Solar Primer continued...

Advantages of Higher Voltages

In all power systems we have to move electricity from one place to another. The transfer is not 100% efficient, and we have to take care to minimize the power losses en route. In wire, the loss of electrical power is a factor of the resistance of the wire, and the amount of current going through it. If we use higher voltages, our current is less, so power losses will be lower.

Solar Energy - Basic Information

Solar Modules: In the simplest terms, solar modules convert sunlight directly into electricity.

Essentially four technologies are available commercially:

1. Single Crystal Silicon Cells
   - cells are sliced from a single silicon ingot - see Siemens brochure
   - the most efficient available commercially (~16% conversion efficiency)
   - offered by most of the major manufacturers including SIEMENS Solar    Industries
   
   
2. Polycrystalline Cells
   - silicone is melted together and sliced into cells
   - the second most efficient technology (~13% conversion efficiency)
   - less expensive manufacturing process
   - Solarex is a big manufacturer of this type of cell
   
   
3. Amorphous technology
   - Similar to what is in toys and consumer electronics
   - Silicone material is spread onto a metallic backing
   - Inexpensive but least efficient alternative (~8% efficient)
   - Unisolar modules use this technology
   
   
4. CIS (Copper Indium Diselenide)
   - the latest development in solar cells - thin film technology
   - approximately 11% efficient
   - Siemens is pioneering the commercialization of this technology
   - expected that future advances in efficiencies will come in this area

Largest Companies in the Business:

1. Siemens Solar Industries (U.S. subsidiary of Siemens Electric)
   - The biggest manufacturer - 25% of all panels installed worldwide
   - Offers the longest warranties in the business (25 years on sizes above    46 Watts).
2. BP (British Petroleum)
3. Solarex
4. Unisolar

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