Photovoltaic system and is typically less useful than a calculation of return on investment. While it is typically calculated to be between 10 and 20 years, the financial payback period can be far shorter with incentives. Due to the low voltage of an individual solar cell (typically ca. 0.5V), several cells are wired "(also see copper used in PV systems)" in series in the manufacture of a "laminate". The laminate is assembled into a protective weatherproof enclosure, thus making a photovoltaic module or solar panel. Modules may then be strung together into a photovoltaic array. In 2012, solar panels available for consumers
History of photovoltaic growth History of photovoltaic growth The history of photovoltaic growth includes previous forecast and annual deployment figures by country. Most PV deployment figures in this article are provided by the European Photovoltaic Industry Association in the "Global Outlook for Photovoltaics" report, the "Observatoire des énergies renouvelables" or EurObserv'ER's "Photovoltaic Barometer" report, and the IEA-PVPS (photovoltaic power systems) "Snapshot" and "Trends" report. In 2013, worldwide deployment of solar PV amounted to almost 40 GW (39,953 MW)—an increase of about 35 percent over the previous year. Cumulated capacity increased by 38 percent to more than 139 GW. This is sufficient to generate at