They Use Fiber for That?

Contractors who do fiber optic projects should be familiar with most of the usual applications, such as telecom, cable television, local area networks and closed-circuit television (CCTV), but may not have much experience with the more unusual or newer applications. At The Fiber Optic Association, we get calls from contractors involved with some of these unusual projects that may not be as familiar but offer unique opportunities. This noncontinuous series of columns will examine some of these applications from a technical standpoint and as business opportunities.

The first application is in alternative-energy projects. While the price of oil and gasoline keep pushing us toward alternative energy, the tragic events at the Fukushima nuclear plant in Japan demonstrate why nuclear power may be hard to make safe, especially in earthquake-prone areas, such as California, where I live. Instead, California is pushing utilities to develop and use more alternative-energy sources. Fortunately, we have a lot of sunshine and wind to harness into energy. We even have a lot of ocean waves, another source of energy that can be tapped, but that looks like it’s many years in the future.

Solar and wind power is used now. I am not talking about solar on a residential or commercial scale; these projects are many megawatts in output spread out over not just acres but square miles of desert land. The wind projects don’t look like the ones from old western movies either. They are giant towers designed to adapt to the speed and direction of the wind.

Solar and wind projects use technology to maximize efficiency. Some solar projects are photovoltaic, converting sunlight directly to electricity, but thermal solar is becoming more popular. Thermal solar systems use mirrors to follow the sun and concentrate sunlight onto a tube to create a lot of heat, generating steam, which runs a turbine. It’s very much like a conventional power plant, but it doesn’t burn fossil fuels and emit pollution.

Thermal solar-power systems can even produce electricity after the sun has set by storing heat for use after dark. Some of these systems heat a liquid in the heat exchanger, but a new type actually uses table salt. The salt is heated in a quartz tube until it melts, then it is stored underground in a heat exchanger, where it creates steam to run a turbine generator. The salt holds much more heat than liquids, allowing the storage of enough heat for 24-hour operation. This system, developed by Rocketdyne for the International Space Station but never used, can be compared in design to a nuclear reactor. However, in this salty case, if you have a meltdown, you can scrape up the waste and use it on your dinner!

Another similarity of these thermal solar systems to nuclear—and conventional—power plants is their need for constant monitoring and control. Mirrors need to move to follow the sun. The movement of the liquid in the heat exchanger needs to be controlled to keep the temperature relatively constant. The generators need monitoring and control on both the steam and electrical sides. Of course, the whole facility is monitored by CCTV cameras.

What is different about one of these solar facilities is the scale of the project, as they cover thousands of acres of land. That means that the fiber optic network connecting all this monitoring and control hardware is immense. One operator of a thermal solar plant in the California desert said there is more than 200 miles of fiber optic cable in the network. With that size, the fiber has to be all single-mode to cover the distances involved, making it more like a metropolitan network, just located in the middle of the desert.

Large wind farms have a similar problem. Every windmill needs monitoring and control for aligning the blades to maximize the power from the wind. The blade size and generator create extreme stress on the components, so it is important to monitor the equipment’s operation, including keeping tabs on vibration that can indicate problems. Each tower must be connected to a central monitoring facility, which also needs single-mode fiber and is a long distance from many towers.

These are two examples of where electrical contractors are well suited for the fiber installation, as both solar and wind power require knowledge of electrical systems and outside plant fiber optics. Becoming knowledgeable about these alternative-energy sources is good for business.

Since both solar and wind systems generate electricity for the electrical grid, they become part of the grid-management problem that is currently being addressed by what is being called smart grid technology. The smart grid also depends on fiber, but that is a topic for a future column.

HAYES is a VDV writer and educator and the president of The Fiber Optic Association. Find him at

About the Author

Jim Hayes

Fiber Optics Columnist and Contributing Editor
Jim Hayes is a VDV writer and trainer and the president of The Fiber Optic Association. Find him at .

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