太阳能激光电池效率达100％

使用直径约3英尺的小型抛物面反射镜，结合一种新的双层陶瓷磁盘，就可以产生激光，

把太阳的能量聚焦成超强激光束，这项技术又迈进一步。乌兹别克斯坦研究人员希望把太阳的能量聚焦为一束激光，用作可再生能源。这一方案需要使用3英尺宽的抛物面反射镜。

利用太阳光线，产生一束纯能量，这很久以来一直就是一些发明家的目标，从古希腊工程师阿基米德（聚光镜子摧毁入侵船只）到詹姆斯•邦德（James Bond）都是这样，就像影片《金刚钻》（Diamonds are Forever）和《谁与争锋》（Die Another Day）中基于空间的激光器。

但新的研究可能实现这一梦想，进行更实际的应用，就是用作可再生能源。

乌兹别克斯坦（Uzbekistan）的研究人员提出了一项计划，使用直径约3英尺的小型抛物面反射镜，结合一种新的双层陶瓷磁盘，就可以产生激光。

“有可能制成太阳能为动力的激光器，具有30％至40％的效率，”谢马克哈马特•派兹叶特（Shermakhamat Payziyev）说，他是塔什干（Tashkent）科学和生产协会（Scientific and Production Association）研究员。

派兹叶特说，他的方案要领先一步，有一个类似项目是日本研究人员2007年透露的，是用菲涅耳（Fresnel）玻璃透镜，而不是反射镜，他们创造激光用来燃烧海水中发现的镁。

派兹叶特说，他的方案刊登在本月的《可再生和可持续能源杂志》（Journal of Renewable and Sustainable Energy）上，是要利用太阳能创造激光，用于驱动电动汽车的电池。

“我们提出一个想法，就是如何有效地把太阳能转换成激光，”派兹叶特说。“原则上，它可以转换成电力，这需要使用聚光光伏组件，效率约为50％，在不久的将来会接近100％。”

太阳能为动力的激光器已经存在，处在实验运行阶段。但一直存在两个主要问题：消除反射镜产生的热量，并有效地把一种能量转换为另一种。

派兹叶特的装置解决了这两个问题。

当阳光照射陶瓷材料时，会激发电子，使它们发出特定波长的激光。为了控制这些热量，陶瓷盘要安装在散热器上面，通过散热器的是被泵抽的水。派兹叶特说，这一激光随后会在陶瓷表面再次进行反射弹跳，从而产生额外的效率。

听起来很酷，但这个项目确实有一些人持怀疑态度。

艾利•雅布龙诺维奇（Eli Yablonovich）是加州大学伯克利分校（University of California, Berkeley）电气工程和计算机科学教授，也是美国国家科学基金会（NSF：National Science Foundation）节能电子科学中心主任，他写了一篇论文，讨论非聚焦太阳能驱动的激光，那还是在1983年。他说，聚集激光器还没有真正设计出来。

“他们没有解决任何有用的问题，”雅布龙诺维奇说。来自太阳能的激光可以定向到太阳能电池，但增加的复杂性是不值得的。”

雅布龙诺维奇认为，先进的太阳能集热器更划算，可用于能量收集，而他们合作成立的阿尔塔设备公司（Alta Devices）是一家硅谷公司，正在制造高效率的太阳能光伏电池。

派兹叶特说，尽管存在这些障碍，他提出的太阳能为动力的激光也会取得进展。他说，它可用于合成大批量的纳米粒子和纳米粉，用于制造复合材料、超导体、太阳能电池和先进的油漆或涂料。

他工作的场地是在世界上最大的太阳炉，就是所说的乌兹别克斯坦大太阳炉（Big Solar Furnace）。

本文为麻省理工《科技创业》原创文章，未经书面许可，严禁转载使用。

Harnessing the sun's rays to produce a beam of pure energy has long been the goal of inventors from the ancient Greek engineer Archimedes (focused mirrors to destroy invading ships) to James Bond villains (space-based lasers of "Diamonds are Forever" and "Die Another Day").

But new research may realize the dream for a more down-to-Earth use: renewable energy.

A researcher in Uzbekistan has proposed a plan using small parabolic mirrors about 3 feet in diameter, combined with new two-layer ceramic disks to produce laser light.

"It is possible to make solar-powered lasers with the efficiency of 30 to 40 percent," said Shermakhamat Payziyev, a researcher at the Scientific and Production Association "Akadempribor" in Tashkent.

Payziyet said his proposal is a step beyond a similar project unveiled by Japanese researchers in 2007 which used a glass Fresnel lens instead of mirrors to create a laser to combust magnesium found in seawater.

Payziyet says his plan, published this month in the Journal of Renewable and Sustainable Energy, would use the sun's energy to create a laser to power electric cells.

"We proposed an idea how to convert effectively the solar light into the laser," Payziyet said. "In principle it can be converted into electricity by using concentrating photovoltaic modules with the efficiency of about 50 percent or closer to 100 percent in the near future."

Solar-powered lasers already exist on an experimental basis. But there have always been two major issues: removing the heat generated by the mirrors and the converting one kind of power to another efficiently.

Payziyet's unit tackles both.

When sunlight hits the ceramic material, it excites the electrons and causes them to emit laser light of a specific wavelength. To control the heat, the ceramic disk would be mounted atop a heat sink through which water would be pumped. The laser light would then take another reflective bounce through the ceramic surface, which produces an extra amount of efficiency, Payziyet said.

Sounds cool, but the project does have some doubters.

Eli Yablonovich, professor of electrical engineering and computer sciences at the University of California at Berkeley and director of the NSF's Center for Energy Efficient Electronics Science, wrote a paper about unfocused solar powered lasers back in 1983. He says focused lasers haven't really worked out.

"They don't solve any useful problems," Yablonovich in an email. Laser energy from the sun "can be directed into a solar cell, but the added complexity is not worth it."

Yablonovich believes that advanced solar collectors are a better bang for the energy-collecting buck and co-founded Alta Devices, a Silicon Valley firm which is making high-efficiency photovoltaic solar cells.

Despite the obstacles, Payziyet says his proposed solar-powered laser will get off the ground. He says it can be used to synthesize industrial quantities of nano-particles and nano-powders used to manufacture composite materials, superconductors, solar batteries and advanced paints or coatings.

He works at the site of the world's largest solar furnace, known as the Big Solar Furnace in Uzbekistan. It sounds like a bad guy's lair, but Payziyev says he's no Bond villain out to create a death ray.

"It is obvious that any new idea will be considered regarding its use in military purposes at first, but I am not supporter of this bad idea," he said. "The solar laser is a promising way in the use of renewable energy as an ultimate energy source for peaceful purposes."