Solar glossary
Key terms in solar power production and solar energy from A to Z
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Amorphous solar cells | Amorphous or thin-film cells entail the precipitation of a layer of silicon on glass or other substrate. Such layers are less than 1 um thick (the thickness of a human hair is 50-100 um), which means less material and, in turn, reduced production costs. On the other hand, amorphous cells are much less efficient than other types. They are mainly used in low-power devices (watches, calculators) or as façade elements.
See also:
Batteries | As electricity generated by photovoltaic plants varies depending on the solar radiation, batteries are used to store the surplus energy. This ensures the supply of electricity over an extended period of time and increases the self consumption.
See also Self consumption>>
Building-integration | The term building-integration is used of solar power facilities built or integrated into a structure, of which they serve as a component – whether façade or roof cladding – while at the same time producing electricity. The most aesthetically pleasing solution, this form of photovoltaic facility is also the most widely accepted.
Capacity | A solar power facility’s capacity is expressed in kilowatt peak (kWp), or the performance of a solar facility in full sunshine (1000W/m2) and a cell temperature of 25 degrees.
See also Output >>
Collector | Instead of electricity, collectors produce heat for hot water or heating by absorbing solar radiation, converting it into heat, and feeding this product into a heat reservoir.
Cost-covering remuneration for feed-in to the electricity grid (CRF) | The CRF is Switzerland’s state feed-in tariff for renewable resources. It is a support scheme guaranteeing a fixed price per kilowatt hour to plants that have been through the application process. Operators of small photovoltaic installations (<10 kWp) receive instead of the CRF a one-off contribution of approx. 30% of the investment costs. Switzerland is not the only country to support solar power production with a feed-in tariff.
See also Feed-in >>
Depreciation method | The Edisun Power Group uses a linear depreciation method under Swiss GAAP FER over 25 years for its solar power facilities, as per its feed-in agreements with individual countries. Annual depreciation is thus 4% of the procurement cost, resulting in a continuous, linear charge to the income statement over the depreciation period.
Elevated modules | Solar modules installed on flat roofs are typically elevated: they are mounted on metal posts and/or cement pillars at an angle of roughly 30 degrees.
Façade-mounting | Solar modules and collectors can be mounted on a façade either at an angle or parallel to the wall.
Feed-in | In specialist parlance, electricity from a solar or other power plant is said to feed into the public grid.
See also Feed-in tariff at cost >>
Grey energy | Grey energy is the amount of energy needed for the manufacture, transport, storage and sale of a product. It takes an average of two years for a solar power plant to match this figure in its own production.
Grid parity | Grid parity is a technical term for the moment at which electricity from solar power plants can be produced for the same price at which conventionally generated electricity is sold to the consumer.
Ground-mounted photovoltaic plants | Ground-mounted photovoltaic plantsare solar power plants installed neither on a roof nor on a façade, but on unfarmed arable land or fallow fields.
Insolation in France | The average annual insolation in France is some 1200 kilowatt-hours (kWh) per square metre on a horizontal surface.
Insolation in Germany | The average annual insolation in Southern Germany is some 1100 kilowatt-hours (kWh) per square metre on a horizontal surface.
Insolation in Spain | The average annual insolation in Spain is some 1600 kilowatt-hours (kWh) per square metre on a horizontal surface.
Insolation in Switzerland | The average annual insolation in Switzerland is some 1100 kilowatt-hours (kWh) per square metre on a horizontal surface, while areas at greater altitude may see values above 1400 kWh. There is thus sufficient insolation throughout Switzerland to permit the efficient operation of solar power plants.
Inverters | An inverter is an electrical device capable of converting DC voltage into AC voltage, or direct current into alternating current. Because they produce direct current, on-grid solar power facilities always require an inverter to convert their product into alternating current to be fed into the grid. Only off-grid facilities used to power appliances requiring direct current are not typically equipped with an inverter.
See also Off-grid facilities>>
Module | See also Panel >>
Monocrystalline solar cells | Monocrystalline solar cells have an efficiency of 14 to 20% and are manufactured using highly pure semiconductor material. Monocrystalline rods are drawn from molten silicon and sawn into thin wafers, a production method that guarantees relatively high efficiency.
Off-grid facilities | Solar power plants not connected to the public power grid are said to be off-grid. They are installed in places where connection to the power grid is unadvised or impossible for economic or technical reasons, such as mountain cottages, vacation homes, emergency telephone pillars or parking lot metres, among other places. They typically require a battery to ensure power supply in the event of inclement weather or during the night. Such batteries are charged with solar energy during the day. Off-grid facilities may be used to power appliances requiring direct current, such as radios, televisions and lighting, or, by way of an inverter, to supply power to devices with typical grid voltage of 230 V.
See also Inverters >>
On-grid facilities | On-grid facilities are solar power plants that are connected to the public power supply, which means that the electricity produced by such plants flows directly into the common power grid.
