Skylights for lower energy use

Daylighting - The practice of letting natural light into a building to reduce energy costs

What it is all about:

Windows and skylights are used to illuminate a home or office to reduce use of light bulbs and lower overall energy consumption.

When you combined energy efficient windows with a proper design, the use of artificial lighting will be reduced during the daytime hours without needed to use more energy heating/cooling the space.

How to implement:

South facing windows are best for day light and maintaining a comfortable temperature throughout the different seasons. The south facing windows will let plenty of light into he home during winter without letting in direct light in the summer. North windows are also and okay option for day light, but east and west will let in too much direct light. The east and west windows are necessary for cross ventilation however.

Does it work:

 Of course! When a building maximizes its natural light while keeping seasonal temperature change to a minimum without using energy it is always a win. If you need more plenty studies have been conducted about humans and work productivity in a naturally lit environment. Humans thrive in natural light.

Terms to be familiar with:

Tubular Daylighting Device (Tubular Skylight): Something like a compound skylight. A tubular model will use mirrors and lenses to spread light within a building.

Lighting Power Density: a means to measure the electrical lighting installed in a building with a mathematical formula.

Indirect Lighting: Lighting that is a result from reflection...like some of the light from a tubular skylight.

Building Envelope: The external boundary of a building. Walls, entrances, windows, and roofs.

What does Photovoltaic mean and why is it useful

Photovoltaics

Photovoltaics is the direct conversion of light into electricity at the atomic level. Some materials  
exhibit a property known as the photoelectric effect that causes them to absorb photons of light and release electrons. When these free electrons are captured, an electric current results that can be used as electricity.

The photoelectric effect was first noted by a French physicist, Edmund Bequerel, in 1839, who found that certain materials would produce small amounts of electric current when exposed to light. In 1905, Albert Einstein described the nature of light and the photoelectric effect on which photovoltaic technology is based, for which he later won a Nobel prize in physics. The first photovoltaic module was built by Bell Laboratories in 1954. It was billed as a solar battery and was mostly just a curiosity as it was too expensive to gain widespread use. In the 1960s, the space industry began to make the first serious use of the technology to provide power aboard spacecraft. Through the space programs, the technology advanced, its reliability was established, and the cost began to decline. During the energy crisis in the 1970s, photovoltaic technology gained recognition as a source of power for non-space applications.

Thanks to NASA for putting it so well...you can find the rest if you would like to follow the link.

http://science.nasa.gov/science-news/science-at-nasa/2002/solarcells/
http://www.alternative-energy-news.info/technology/solar-power/photo-voltaics/