(JP11350463-A)      Caissons (6) containing pump-turbines (20) therein and offshore dams (5) are provided in the offing of a land (2), the submergence of which is to be prevented when the surface of the sea rises due to a global warming gas, in such a manner that the caissons and dams extend in parallel with the coastline of the land, partition dams (7) being provided so as to connect the offshore dams and the coastline together to thereby make ponds (8). The water level of each pond is kept to be lower than a preset level (11), which is several meters lower than an average level of the surface of the ocean (1), by an operation of the pump-turbines to enable not only the submergence of the coastal land to be avoided, but also the area of the land to expand offshore instead.    A high-efficiency pumped storage power generation is conducted in which the development of tidal energy and seawater pumped storage power generation are combined with each other by carrying out tidal wave pumped storage power generation, in which the head of a water turbine is larger than the lift of the pump, and which comprises lowering the water level of the pond to a level further lower than the preset level by an operation of the pump at low tide in the night time, and introducing the seawater in the ocean into the ponds by an operation of the water turbine at high tide in the daytime to increase the water level of each pond up to the set level.    ADVANTAGE -   Economical efficiency is given to the system equipment.    (EP1010811-A1)      Caissons (6) containing pump-turbines (20) therein and offshore dams (5) are provided in the offing of a land (2), the submergence of which is to be prevented when the surface of the sea rises due to a global warming gas, in such a manner that the caissons and dams extend in parallel with the coastline of the land, partition dams (7) being provided so as to connect the offshore dams and the coastline together to thereby make ponds (8). The water level of each pond is kept to be lower than a preset level (11), which is several meters lower than an average level of the surface of the ocean (1), by an operation of the pump-turbines to enable not only the submergence of the coastal land to be avoided, but also the area of the land to expand offshore instead.    A high-efficiency pumped storage power generation is conducted in which the development of tidal energy and seawater pumped storage power generation are combined with each other by carrying out tidal wave pumped storage power generation, in which the head of a water turbine is larger than the lift of the pump, and which comprises lowering the water level of the pond to a level further lower than the preset level by an operation of the pump at low tide in the night time, and introducing the seawater in the ocean into the ponds by an operation of the water turbine at high tide in the daytime to increase the water level of each pond up to the set level.    ADVANTAGE -   Economical efficiency is given to the system equipment.    (US6283673-B1)      Caissons (6) containing pump-turbines (20) therein and offshore dams (5) are provided in the offing of a land (2), the submergence of which is to be prevented when the surface of the sea rises due to a global warming gas, in such a manner that the caissons and dams extend in parallel with the coastline of the land, partition dams (7) being provided so as to connect the offshore dams and the coastline together to thereby make ponds (8). The water level of each pond is kept to be lower than a preset level (11), which is several meters lower than an average level of the surface of the ocean (1), by an operation of the pump-turbines to enable not only the submergence of the coastal land to be avoided, but also the area of the land to expand offshore instead.    A high-efficiency pumped storage power generation is conducted in which the development of tidal energy and seawater pumped storage power generation are combined with each other by carrying out tidal wave pumped storage power generation, in which the head of a water turbine is larger than the lift of the pump, and which comprises lowering the water level of the pond to a level further lower than the preset level by an operation of the pump at low tide in the night time, and introducing the seawater in the ocean into the ponds by an operation of the water turbine at high tide in the daytime to increase the water level of each pond up to the set level.    ADVANTAGE -   Economical efficiency is given to the system equipment.