What will we turn to next?

http://21stcentury.chinadaily.com.cn/article.php?sid=19863

A CRISIS. Rocketing oil prices. Going to war for it… The "it" in this case is energy.

So, what about the energy of the future that we use to keep our modernization going?

A leading US science website, LiveScience, published its list of the top 10 power sources that will run our world in the 21st Century (the indexes use a five-star measuring system, five being the best).

10. Solar

Solar energy requires no additional fuel to run. And it is pollution free. Sunlight can be captured as heat or changed into electricity. But, solar energy requires high initial cost. Also, productivity is subject to air pollution and weather.

Green: ☆☆☆☆☆

Cheap: ☆☆

Power: ☆

9. Coal

The major advantage of coal is that there is lots of it, enough to last the world for another 200-300 years at current rates of consumption. However, burning coal produces toxic impurities like sulfur and nitrogen. It also produces large amounts of carbon dioxide, a gas that contributes to global warming.

Green: ☆

Cheep: ☆☆☆☆

Power: ☆☆☆

8. Wind

Wind is one of the cleanest forms of energy and can generate power as long as the wind blows. The problem is that the wind doesn't always blow.

Green: ☆☆☆☆☆

Cheap: ☆

Power: ☆☆

7. Petroleum

Petroleum is a relatively cheap energy, but its use comes at the larger cost of environmental damage. Oil use produces large amounts of carbon dioxide.

And there's less and less petroleum left for us to explore.

Green: ☆☆

Cheap: ☆☆☆☆

Power: ☆☆☆☆

6. Biomass

Biomass energy involves releasing the chemical energy stored in organic matter such as wood, crops and animal waste. These materials are burned directly to produce heat or refined to create fuels like ethanol. But biomass energy produces large amounts of carbon dioxide.

Green: ☆☆

Cheap: ☆☆☆☆

Power: ☆☆☆

5. Hydroelectricity

It was generally believed that water energy was a rich natural resource that produces no pollution. Recent studies, however, suggest that hydroelectric dams can produce significant amounts of carbon dioxide and methane through the decay of submerged plant material. Another drawback of dams is that people often need to be relocated.

Green: ☆☆☆

Cheap: ☆☆

Power: ☆☆☆

4. Ocean Thermal

Energy Conversion

Oceans cover 70 per cent of the Earth, and water is a natural solar energy collector. Scientists are using the temperature differences between surface water heated by the sun and water in the ocean's chilly depths to generate electricity. The shortcoming of it is the cost.

Green: ☆☆☆☆☆

Cheap: ☆☆

Power: ☆☆☆

3. Nuclear

A huge amount of energy can be produced by either splitting or combining atoms - processes known as fission and fusion respectively. Most nuclear power plants now use fission, as fusion requires large amounts of energy to produce and maintain the necessary high temperatures. But new technologies are making it possible to use fusion too.

Green: ☆☆☆☆

Cheap: ☆☆

Power: ☆☆☆☆

2. Fuel cells

Hydrogen fuel cells might seem like the perfect alternative to fossil fuels. They can generate electricity using only hydrogen and oxygen and are pollution free. Unfortunately, most of hydrogen exists in molecules such as water. That means pure hydrogen must be produced with the help of other energy sources. That almost cancels its benefits.

Green: ☆☆☆

Cheap: ☆☆

Power: ☆☆☆

1. Antimatter

Antimatter is the twin of matter, made up of antiparticles that have the same mass as ordinary matter but with opposite atomic properties. When the opposed particles meet, they destroy each other and release large amounts of energy.

The problem with antimatter is that it can be only produced in laboratories, and now only in very tiny amounts, and at very high costs.

Green: ☆☆☆☆☆

Cheap: ☆

Power: ☆☆☆☆☆



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alternative: 替代品 antimatter: 反物质

antiparticle: 反粒子 biomass: 生物能量

carbon dioxide: 二氧化碳 conversion: 转换

ethanol: 乙醇，酒精 fission: 裂变

fusion: 聚变 hydrogen: 氢

hydroelectric: 水电的 impurity: 杂质

methane: 甲烷 molecule: 分子

nitrogen: 氮气 thermal: 热的

photoelectric: 光电的 sulphur: 硫磺

toxic: 有毒的