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Perovskites may sound like perogies or piroshkis, but no high-carb-cheese-and-potato-flavor-pocket can do what they do. They’re minerals that can do the same party trick as many of your favorite childhood toys and models (such as the classic AMT Interplanetary UFO Mystery Ship; oh, how I miss you) and teenage trinkets such as glowsticks and “neon” rave necklaces: that is, they absorb and emit light. But perovskites emit more of the solar spectrum than does silicon. So much so that scientists at the University of Cambridge have reported that they can now make ultra-thin, stable layers of halide perovskites……..Continue reading….

By Malcolm Azania

Source: New Atlas

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Critics: 

A solar cell, also known as a photovoltaic cell (PV cell), is an electronic device that converts the energy of light directly into electricity by using the photovoltaic effect. It is a type of photoelectric cell, a device whose electrical characteristics (such as current, voltage, or resistance) vary when it is exposed to light. Individual solar cell devices are often the electrical building blocks of photovoltaic modules, known colloquially as “solar panels”.

Almost all commercial PV cells consist of crystalline silicon, with a market share of 95%. Cadmium telluride thin-film solar cells account for the remainder. The common single-junction silicon solar cell can produce a maximum open-circuit voltage of approximately 0.5 to 0.6 volts. Photovoltaic cells may operate under sunlight or artificial light.

In addition to producing solar power, they can be used as a photodetector (for example infrared detectors), to detect light or other electromagnetic radiation near the visible light range, as well as to measure light intensity. The operation of a PV cell requires three basic attributes:

• The absorption of light, generating excitons (bound electron-hole pairs), unbound electron-hole pairs (via excitons), or plasmons.
• The separation of charge carriers of opposite types.
• The separate extraction of those carriers to an external circuit.

There are multiple input factors that affect the output power of solar cells, such as temperature, material properties, weather conditions, solar irradiance and more. A similar type of “photoelectrolytic cell” (photoelectrochemical cell), can refer to devices

• using light to excite electrons that can further be transported by a semiconductor which delivers the energy (like that explored by Edmond Becquerel and implemented in modern dye-sensitized solar cells)
• using light to split water directly into hydrogen and oxygen which can further be used in power generation

In contrast to outputting power directly, a solar thermal collector absorbs sunlight, to produce either

• direct heat as a “solar thermal module” or “solar hot water panel”
• indirect heat to be used to spin turbines in electrical power generation.

Arrays of solar cells are used to make solar modules that generate a usable amount of direct current (DC) from sunlight. Strings of solar modules create a solar array to generate solar power using solar energy, many times using an inverter to convert the solar power to alternating current (AC). Electric vehicles that operate off of solar energy or sunlight are commonly referred to as solar cars.

These vehicles use solar panels to convert absorbed light into electrical energy to be used by electric motors, with any excess energy stored in batteries. Batteries in solar-powered vehicles differ from starting batteries in standard ICE cars because they are fashioned to impart power towards electrical components of the vehicle for a long durations.

The first instance of photovoltaic cells within vehicular applications was around midway through the second half of the 1900s. In an effort to increase publicity and awareness in solar powered transportation Hans Tholstrup decided to set up the first edition of the World Solar Challenge in 1987. It was a 3000 km race across the Australian outback where competitors from industry research groups and top universities around the globe were invited to compete. 

General Motors ended up winning the event by a significant margin with their Sunraycer vehicle that achieved speeds of over 40 mph. Contrary to popular belief, solar powered cars are one of the oldest alternative energy vehicles. Multiple solar cells in an integrated group, all oriented in one plane, constitute a solar photovoltaic panel or module. Photovoltaic modules often have a sheet of glass on the sun-facing side, allowing light to pass while protecting the semiconductor wafers.

Solar cells connected in series creates an additive higher voltage, while connecting in parallel yields an additive higher current. Parallel cells without bypass or shunt diodes that experience shade can shut down the weaker (less illuminated) parallel string (each string a number of series connected cells) causing substantial power loss and possible damage because of the reverse bias applied to the shaded cells by their illuminated partners.

Solar modules can be interconnected to create an array with a desired peak DC voltage and loading current capacity. This functionality can also be accomplished with various other solar devices that do more than just create the desired voltages and currents, such as with MPPTs (maximum power point trackers) or module level power electronic (MLPE) units: microinverters or DC-DC optimizers.

Multiple solar cells assembled together in a single plane form a solar photovoltaic (PV) panel or module. These modules typically feature a glass sheet on the sun-facing side, which allows sunlight to pass through while safeguarding the semiconductor wafers from environmental factors. Connecting solar cells in series increases the voltage output, whereas parallel connections enhance the current output.

Solar modules are often equipped with bypass diodes that isolate shaded cells, preventing them from affecting the performance of the entire string. These diodes allow the current to bypass the shaded or underperforming cells, thereby minimizing power loss and reducing the risk of damage. Solar cells were first used in a prominent application when they were proposed and flown on the Vanguard satellite in 1958, as an alternative power source to the primary battery power source.

By adding cells to the outside of the body, the mission time could be extended with no major changes to the spacecraft or its power systems. In 1959 the United States launched Explorer 6, featuring large wing-shaped solar arrays, which became a common feature in satellites. These arrays consisted of 9600 Hoffman solar cells.

By the 1960s, solar cells were (and still are) the main power source for most Earth orbiting satellites and a number of probes into the Solar System, since they offered the best power-to-weight ratio. The success of the space solar power market drove the development of higher efficiencies in solar cells, due to limited other power options and the desire for the best possible cells, up until the National Science Foundation “Research Applied to National Needs” program began to push development of solar cells for terrestrial applications.

 

Stacking solar cells could deliver cheaper power  22:33 Tue, 20 Jan