F''- which is present in concentrations high enough to interface with lanthanide speciation, actually associates with aluminum. Aluminum, usually in high concentrations in acidic waters, is then the responsible of inhibiting REE fluoride complexation and hence, of inhibiting the important effect that this ligand has in REE speciation. Therefore, analytical determination of aluminium must be performed in order to properly calculate REE speciation in acidic waters. (Author) 29 refs