Photovoltaic system (or PV) is the field of technology and research related to the application of solar cells for energy by converting solar energy (sunlight, including ultra violet radiation) directly into electricity. Due to the growing demand for clean sources of energy, the manufacture of solar cells and photovoltaic arrays has expanded dramatically in recent years.

Photovoltaic production has been doubling every 2 years, increasing by an average of 48 percent each year since 2002, making it the world’s fastest-growing energy technology. At the end of 2008, the cumulative global PV installations reached 15,200 megawatts, a 94% annual increase. Roughly 90% of this generating capacity consists of grid-tied electrical systems. Such installations may be ground-mounted (and sometimes integrated with farming and grazing) or built into the roof or walls of a building, known as Building Integrated Photovoltaic or BIPV for short.

Net metering and financial incentives, such as preferential feed-in tariffs for solar-generated electricity, have supported solar PV installations in many countries including Australia, Germany, Israel,[9] Japan, and the United States.

Currently there is 3 main technologies that dominate in the PV market:

Polycrystalline cells:

Polycrystalline cells are produced by pouring hot, liquid silicon into square molds or casts. The silicon is cooled to form solid blocks, which are sliced like single-crystalline silicon. The obtained mass is cut into rectangular rods which are sliced into thin wafers, forming a 'patchwork quilt' of single-crystalline silicon molecules. Since this technology is the best known and relatively cost-effective, polycrystalline cells remain the most commonly used.

Monocrystalline cells:

Monocrystalline cells are created in a similar process as mentioned above but the ingots are manufactured according to the very complicated Czochralski process. The ingots have the same, strictly desired crystal orientation through their whole length. The shape of the cross section of an ingot is circular. Since it is a waste of surface to use round cells beside each other, a rectangular like shape is cut out of the ingots's cross section. The corners are left round because it would be too expensive to throw out the obsolete material after cutting out a full square from the inside of a circle cross section.

Thin-film technology cells:

Thin-film technology cells are printed on glass in many thin layers, thus forming the desired modules. Manufacturing them requires less material than producing crystalline cells because no cutting is needed. In addition they only require laminating on one side since they are “glued” to a glass pane on the other side during the production process.

Concentrated solar power systems (CPV)

CPV systems use optics to concentrate a large amount of sunlight onto a relatively small area of specially designed solar photovoltaic material that can work with highly concentrated light energy. Unlike traditional, more conventional PV systems, CPV systems concentrate light and can produce the same power from a much smaller area of solar cells. For this reason they may be able to produce electricity for less than conventional PV can.