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	GETTING STARTED A Solar Panel Primer (A/B/X Class)
	As you know from the Regulations, while raycing, your bike has to carry a solar panel. The solar cell area can be as large as 1.6 m² and must be at least 0.15 m². This solar panel is no “decoration”. Compared to using batteries alone, it has the potential to more than double the power available to your drive motor during the Rayce! In this section, we'll discuss some of the issues of incorporating a useful solar panel into your bike design. You will find companies on the web or in the yellow pages that are solar cell producers. These companies generally manufacture complete “modules” - solar panels complete with cells, connectors, wiring harness, frame, and protective tempered glass cover plate - but some companies also provide “bare” cells ready to be soldered. The standard modules are designed for charging 12 volt batteries, and these can be wired in parallel or series to handle multiples of 12 volts. This means that 12, 24, or 36 volt drive systems can be supplied by the standard modules. Happily, these voltages are typical of the commercially available electric bicycle drive kits. The down side of standard modules is that they're heavy - they are designed to last decades in the harshest conditions, including hail. For this reason, they're much heavier than is needed or desired for solar bike raycing. Your team's riders know this trade-off well: bike racers are notorious for emphasizing lightness in their bike components, even at the cost of some durability. Given the choice of a 40 pound “bullet proof” solar array (“array” designates a working system of several modules) or 15 pounds of a more fragile array, your bikers will opt for the lighter system every time. And rightly so! Fortunately, some manufacturers offer “lightweight” production modules. BP Solar/Solarex sells an “MSX-Lite” series that's encapsulated (sealed) in plastic to save weight. Some other manufacturers offer similar options - call to see what's available. Check the cell area of the panels to see how many you can fit in your 1.6 m². Expect to pay as much or more for the plastic-encapsulated modules as for those built with tempered glass. As with light-weight bicycle components you'll pay a premium, but the final weight will be about half that of the standard modules. There's another option that can result in an even lighter array and somewhat reduced cost: build your own. This isn't for everyone; you'll have to do a bit more research into materials and methods, but the results can be worth the effort. I'd recommend buying at least one manufactured module to use as a design guide and to give yourself a chance to quickly “solarize” your bike. A standard module can be easily mounted on a bike to give you some experience with the solar part of your system. Plan on buying a manufactured module with the same type of cells as those you'd use if you built your own. Remember when buying or building that the Regulations refer to solar area: based on the area of the cells, not that of the total module. Whether you buy or build, you'll need to carefully consider whether or not you want to have the entire solar array deployed while you rayce. This is another trade-off issue: if you rayce with the full array, you'll have all of its power available while raycing, but you'll also have more need for power because of additional wind resistance and additional weight. If you decide to use a smaller array, you'll save weight and reduce aerodynamics, but you won't get as much solar energy. Probably the best way to decide which strategy to use is to get out there and see which lets you go faster. You could simulate the different arrays with plywood or some other material prior to constructing your solar system. Remember that whatever area you don't use on your bike, you can have for your stationary panels that you only use in the pits (total cell area of both panels cannot exceed the 1.6 m² maximum).

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