See also Feed-in >>
Output | The electricity output from a solar power facility connected to a grid can be read in kilowatt-hours directly from the supply meter. Depending on their region, exposure and mounting, as well as on the quality of their components and their calibration, solar power facilities in Central Europe yield an average output of 800 to 1400 kWh per kWp and year. In just one hour, enough solar energy reaches the Earth to meet the entire human consumption for a year.
See also Capacity >>
Panel | Panels, also called solar power or photovoltaic modules, consist of solar cells that convert sunlight into electricity. A panel comprises several solar cells wired in series and protected against the environment by a glass, plastic and metal housing. They are thus suitable as components of small and large solar facilities alike.
Photovoltaic facilities | A photovoltaic facility is a solar power plant, which consists of several solar modules that convert sunlight into direct current. Produced by on-grid facilities, direct current can be converted into the 230 V alternating current typical of power grids. Depending on the way they are mounted, solar power facilities can also perform additional functions, including rendering roofs impermeable, providing protection from the sun, improving a building’s appearance etc.
Photovoltaic module | See also Panel >>
Photovoltaics | "Photovoltaics" is the technical term for the entire field of solar power. It is abbreviated to PV, as in PV module, PV facility etc.
Polycrystalline solar cells | Polycrystalline solar cells have an efficiency of 13 to 16% and are cheaper to manufacture than the monocrystalline variety. Liquid silicon is cast in ingots, which are in turn sawn into wafers. As the material solidifies it forms variously sized crystal structures with defects appearing on the gaps in its lattice.Such crystal defects reduce the efficiency of a solar cell.
Potential for solar power | More than a third of Switzerland’s electricity demand can be sustainably supplied with the technology currently available in installations at existing sites.
Profit zone | Because of linear depreciation and progressive retirement of debt, new facilities are heavily encumbered during their first service years, and accordingly post losses. From the middle of their useful life on, however – that is, about the seventh or eighth year – facilities reach the profit zone and contribute to a positive consolidated result. In addition, the trend towards an increasing average size of facility further enhances this system of depreciation and debt retirement.
Retirement of debt | As a rule, we finance our facilities with 20% equity and 80% debt, the latter procured either by way of direct project financing from banks or by bond issues. Debt is typically to be amortized over ten to 15 years. In the main, amortization and interest on debt constitute a percentage of the base. For example, if we borrow CHF 100,000 at an annual amortization rate of 10%, we pay off CHF 10,000 the first year, CHF 9,000 the second and so on, since the base is steadily reduced by the amount of the repayments.
Roof-integrated mounting | Roof-integrated mounting involves the removal of a sufficient number of tiles from a pitched roof to allow collectors or solar modules to be mounted directly onto the laths beneath.
Roof-mounting | The solar modules are mounted on an existing tiled roof, or more precisely on a construction that is itself mounted on the tiles of a given roof, rather than directly on its laths.
See also Roof-integrated installation >>
Self consumption | «Self consumption» is defined as the part of the self-produced power by the photovoltaic facility that is used immediately on-site and not being fed into the public electricity network. Depending on the country, you have to pay a contribution on the self consumption of the solar power. This is not the case in Switzerland.
See also Feed-in >>
Smart grids | Smart or "intelligent" power grids make possible communication concerning consumption, transmission capacity and production, as well as enabling the parties involved to exercise partial control.
Solar cells | Solar cells are made of either crystalline or amorphous silicon and can convert sunlight into electricity.
Solar heat | Solar radiation can be converted into either electricity or heat. Facilities used to generate heat consist of collectors, and their product can be used for water and space heating alike. This glossary covers only its conversion into electricity.
Solar module | See also Panel >>
Solar power facility | A solar power facility consists of several solar modules (panels) that convert sunlight into direct current. Produced by on-grid facilities, direct current can be converted into the 230 V alternating current typical of power grids. Depending on the way they are mounted, solar power facilities can also perform additional functions, including rendering roofs impermeable, providing protection from the sun, improving a building’s appearance etc.
Solar thermal power | Solar radiation can be converted into either electricity or heat. Facilities used to generate heat consist of collectors, and their product, which is known in specialist parlance as solar thermal power, can be used for water and space heating alike.
See also Collectors >>
The sun's energy | In just one hour, enough solar energy reaches the Earth to meet the entire human consumption for a year.
Thin-film cells | Thin-film cells are some 100 times thinner than monocrystalline and polycrystalline solar cells. They are typically made of amorphous silicon, copper indium gallium diselenide (CIGS) or cadmium telluride (CdTe). While they are less efficient than crystalline cells, they are less expensive to manufacture, requiring as they do less material and energy.
See also:
Sources:
http://www.dgs.de
http://www.swissolar.ch
http://www.solarwirtschaft.de
http://www.qcells.de/de/solarenergie/solar-glossar/index-66.html
http://www.epia.org
http://de.wikipedia.org
