Geothermal handbook: PlanninG and Financing power Generation t e c h n I c a L r e p o r t 2 / 2

Small geothermal Systems
The special case of small distributed geothermal power generation refers to the experience of rural 
power development in Latin America, the Caribbean, and the Philippines, among others.
The decision in favor of distributed geothermal generation may be made due either to scattered 
resource availability or fragmented demand centers. 
Small geothermal power projects (0.5 to 5 MW per installation) could be an attractive solution for island 
states with limited demand, since geothermal provides reliable base-load power. For the peak demand 
within a given power system, geothermal energy can be successfully combined with other renewable 
energies like solar, wind, and hydropower, or most fossil fuel technologies. Geothermal can improve 
living conditions on remote islands by providing cheaper domestic energy while reducing dependency 
on fossil fuels.
An exploration plan for small geothermal plant sites should pool exploration risks across many small 
projects and identify a group of projects that will be logistically viable when bundled. Small projects 
cannot afford high drilling costs on the order of millions of dollars per well, which are typical for large 
projects. Drilling slim holes for exploration and production or using smaller, more portable drill rigs are 
promising methods to reduce costs in such locations (Vimmerstedt 1998).
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Under the World Bank supported Leyte-Luzon Geothermal Project, as a result of declining capacity of the production wells of the 
Mahanagdong field (primarily due to clogging), the output of the 120-MW plant declined to 72 MW. PNOC-EDC managed to increase the 
output through scale drillout (cleaning of wells), acidizing, drilling of additional wells and deposition inhibition techniques and the plant has 
been operated above 100 MW. In order to avoid similar problems in the future, it was decided to build a steamline interconnection system from 
Mahanagdong to other fields where surplus steam was available (World Bank 2000). 

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G e o t h e r m a l H a n d b o o k : P l a n n i n g a n d F i n a n c i n g P o w e r G e n e r a t i o n 
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