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Photovoltaic Refers to an electric voltage caused by light. Solar electricity is a method of turning sunlight into electrical energy. This is achieved through the use of solar cells or solar panels to power home ho me appliances such as TV’s, radios, and any other appliances commonly used. There are two types of electrical currents: A and !. A is alternating current, the standard electrical current in the ".S., in which the flow of electrons is reversed #$% times&second' i.e. (% cycles per second. ! is direct current, which is the type of current supplied by batteries. This is the electrical current that cars use and solar electric panels produce )#*. )edit edit** Components of Solar Panel system V mo modu dule le -so -sola larr pane panel l'' tran transf sfor orms ms lig light ht ene energ rgy y int into o elec electr tric ical al ene energ rgy y and and mai mainl nly y consists of cells made mainly of silicon. Voltage ltage Regul Regulato atorr -cha -charg rgee cont control rolle ler' r' regula regulate tess the the volta voltage ge comi coming ng from from the solar solar panel to the battery batter y by /eeping it from overcharging. overch arging. 0att 0atter ery' y' 0att 0atter erie iess sto store re the the ene energ rgy y pro produ duce ced d by the the pane panell for for use use at at nig night ht or or day dayss when the sun is not available. 1n photovoltaic systems deep cycle batteries are commonly used because the depth of discharge is 2% percent or more before being charged bac/ up. Shallow cycle is the opposite where the battery is discharged only a few percent before being charged bac/ up. 1nve 1nvert rter er'T 'Thi hiss conv conver erts ts the the ! ! cur curre rent nt pro produ duce ced d by the the sol solar ar pan panel el int into o A A curr curren ent, t, so so you can power household appliances. A disc discon onne nect ct'' All Allow owss you you to to man manua uall lly y shu shutt off off the the pow power er goi going ng int into o you yourr hou house seho hold ld appliances. owe owerr 3ut 3utle let' t' Th This is is an outl outlet et so you you can can plug plug in your your TV, TV, radi radio o or or any any othe otherr household appliance you want to power with a photovoltaic system. )$*
)edit edit** Interpretive display 4abeling your system parts can be useful in the setup of the system as well as if you encounter any problems and need to locate a specific part. 5ot only will it ma/e it easy to wor/ with your system, you can also use this display as an educational tool for those who are interested in photovoltaic systems but don’t /now much to start with. Aesthetics' 1f you are placing $% panels on the side of your house or office building you don’t want huge panels that stic/ out li/e a soar thumb. 0eauty is something that the consumer wants when loo/ing into products to buy. 1ntegrating aesthetics into the designing and building of your system will provide a beautiful system that advertises to those who may be interested in purchasing a system of their own. 6a/ing your solar system as simple as possible provides much easier use for everyone who wor/s on it and&or plays with the system. )7* )edit edit** Wiring 6ost wiring associated with V installation is covered under the 5ational 8lectric ode-58. This code covers 9ust about any V installation, on'grid or off'grid.1t specifically deals with any V system that produces power and is accessible to the untrained person. The /ey component is labeling. The 58 suggests that euipment be identified, listed, listed , labeled, or tested by an approved ap proved testing laboratory. labor atory. erhaps the most important aspect is the color'coding of the wiring, in particular the grounded conductor, which should be white .Article (;% of the 58, added in #;<=, specifically
addresses safety standards for the installation of V systems. )=*
