Biodegradable mems. Vocabbox. A lot of machines made by physicists are used in medicine now, страница 10

The market for SiGe products is predicted to grow enormously. Indeed, Strategies Unlimited, a market-research company, forecasts that the wireless and digital SiGe market will reach $1.8 billion by 2005. Furthermore, SiGe gives us the opportunity to study fundamental physics in a new materials system that has different properties from the III-V compounds and conventional silicon systems.

Comprehension check

What do you think?

1.  Why does silicon account for over 98% of sales in the global semiconductor market?

2.  What materials have allowed silicon to dominate over other faster materials?

3.  How will the cost of the transistors drop?

4.  What allows computers to double up in speed?

5.  Can silicon devices compete with the other semiconductor materials in all areas?

6.  How can we open up a number of new applications of silicon?

7.  Are many SiGe products already available?

Activity

Draft a brief report on the design of a wide range of electronic devices that are faster than silicon.

UNIT 11

ELECTRICITY  WAREHOUSE

WILL  SHIFT  THE  BALANCE  OF  POWER

Vocabbox

noun collocations

§  a regenerative fuel cell

§  the only by-product

§  small-scale generators

§  electricity warehouse

§  a giant-rechargeable battery

§  a reversible electrochemical reaction

§  a proton exchange membrane

§  the cleanest generating plant

§  a commercial regenerative facility

verb collocations

§  make electricity as easy to store as oil

§  allow electricity to be stockpiled

§  put electricity in

§  store energy

§  play no part in the reaction

§  be entirely closed

§  allow better use to be made of

Pre-reading task

Before you read, answer the following question:

Can electricity be stored?

Reading

Read the text. As you are reading make yourself

1.  a terminology list

2.  a list of major facts.

A new type of “regenerative” fuel cell could revolutionize the energy industry by making electricity as easy to store as oil. Most fuel cells generate electricity by combining hydrogen and oxygen, with water as the only by-product, whereas the regenerative fuel cell stores energy in tanks of salt solution. Work on this kind of fuel cell is being” carried out by Innogy, which is currently part of National Power in the UK but is due to be demerged soon.

By allowing electricity to be stockpiled, Innogy’s Regenesys system will let small-scale generators compete with large centralized plants. “We like to think of this as an electricity warehouse rather than a giant - rechargeable battery” said David Trelfall, director of the project. “Just like a warehouse it will allow generators to put electricity in when the prices are cheap and to sell it again when the prices are high.”

Regenesys uses sodium bromide and sodium polysulphide salts, which are abundant and safe. A reversible electrochemical reaction stores energy in the salts, which are separated by a proton exchange membrane. The electrodes play no part in the reaction, unlike a battery, where the size and shape of the electrodes limit the performance.

The system is also entirely closed, so there are no discharges into the local environment. The Regenesys technology offers operators the choice of building fewer power stations and allows better use to be made of the cleanest generating plant,” says Brian Count, chief operating officer at Innogy.

Innogy started construction of a commercial regenerative facility in Cambridgeshire in August. When it is completed in 18 months’ time, the plant will be capable of supplying 15 MW of power, enough for 150000 people. It will be used to provide a “black-start” service to restore the grid after a failure. A similar plant is being planned for Tennessee Valley Authority in the US.

Comprehension check

Answer the following questions: