Miro Solar Panel Guide 2012

8/2/2019 Miro Solar Panel Guide 2012

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POWERFULCOMMUNICATIONSOLUTIONS

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ALL US NOW ON ... 086 J23MIRO (6476) OR EMAIL [email protected]'WIRELESS "NETWORKING QVolP QVIDEO WWW.MIRO.CO.ZA

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What is the best voltage to use?The best Voltage to use is somewhat dependent on the type of equipment that you plan to use & thecommon voltages that they share. Within Mira's existing product range, the voltages vary between5V, 9V, 12V, 18V, 24V, 48V & 55Volts. Fortunately the large majority of our equipment can run on themore common 12V, 24V & 48Volt inputs. This can be easily matched by using solar panels in seriesor parallel configurations. Please refer to the simple wiring diagrams below which illustrate some ofthe options that are available to you.Using a higher voltage, say 24148Volts is often more efficient than a 12Volt system. As a 12 Voltsystem will need to run at higher Amperage which in turn requires a thicker cable to carry it. If youuse a narrow gauge wire you will incur loss through high resistance. Conversely running a highervoltage allows you to reduce the wire gauge (thickness) that is needed.Miro carries a range of DCto DC step-up & step-down converters. These converters can increase ordecrease the Voltage to a level that is supported by your hardware. Any conversion of power is bestto be avoided. Energy is always lost in the conversion process (20-30%) which reduces the efficiencyof your system and increases the overall cost & the complexity of the installation. It is thereforerecommended that you try to use one Voltage that is common between the various types ofhardware.

Parallel = Voltage remains the same but the Amps are doubled:

1

12 Volt10Amp--- -


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Series = Voltage is doubled but the Amps remain the same:

1

24 VoltSAmp

Series Pairs = Voltage & Amps are doubled:

+

24Volt10Amp----


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Basic SetupSOLAR CHARGEREGULATOR

- . . . . . .. . . +- ' . ' . . . ,+ -- . ' . ' t t ' .. - . - . - - . - - . ' . -. . - -. . - . . . . .. . . '. . "- . - . t - . ' . - - . - t- --. - t ,,- . ' ,-. . - . - -+ - -t- -f- . . .- t--t- -t -t- -t- - . - -t- - . - BATTERY- . " ,. ' . ' . ' . '....'t- -t- ,t -t- ,+ -SOLAR PANEL

How to establish your power requirements:1. Make a comprehensive list of all of the electronic equipment that you plan to run off the solarsystem.2. Find out how many Watts each component uses. This information is often available from the

manufacturer's website or on the data sheet of the specific product. Should you not know howmany Watts your device uses, you can use a standard handheld multi meter to calculate theactual usage. The multimeter must be set to "AMPs" or "DC Current" & with the probes in thecorrect sockets. Additionally the multimeter must be part of the circuit that is powering yourdevice. Turn on your device & you should see a reading of a few milliamps to a few Amps. Tocalculate the Watts simply multiply the Volts by the now known Amps.

Example: Watts;::::; Volts x Amps55Volts x 0.45Amps;::::;25Watts3. Add up the total amount of Watts used by all the equipment .


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How to correctly size your solar system:1. Find out how much energy all of your equipment will use in one full day of operation. This is done

by multiplying the total power consumption by twenty-four hours.Example: Total Watts x 24 Hours = Watt Hours

S9Watts x 24Hours = 1416Watt Hours2. Add 30% to this total for inherent inefficiencies. This will compensate for the potential loss of

energy due to resistance in the wiring + connections, misalignment of the solar panels & theenergy lost during the charging process. It's important to note that batteries do not store 100%of the energy they are given. On average they use 20-30% extra depending on their state ofcharge. If you use 10 Amp Hours from your battery you will need 13 Amp Hours of energy toreplace it.

Example: Watt Hours x 130%= Watt Hours1416 Wh x 130%;:: 1841Wh

3. In South Africa, on average, solar panels will receive 5 hours a day of good sunlight (peak hours).Your solar system needs to recharge its batteries during this narrow five hour window. It'simportant to note that different geographical locations receive different quantities of averagepeak sun hours per day.


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Divide your total amount of watt hours by five hours. The value you will receive is your rough guideas to the capacity of the panels that you will require.Example: Watt Hours + 5 Hours = Watts

1841Wh + 5Hours.: 368WYou can match this requirement by using various combinations of solar panel(s). Somecombinations may be more cost-effective & easier to install than others. The example below showsthe available options you that have to meet the 368 Watt power requirement.