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)edit* Solar Path Finding and Shading The sun delivers #%%% watts per suare meter at noon on a clear day at sea level. This is called >full sun?. 6any variables can affect that amount: dust, water vapor, air pollution, seasonal variables, and temperature. Shading, the reduction of full sun due to trees and other structures, reduces the full'sun amount. 8ven a small amount of shading can affect module output. The panels will have the ma@imum output if they are positioned perpendicular to the sun as much as possible. )2* )edit* Maintenance V modules reuire little to no maintenance and essentially, because they have no moving parts, 9ust need to be cleaned. owever, chec/ing the various electrical components either annually or semi'annually is encouraged. )edit* Maintenance steps "sing a voltmeter to measure and record the readings of an array current, battery voltage, load current and any 48!’s or system status indicators. Recording it on a maintenance wor/sheet allows for some historical data. 6easure the following with a portable electric meter: array voltage, battery voltage, current flowing from the array to the batteries hec/ charge controller to ma/e sure it is appropriate for the measured battery voltage and is installed in a dry, clean and ventilated area "se an ohmmeter to chec/ the continuity of the euipment grounding system and that the disconnect switches actually cut'off the power. Visually inspect all wiring. lean battery top and chec/ the electrolyte level of every cell in the battery. Tighten caps by hand, repair or tighten bad connections. 6a/e sure battery bo@ is loc/ed but vented. Bive eualiCe charges -if necessary but only on series stringsD hec/ arrays for any damage and replace any mounting components. Re'verify any shading problems for trees that have grown, buildings that have been built, etc. Repair damaged components in 9unction bo@es, conduit and conduit connectors. 6easure open circuit voltage and current hec/ all loads hec/ inverters Feep maintenance record sheet )(*
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)edit* Testing of components Test system meters'Test on a device where you /now the voltage and verify it is wor/ing and correct Array&panel voltage'"se a ! voltmeter&meter to measure the voltage&erage-in full sun in an array&panel and record 0attery voltage'carefully measure the voltage of the battery before and after connecting and record hec/ status indicators on charge controller and inverter if available hec/ to ma/e sure all systems that need to be grounded have their grounding wires connected
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Verify disconnected components that are disconnected by switches AR8 disconnected by using voltmeter hec/ all wiring to see if any is live by testing voltage and&or current at all points before and after a component 6a/e sure power is off on the charge controller, measure voltage&erage then turn on and re'test and record hec/ all terminals and wires for loose, bro/en, corroded or burnt connections or components 6a/e sure charge controller is clean Gire up the system under full sun and re'test each point and component Turn on the blenderD )E*
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)edit* Off-grid versus on-grid There are two main benefits to a grid'ties system versus off'grid. The grid'ties system can sell e@cess power production bac/ to the grid when producing more and can balance its use by drawing power when the sun is not shining. 3ne main difference is that there are more regulations when tied to the grid. )<* )edit* References H Starr, Bary -#;The Solar 8lectric 0oo/' ow to save III Through lean Solar ower: A ractical guide. 1ntegral ublishing in association with Solar 8lectric, Rohnert ar/, alifornia, #$'$; H Roberts, Simon -#;;#. >Solar 8lectricity: A ractical Buide to !esigning and 1nstalling Small hotovoltaic Systems. rentice all 1nternational -"F ltd, "niversity press, ambridge, Breat 0ritain, 7E'#=# H repared by Solar !esign Associates, arvard, 6assachusetts, and the 5ational Renewable 8nergy 4aboratory, Bolden, olorado, for the ".S. !epartment of 8nergy. >hotovoltaics in the 0uilt 8nvironment: A design guide for Architects and 8ngineers -#;;E ".S. Bov. !ocument, ;2'$%E H ratt, !ouglas and Schaeffer, John -#;;;. KSolar 4iving Source0oo/ The omplete Buide to Renewable 8nergy Technologies L Sustainable 4iving. helsea Breen ublishing ompany, Mhite River Junction, Vermont =E;'=<# H ratt, !ouglas and Schaeffer, John -#;;;. KSolar 4iving Source0oo/ The omplete Buide to Renewable 8nergy Technologies L Sustainable 4iving. helsea Breen ublishing ompany, Mhite River Junction, Vermont 2='2E H 6aintenance and operation of stand'alone hotovoltaic systems -#;;#. Sandia 5ational 4aboratories, Albuuerue, 5ew 6e@ico