lesson 11-3 - Solar In a years time the Earth intercepts...

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Solar In a years time, the Earth intercepts solar energy in an amount that far exceeds (by many thousands of times) the quantity of energy that people consume at the global scale. Solar energy is, in fact, the ultimate origin for most of the other resources people use to generate energy, such as fossil fuels, biomass (non-fossil organic materials), and all water- and windpower. All of these resources are essentially storehouses of solar energy, in one form or another. While these resources are very important to current and future energy generation, the direct capture and use of solar energy is thought by some to be the best candidate to satisfy people's future energy needs while minimizing our impact on the global environment. Sunlight can be captured in many different ways and the solar energy it provides can be used to meet a variety of energy needs. In short, solar energy can be used to generate electricity, heat water, and heat, cool, and light buildings. Solar technology In general, solar energy can be used directly or indirectly, but the technologies involved in capturing or harnessing sunlight and its energy are many and complex. I will, therefore, only introduce the most common technologies: photovoltaics, passive solar, concentrating solar power, and solar heating and cooling. Photovoltaics (PV; also called "solar cells") . PV systems are used to convert sunlight (solar energy) directly into electricity. A PV cell acts as a solar collector and is made of semiconducting material that absorbs sunlight. As the sunlight is absorbed, it disturbs electrons and knocks them loose from atoms. Once loose, the electrons flow through the PV material and produce electricity. PV arrays (groups PV cells) can be set-up to produce electricity for individual homes, buildings, or entire power plants. A large quantity of PV arrays are required, however, to produce electricity at the power plant scale. A photovoltaic system co-located with nuclear power operation in Sacramento, CA. As the cost of photovoltaics continues to decrease, the technology becomes increasingly competitive for utilities. This 2- megawatt plant produces enough power to serve 660 Sacramento-area homes. The 1600 modules are spread across an 8094 square meter field in this very sunny region of California. Cost-competitive, utility-scale PV systems for intermediate peaking applications is one ultimate goal of stakeholder collaborations. Passive solar . Solar energy doesn't always need to be collected and converted to some other form to be used in a home/building. It is possible to design homes and buildings to exploit solar energy by passive means for heating, cooling, or daylighting. Passive solar technologies often involve large, south-facing windows, flooring or wall materials that absorb solar energy during
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the day and release its heat at night (called direct gain ), incorporating wall and roof angles that optimize solar exposure, or incorporating natural ventilation systems for cooling. Daylighting is
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lesson 11-3 - Solar In a years time the Earth intercepts...

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