REQUIRE SOLAR :PANEl QUANTITY" TOTAL' i ' i - - . . ._ ~ . . .~ " " ( 1 ! SIZE ~4'1 ~


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REGULATOR AMPS VOLTAGE STATUS,+~ODEL~~4'f' , ~ . . . . . - r : t ~ . .4 ' ~ . . .~ ...#:'""_ . - - - . ,-~IN-REG-05 5 12/24 XIN-REG-10 10 12/24 XIN-REG-15 15 12/24 ./IN-REG-20 20 12/24 ./

How to choose the right batteries for your needs:Your batteries will need to provide your equipment with electricity during the periods where there isno sunlight. The batteries can be thought of as the fuel tanks of your solar system. If your batteriesare sufficiently large enough they should be able to run your equipment for a number of days withoutany sunlight at all & not be discharged by more than 50%. To calculate how many batteries you'llneed, take the daily power usage & multiply it by the number of days that you want your system torun, and then multiply again by 2 (to factor in the 50% discharge limit). Lastly, we divide this value bythe voltage of the battery or batteries to convert it back into Amp Hours (Ah).Example: Daily Watt Hours Usage x 3 Days x 2 7- Battery Voltage:::; Ah

1416Wh x 3 Days x 2 7- 24V:::; 354AhEight 12Volt 100Ah batteries in series pairs would be needed, giving you 400Ah at24Volts.

(See image on next page)


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-1

24 Volt400Ah

Installation Tips:t. For optimum performance face your solar panels North at a 30 degree angle.2. Avoid unnecessary loss of energy by using thick multi-strand copper wire. (Minimum 10

AWG/5.2mm212.5mm)3. Any conversion of power is best to be avoided. Energy is always lost in the conversion process

which reduces the efficiency of your system & increases the overall cost.4. Always use solar regulators (charge controllers) as they prevent the batteries from being

permanently damaged though overcharging or excessive discharge ..5. Use deep cycle batteries as they are designed to be discharged over a long period of time (up

to 50%) & recharged hundreds or thousands of times, unlike conventional automotive batteries.6. Don't over-work your batteries as it greatly reduces their effective lifespan. Standard lead acid

(Pb) batteries can be discharged up to 20% of their capacity & deep cycle batteries as much as50% ..

7. It is recommended that the batteries & charge controller are housed within the same ventedenclosure. Batteries are sensitive to temperature variations, most are rated by the manufacturerbased on an ambient temperature of 25C. Modern solar regulators (charge controllers) usebattery temperature compensation which adjusts the charge rate based on the ambienttemperature. Therefore it's important that both the charge controller & batteries are exposed tothe same thermal environment in order for the battery temperature compensation to workeffectively.

8 .. When connecting multiple batteries in parallel be sure to use the alternate ends (positive &negative) of the bank. This will ensure that all of the batteries receive an even charge ..

9. Don't house your other electronic equipment within the same enclosure as the batteries (exceptfor the charge regulator). The battery vapor given off during the charging process contains

microscopic acid droplets & will quickly corrode your equipment.10. During the installation process, only strip one wire at time to avoid accidentally making contact

between the positive & negative wires which may damage your equipment.11. Never mix batteries or solar panels that have different Voltage ratings.


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Glossary:Amps (A): A measure of the amount of electric charge passing a given point.The amount of air rushing through the balloons opening, the speed at which it exits is VoltsAmp Hour (Ah): A unit of measurement of a battery's electrical storage capacity.CUrrent multiplied by time in hours equals ampere-hours. One amp hour is equal to a current of oneampere flowing for one hour.Parallel Connection: The arrangement multiple batteries made by connecting all positive termi-nals together and all negative terminals together. The voltage of the group remains the same as thevoltage of the individual battery. The capacity is increased in proportion to the number of batteriesadded.Onm's Law: The formula that describes the amount of current flowing through a circuit.Ohm's Law - In a given electrical circuit, the amount of current in amperes (I) is equal to the pressurein volts (V) divided by the resistance, in ohms (R). Ohm's law can be shown by three differentformulas:To find Current I = VIRTo find Voltage V = I x RTo find Resistance R = VIIPV Panels: Photo voltaic (PV) systems use fight from the sun to create electricity. PV panels arecommonly known as solar panels. Two types are commonly available:

Monocrystalline SolarPanels: Are more expensiveto produce but are moreefficient than poly and cancapture more watts per squarefoot of solar cells.

Po/ycrystalline SolarPanels.~Are cheaper toproduce, but are not asefficient as mono. Panels areusually larger for the same wattrating.

Series Connection: The arrangement of batteries configured by connecting the positiveterminal of each successive battery to the negative terminal of the next adjacent battery so that theirvoltages are cumulative. The capacity of the group remains the same as the capacity of theindividual battery. The Voltage is increased in proportion to the number of batteries added.Volts (V): Electric potential difference.Think of it like the air pressure difference between the inside of a balloon & the outside atmosphere.The volume of eir leaving the balloon can be thought of as Amps.Voltag~ Drop: a aecreese in Voltage along a conductor through which currentIS flowing due to resistance.You can compare the conductor to your typical garden hose & the voltage drop as the loss in waterpressure. The farger the hose (thicker wire) the less water pressure (Voltage) is lost. The size ofconductor is only one factor effecting resistance, the type of material & temperature of theconductor also has an effect.Watts (W): Is simply electrical power/strength, Watts = Volts x AmpsExample: 12Watts = 12Vofts x 1AmpExample: 12Watts = 1Volt x 12Amps

.\' Watt Hours (Wh): is a unit of en~rgy equivalent to one watt (1 W) of power... expended for one hour (1 h) of time.Your monthly electricity bill is expressed in kilo-watt hours kWh (How many thousands of watts of

- energy you used over time).

Miro Solar Panel Guide 2012

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