Solar powered flashlights (American English) or solar powered torches (British English) are flashlights powered by solar energy stored in rechargeable batteries. Most of these flashlights use light-emitting diodes lamps [1] [2] since they have lower energy consumption compared to incandescent light bulbs. [3]
Solar powered flashlights vary in features and capabilities. A typical solar flashlight can give useful levels of illumination on objects up to 50 metres away, and beam may be visible for much longer distances. The solar cells used for battery charging have an indefinite life expectancy. A solar powered flashlight may give several hours of light after being charged during the day. [3] These flashlights may be designed to be impact resistant, weatherproof, and to float. [4] [5]
Other models include features such as a solar cell phone charger, [6] an AM/FM radio, or a siren to call for help in an emergency. Some models include a hand crank dynamo for charging at night. [7] An experimental solar flashlight the size of a credit card features a white LED powered by 16 solar cells. [8]
Solar powered lights need not be manually recharged as in the case of conventional battery operated flashlights. [3] Pollution from discarded batteries used in normal flashlights is eliminated. [4] Solar powered flashlights can be used in remote locations where it is impossible to find any source of electricity except for solar power. [4]
A built-in solar cell array in a hand-held product has a very small capacity. The light output and run time of the solar flashlight are limited by the amount of energy that can be absorbed in a day. Flashlights are usually stored indoors or otherwise out of direct sunlight; consumers may find it inconvenient to remember to place the flashlight in full sunlight for several hours before use. Rechargeable cells self-discharge, so unless the flashlight is stored in a sunny location, the light may not function in an emergency. Rechargeable cells have a finite charge/discharge cycle life, and when the cells wear out it may be difficult for the consumer to replace them. Some of these disadvantages can be mitigated by separating the solar cell array from the flashlight, but then the simplicity of automatic charging is lost. [9] [ citation needed ]
Solar powered flashlights have been distributed to countries where there is either no or erratic power supply, helping people feel safer leaving their homes at night, and giving children the opportunity to study after sunset. [10] [11] A dual purpose solar flashlight, which also functions as a lamp has helped families in such countries spend more time together, surgeries to be performed during power outages and people to travel in the dark under a halo of light. [12] [13] [14]
A rechargeable battery, storage battery, or secondary cell, is a type of electrical battery which can be charged, discharged into a load, and recharged many times, as opposed to a disposable or primary battery, which is supplied fully charged and discarded after use. It is composed of one or more electrochemical cells. The term "accumulator" is used as it accumulates and stores energy through a reversible electrochemical reaction. Rechargeable batteries are produced in many different shapes and sizes, ranging from button cells to megawatt systems connected to stabilize an electrical distribution network. Several different combinations of electrode materials and electrolytes are used, including lead–acid, zinc–air, nickel–cadmium (NiCd), nickel–metal hydride (NiMH), lithium-ion (Li-ion), lithium iron phosphate (LiFePO4), and lithium-ion polymer.
A flashlight (US), or torch (CE) is a portable hand-held electric lamp. Formerly, the light source typically was a miniature incandescent light bulb, but these have been displaced by light-emitting diodes (LEDs) since the early 2000s. A typical flashlight consists of the light source mounted in a reflector, a transparent cover to protect the light source and reflector, a battery, and a switch, all enclosed in a case.
Maglite is a brand of flashlight manufactured in the United States by Mag Instrument, Inc. located in Ontario, California, and founded by Anthony Maglica. It was introduced in 1979. Constructed principally of anodized 6061 aluminum, they have a variable-focus beam. Maglites are produced in several colors such as black, silver, blue, red, green, purple, gold, and different finishes. Originally Maglite flashlights used krypton or xenon incandescent bulbs. Current models have LEDs, although the older models are still widely available.
A solar vehicle or solar electric vehicle is an electric vehicle powered completely or significantly by direct solar energy. Usually, photovoltaic (PV) cells contained in solar panels convert the sun's energy directly into electric energy.
A solar-powered watch or light-powered watch is a watch that is powered entirely or partly by a solar cell.
