Renewable energy or not?
Most of the people might outrightly conclude that any geothermal energy sources, like what PNOC-EDC and Chevron Geothermal and Power owned and operated in the Philippines, is renewable because of what it seems infinitely abundant source - the heat of the Earth. But experiences showed that it is not always the case, besides, the steam supply decline because of the decrease of temperature and pressure of the geothermal reservoir is the common problem of many Geothermal Plants in the Philippines. Tiwi in Albay, and MakBan in Laguna are the example of those plants with steam decline problem. >>More of these on http://www.jcmiras.net/jcm/item/95/
Status of Geothermal Energy production in the Philippines
There are only who companies that are involved in the development and operation of geothermal energy resources in the philippines - Chevron Geothermal and Power which supplies the steam requirement of Tiwi and Makban Power plants in Albay, and in Laguna, and PNOC-EDC which operates the steam field in Bacon-Manito in Albay, Leyte, Northern and Southern Negros, and Mount Apo. Philippines is the second largest supplier of geothermal energy, second only to the United States.
Though the total installed capacity of geothermal power plants in the Philippines is around 12.5% based on the 2006 DOE data, its contribution to the total electricity generated is around 18.42%. However, due to the advent of the Wholesale Electricity Market in June 2006, which in somehow gives a priority dispatch to contracted plants of the distribution utilities rather than to the cheapest plants like geothermal plants, we are expecting that its contribution to the countries supply of electricity in 2007 will be lower than what it should be. This dilemma can be seen on Tiwi and Makban Plant where steam supply is just bented-off to the atmosphere (around 50%, I think) during low demand periods thereby loosing precious energy. It is very important to know that geothermal energy is like electricity itself - once it started generating, we cannot store it, and that if there is no demand, it has to be thrown away like waste. In short, a wasted energy.
Aside from the inefficiencies in the energy market, the degradation of NPC-owned and operated geothermal power plants due to budget-constrained poor maintenance also reduces the dependable capacity of these plants. Also, the slow progress of repairing damaged transmission line in Bicol area, and the limited capacity of the Leyte - Cebu line restricts a higher utilization of geothermal plants in Bicol and Leyte, respectively.