Due to the exhaustion of fossil fuel resource, to develop renewable energy is the unavoidable choice in the globe, and is the direction of energy development in our country. But the stochastic nature and intermittent character of renewable energy as wind or solar energy will finally lead to a significant impact to the balance of electric grid and the stability of grid’s frequency, if the development rate of renewable energy keeps growing. It had better do something necessary to prevent this situation. One good manner is to build up electricity energy storage facilities to make up the grid’s variety and electricity discrepancy. There are many kinds of storage facilities to meet different conditions. Among these, Pumped hydroelectric storage (PHS) has proved itself as the most reliable kind and fits the real need for grid’s management. Our country’s grid will have a structural change in the near future, it is suitable to increase the PHS capacity to stabilize the grid’s system. But PHS means a huge investment, the digital terrain model (DTM) is used for the investigation and preliminary study to select the potential sites to develop PHS. This project sets the goal to search the sites of conventional PHS type in Taiwan Island, to search he sites of seashore PHS type in Quemoy and Matsu Islands, and to search he sites of seawater PHS type in eastern coastal of Taiwan Island. The threshold for conventional PHS type is set 300MW Installed capacity. For there are more than 1 suitable site at the same region, and the Project is seeking the development priority list for sites in the same region. The selection factors for deciding priority are (1)benefit/cost ratio or unit construction cost, (2)impact to environment or ecological system,(3)construction or technical challenge, (4)magnitude of installed capacity. The preliminary result in this Project is listed in different region as below: In the Northern region in Taiwan Island, the suggested sites are listed as the following: (1)Site Nanao in Ilan County,(2)Site Feitsui Reservoir in New Taipei City,(3)Site Shimen Reservoir in Taoyuan County,(4)Dananao PHS Project,(5)Site Hoping in Hualien County. Where Site Nanao and Hoping are of seawater PHS type. In the Central region in Taiwan Island, the suggested sites are listed as the following: (1)Kuangming PHS Project, (2)Hsihuang PHS Project site. In the Northern region in Taiwan Island, the suggested sites are listed as the following: (1)Site Mudan Reservoir, (2)Site Nanhua Reservoir, (3)Site Tzengwen Reservoir. In Quemoy Islands, Site K2 and Site K3 are planned and coupled with wind generating units. In Matsu Islands, Site M1 and Site M2 are planned and coupled with wind generating units.

electricity energy storage;pumped hydroelectric storage;installed capacity;conventional pumped storage type;seawater pumped storage type;seashore pumped storage type