Not only is the world ' s first commercial wavefarm due to be switched on and connected to the electricity grid inportugal this summer ? but an even newer type of wave - power generatorcould drastically reduce the cost of extracting energy from the sea 这不仅因为今年夏天在葡萄牙世界上第一座海浪发电厂将要开始投入运作并接入电网,而且一种更新型号的海浪能发动机可以极大地降低从海洋获取能源的成本。