A project started in 2002 by Verdant Power Inc. sawtidal turbines在纽约东河10米深的地方，利用长岛湾可靠的潮涌。

潮汐涡轮机每天在4节的水流中以35-40转的速度无声旋转18个小时，消除了人们对可再生能源的两个更常见的抱怨:噪音和不可预测性。在潮水达到高峰的短暂停滞期后，海水开始回流，导致涡轮机自动旋转，重新开始发电。

The success of that pilot project earned Verdant Power the first ever commercial licence in the U.S. for tidal power generation, a green light for the installation of up to 30 turbines over 3 years that will produce 1 megawatt of power, or enough for 900 homes. The pace of the project is being intentionally slowed in order to monitor any effects on marine life.

Success of this phase could lead to the installation of up to 300 turbines, and give Verdant Power a leading role in changing the way we generatehydroelectricity.

要使潮汐能发电发挥作用，潮汐发电的最高潮位必须不低于5米，最理想的情况是要有一个大海湾，可以储存流入的水。Global capacity fortidal power每年的发电量估计在2.5到3万亿千瓦时之间，大约是加拿大总发电量的10倍。

以芬迪湾为例，每6小时有1000亿吨海水进出，平均涨潮超过16米。换句话说，这是在同一6小时内流经世界所有淡水河流总水量的4倍多。

One of the benefits of tidal surges compared to rivers is the stoppage of flow during high and low tides for installation and maintenance. However, the world’s rivers are a source of power that has not been dismissed; Verdant Power is currently working with the Ontario Government on a pilot project for the St. Laurence river starting in 2015.

位于加拿大一侧的圣劳伦斯河项目将开始安装两台涡轮机，预计将为安大略省康沃尔市提供110千瓦的电力。

Studies of fish habitat in the East River project showed absolutely no negative impacts, and the clear water of the St. Laurence will facilitate the installation of cameras to monitor fish migration, offering valuable insight into the struggling St. Laurence sturgeon population.

Tidal and river turbines may change the way we harness hydroelectric power

Harnessing the power of flowing water is anything but a new technology; what is new is the benign ecological effects of free-standing underwater turbines compared to the damming of rivers.

While power from hydroelectric dams is certainly renewable, it is by no means clean. There are many social and ecological repercussions that come with it:

  • The destruction and relocation of communities upstream and downstream.
  • The blocking of fish migratory routes and the extinction of species.
  • Blocking the flow of river sediment that replenishes soils.
  • 水库中腐烂的植被释放出甲烷等温室气体。

As methane rises to the surface, oxidization causes it to change into carbon dioxide, a less harmful gas. So rather than at the surface of reservoirs, 95% of the problem is at the dam itself where methane-rich deep water goes through the high-pressure environment of turbines and spillways.

According to the Intergovernmental Panel on Climate Change, methane has a warming impact 72 times higher than carbon dioxide. The world’s largest dams (dams over 15 metres tall) release a combined 104 million metric tons ofmethane gasannually.

There is no un-doing to be done of the damage caused by existing dams, but perhaps the future harnessing of hydroelectric power won’t come with the same costs if free standing turbines become the norm.