VOA慢速英语--新技术从河流和潮汐运动中获取能量

New Technology Harvests Energy from River and Tidal Movement

A number of companies have used the wind and sun to produce energy. Now, one company is using the force of flowing rivers and ocean currents.

The company is based in the U.S. state of Maine. It is called the Ocean Renewable Power Company, or ORPC. The company recently presented the new technology at an energy conference near Washington, DC.

Christopher Sauer is the chief executive officer and co-creator of ORPC. He says the technology was designed for small, rural communities that do not have easy access to power sources.

Taking energy from water movement

The ORPC technology is an energy generator¹ which can be put under water, called RivGen. It works in a series of steps. First, the generator is put in the middle of a steel cage. The cage goes on top of a wide boat with a flat bottom called a pontoon. Wheels – or, turbines – are attached to each side of the generator.

Once the pontoon boat is fixed² to one place, it is flooded with water. The pontoon, cage, and generator all sink to the bottom of the river. There, the river current turns the wheels and creates as much as 50 kilowatts³ of power.

CEO Christopher Sauer says the generator is not very tall, so it can work in water areas that are not very deep. Other companies are not able to work in shallow water, he adds.

And, Sauer says, the turbines are safe for the animals that live in the river.

"At the peak of salmon⁴ season, we had almost two million fish pass by this thing but at the end of all of that, we did not have a single fish injury that we knew about,” he said.

Sauer notes that another feature of the technology are “crossflow turbines.” They permit the turbines to move in the same direction, no matter what way the water is flowing.

Sauer says the turbines’ shape permits the generator to harvest power from tidal currents in the ocean. The company’s ocean turbine is called TidGen. It can create up to 600 kilowatts of electricity,. enough to power a small settlement.

Right now, the amount of power TidGen can harvest changes as the strength of the tide goes up and down. But ORPC workers are trying to make the power output steady. In time, they want TidGen power to be part of the main energy grid⁵.

CEO Christopher Sauer estimates ORPC’s current price is about 50 cents per kilowatt-hour. That price does not make the ORPC system competitive with natural gas. However, for small rural communities, diesel⁶ energy can cost more than $1 per hour. In these situations, energy from flowing water could be more economical.

I’m Phil Dierking.

Words in This Story

cage - n. a box made of wire or metal bars in which people keep animals or birds?

diesel - n. any liquid fuel used in diesel engines, whose fuel ignition takes place, without any spark, as a result of compression of the inlet air mixture and then injection?

generator - n. something that produces something?

grid - n. a metal frame with bars running across it that is used to cover an opening?

pontoon - n. a large hollow container filled with air that is used to make a structure (such as a boat, airplane, or bridge) float on top of water?

solar - adj. of or relating to the sun?

tidal - adj. of or relating to tides?

turbines - n. an engine that has a part with blades that are caused to spin by pressure from water, steam, or air

1 generator   

n.发电机，发生器

参考例句：

• All the while the giant generator poured out its power.巨大的发电机一刻不停地发出电力。
• This is an alternating current generator.这是一台交流发电机。

2 fixed   

adj.固定的，不变的，准备好的；(计算机)固定的

参考例句：

• Have you two fixed on a date for the wedding yet?你们俩选定婚期了吗？
• Once the aim is fixed,we should not change it arbitrarily.目标一旦确定，我们就不应该随意改变。

3 kilowatts   

千瓦( kilowatt的名词复数 )

参考例句：

• It's about 500 kilowatts per hour on average. 年用电量平均为每小时500千瓦。 来自商贸英语会话
• We have an emergency-standby electric generator with a capacity of 300 kilowatts. 我们有一台三百千瓦的事故备用发电机。

4 salmon   

n.鲑，大马哈鱼，橙红色的

参考例句：

• We saw a salmon jumping in the waterfall there.我们看见一条大马哈鱼在那边瀑布中跳跃。
• Do you have any fresh salmon in at the moment?现在有新鲜大马哈鱼卖吗？

5 grid   

n.高压输电线路网；地图坐标方格；格栅

参考例句：

• In this application,the carrier is used to encapsulate the grid.在这种情况下，要用载体把格栅密封起来。
• Modern gauges consist of metal foil in the form of a grid.现代应变仪则由网格形式的金属片组成。

6 diesel   

n.柴油发动机，内燃机

参考例句：

• We experimented with diesel engines to drive the pumps.我们试着用柴油机来带动水泵。
• My tractor operates on diesel oil.我的那台拖拉机用柴油开动。