Sun

The ultimate source of virtually all energy on earth, the sun can be harnessed directly in a number of ways. Solar photovoltaic panels use the photons in light to generate electricity, while solar thermal can heat both water and space in homes, and passive solar can help comfortably regulate space heating in a building throughout the four seasons.

Passive Solar - By simply orienting a building to have its largest windows on the south side, the sun will provide much of the heating needs of the building in the winter. Up to 50 percent of a home's heating needs could be met through passive solar.

Active Space Heating - Mechanized systems can help circulate collected solar heat throughout a building. An example of such a system would be in-floor heating, where solar heat is collected and pumped below the floors of a building. Solar hot air systems can use fans to circulate heat throughout a building.

Photovoltaic Modules - More commonly known as solar panels, these use silicon crystals to generate electricity when sunlight strikes the cells, causing electrons to move. Modern solar panels are 18-30 percent efficient, converting that percentage of sunlight into electricity.

Solar Panels make electricity most effectively in direct sunlight with no shading, and in all seasons of the year. Because PVs do not make electricity when there is no sunlight, such as at night or on cloudy days, the energy must be stored for later use. The usual storage device is a rechargeable, deep cycle battery. Net metering systems store their electricity on the grid.

450 watts of Solar Photovoltaic Panels

Solar Hot Water - Heating water with an electric hot water heater is one of the largest electricity loads in any house, making roughly 25-30 percent of homes electricity bill. Solar thermal systems come in two main forms, as evacuated tubes or flat-plate collectors. Both have their advantage, and are up to 70 percent efficient.

Two banks of 10 evacuated tubes