A solar battery is a rechargeable battery that integrates a solar cell with battery power storage.
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Solar battery (Typ II) can also refer to rechargeable batteries which have been developed specifically for use in photovoltaic systems. They are used especially in stand-alone systems for storage of energy produced by solar panels and batteries as a buffer when major consumer operation. The term is also commonly used for built-in solar power applications batteries, even if they are not specified for it.
History
The first solar battery was developed in 2014 by researchers at Ohio State University. The researchers used a dye-sensitized solar cell using ruthenium that stores the power that it uses air to decompose and re-form lithium peroxide. It used three electrodes rather than the typical four. It featured a lithium plate base, two layers of electrode separated by a thin sheet of porous carbon and a titanium gauze mesh that played host to a dye-sensitive photoelectrode. Porous materials allowed the battery's ions to oxidize into lithium peroxide, which chemically decomposes into lithium ions and stored as lithium metal. The device used conventional liquid electrolyte consisting of part salt and part solvent (perchlorate mixed with organic solvent dimethyl sulfoxide.
In 2015 the same team announced modifications to their design such that compared with traditional lithium iodine batteries, energy savings reached 20 percent. The new design no longer needed air to pass through it in order to function. Water was the solvent and lithium iodide was the salt. The result was a water-based electrolyte and a prototype now classed as an aqueous flow battery. The device was topped with a solid solar panel in a single solid sheet. Over 25 charge/discharge cycles, the battery released around 3.3 volts. While typical batteries charged with 3.6 volts and discharge at 3.3 volts, the solar flow battery only needed 2.9 volts to charge with the solar panel making up almost 20 percent of the difference
Another team wired four perovskite solar cells in series to enhance the voltage and photo-charge lithium batteries with 7.8% efficiency. Perovskite solar cells have active materials with a crystalline structure identical to the mineral perovskite. Perovskite cells convert a broader spectrum of sunlight into electricity than conventional silicon-based cells.
Used Batteries (Typ II)
The most commonly used for solar batteries battery type was in the past, the lead-acid battery. For its use of low price per storable energy quantity, the achievable maintenance, the low self-discharge and the relatively high efficiency of about 80% spoke. The losses in lead-acid batteries can be explained in part by the outgassing of hydrogen-oxygen during charging. With maintenance-free lead-acid batteries the gas emissions are reduced. Solar-lead batteries vary in their internal mechanical structure of the other lead-acid batteries, they are optimized for a particularly long service life, cycle stability and behavior at low discharge. Typical are numbers of cycles of 1200 (with a depth of discharge of about 80%) to a residual capacity of 80%, since then a battery is considered defective from. Maintenance-free lead-acid batteries have the advantage that there are no or only forms a minimum stratification she sure but allow only a much smaller number of cycles from 400 to 600. An additional circulation of acid prevents completely stratification and the lead-acid batteries. This is especially important in stationary operation.
Some truck batteries are also known. Used which are batteries that usually come as a traction battery for forklifts used. It is yet to lead-acid batteries, but with 1,500 charge cycles and favorable price-performance ratio.
Lithium-ion batteries are also used recently as a solar battery, which is due to sharp fall in prices of lithium-ion batteries (see battery prices). In addition, lithium ion batteries have some very high cycle stability of more than 10,000 charge and discharge cycles and a long service life of up to 20 years. in particular, lithium iron phosphate batteries are used which, and by a high cycle stability, high security small price excel and come as traction batteries for use.
Partly also used batteries are used, which no longer have enough capacity for other applications for example pedelec or electric cars, as solar battery, but still sufficient.
Customers receive money for providing their storage.has a market overview of current storage systems available, the PV magazine and C.A.R.M.E.N. e.V. respectively created.
In Germany, solar batteries with lithium-ion batteries with a capacity of 4.4 kWh from 5,500 euros available (as of 1/2016). In Austria, solar batteries with lithium-ion batteries with a capacity of 4.5 kWh from 4,500 euros or 7 kWh from 8,000 euros available (as of 1/2016). Thus one has self-produced electricity for the night. Despite additional costs of operation of photovoltaic is therefore more economical.
The Tesla Powerwall offered in the USA by SolarCity incl. Installation with 10 kWh for $ 7,140.