A mechanically powered flashlight is a flashlight that is powered by electricity generated by the muscle power of the user, so it does not need replacement of batteries, or recharging from an electrical source. There are several types which use different operating mechanisms. They use different motions to generate the required power; such as squeezing a handle, winding a crank, or shaking the flashlight itself. These flashlights can also be distinguished by the technique used to store the energy: a spring, a flywheel, a battery or a capacitor.
A battery charger, recharger, or simply charger, is a device that stores energy in a battery by running an electric current through it. The charging protocol depends on the size and type of the battery being charged. Some battery types have high tolerance for overcharging and can be recharged by connection to a constant voltage source or a constant current source, depending on battery type. Simple chargers of this type must be manually disconnected at the end of the charge cycle. Other battery types use a timer to cut off when charging should be complete. Other battery types cannot withstand over-charging, becoming damaged, over heating or even exploding. The charger may have temperature or voltage sensing circuits and a microprocessor controller to safely adjust the charging current and voltage, determine the state of charge, and cut off at the end of charge. Chargers may elevate the output voltage proportionally with current to compensate for impedance in the wires.
Eveready Industries India Ltd. (EIIL) is an Indian company that manufactures and markets batteries and lighting products. The Eveready brand has been present in India since 1905. It also manufactures photogravure plates, castings, carbon electrodes and related products.
A solar car is a solar vehicle for use on public roads or race tracks. Solar vehicles are electric vehicles that use self-contained solar cells to provide full or partial power to the vehicle via sunlight. Solar vehicles typically contain a rechargeable battery to help regulate and store the energy from the solar cells and from regenerative braking. Some solar cars can be plugged into external power sources to supplement the power of sunlight used to charge their battery.
A solar lamp, also known as a solar light or solar lantern, is a lighting system composed of an LED lamp, solar panels, battery, charge controller and there may also be an inverter. The lamp operates on electricity from batteries, charged through the use of solar panel
A solar charger is a charger that employs solar energy to supply electricity to devices or batteries. They are generally portable.
A battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal. When a battery is connected to an external electric load, a redox reaction converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell.
SunCore Corporation is a company that produces light-powered intelligent charging systems to power today's mobile devices for original equipment manufacturers (OEMs), operators and distributors, cofounded in 2004 by The Brimmer Family in Irvine, California.
Solar cell phone chargers use solar panels to charge cell phone batteries. They can be used when no electricity supply is available—either mains or, for example, a vehicle battery—and are sometimes suggested as a way to charge phones without consuming mains electricity, unlike electrical cell phone chargers. Some can also be used as a conventional charger by plugging into an electrical outlet. Some chargers have an internal rechargeable battery which is charged in sunlight and then used to charge a phone; others charge the phone directly.
Solar street lights are raised light sources which are powered by solar panels generally mounted on the lighting structure or integrated into the pole itself. The solar panels charge a rechargeable battery, which powers a fluorescent or LED lamp during the night.
Sun-free photovoltaics is a photovoltaics technology which does not require sunlight to produce electricity. This technique was developed by research team at Massachusetts Institute of Technology. Photovoltaic cells convert light to electricity most efficiently at specific wavelengths. The surface features of Sun-free photovoltaics is engineered such that it converts heat energy into the specific wavelengths. This increases the efficiency of existing thermophotovoltaic (TPV) systems.
Solar traffic lights are signalling devices powered by solar panels positioned at road intersections, pedestrian crossings and other locations to control the flows of traffic. They assign the right of way to road users by the use of lights in standard colors, using a universal color code.
The following outline is provided as an overview of and topical guide to solar energy:
The LuminAID is a solar-rechargeable light that packs flat and inflates to diffuse light like a lantern. LuminAID technology was invented in 2010 by Anna Stork and Andrea Sreshta.
There are many practical applications for solar panels or photovoltaics. From the fields of the agricultural industry as a power source for irrigation to its usage in remote health care facilities to refrigerate medical supplies. Other applications include power generation at various scales and attempts to integrate them into homes and public infrastructure. PV modules are used in photovoltaic systems and include a large variety of electrical devices.
