SOLAR TIP

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We also carry Matrix, B.P., G.E., Sharp, Sanyo, Uni-Solar, Mitsubishi, Photon, Suntech, ALPS Solar Photovoltaic Panels

SOLAR PHOTOVOLTAIC SYSTEM SIZING

DISCLAIMER

THESE SYSTEMS CAN PRODUCE LETHAL VOLTAGES AND CURRENTS.

We assume (NONE) NO liability for improperly designed or installed Solar Photovoltaic Power Systems. These Solar Photovoltaic Power Cells produce D.C. Voltage and Current. They can be designed and installed by anyone, but you need a understanding of D.C. and A.C. Voltage - Current, a in-depth knowledge of the National Electric Code. These Solar Photovoltaic Systems CAN NOT back feed into the Electric Power Lines (Most Inverters will not let power back feed into the grid). Contact your Local Electrical Inspector, for proper installation requirements or a Electrical Contractor Authorized to Install Solar Photovoltaic Systems.

Average electrical usage of many common appliances

POWER CONSUMPTION CHART - ESTIMATED RATING
AC APPLIANCES WATTS DC APPLIANCES WATTS

Blender                               350                            Blender                             80
Coffee Maker                   1200                            Ceiling Fan                       25
Dishwasher                       1200                             Fan                                    15
Toaster                             1100                             Light Fluor.                          8-40
Microwave                         600-1000                   Radio/Tape                       35
Washing Machine               450                             Refrigerator                      65
Vacuum                            1250                              Television                         60
Iron                                   1000                             Submersible, Pump         150-1200
Computer                            250
Evap Cooler                       240
TV                                      150
Freezer                                450
Hair Dryer                           500-1500
Lights Fluor.                             8-40
Lights Incand.                         40-150
Power Drill                          240
Radio                                      10
Refrigerator                         350
Stereo                                 40-100

SIZING A PV SYSTEM

12 VOLT DC LIGHTS AND APPLIANCES

Fluorescent lights        2ea      20 watts     5 hrs per day     200 watts per day
Microwave Oven           1ea     800 watts   1/2 hr per day     400 watts per day
13"TV VCR Combo      1ea     100 watts    2 hr per day       200 watts per day
       TOTAL DC USAGE PER DAY IN WATT HOURS           800 watts per day

120 VOLT AC LIGHTS AND APPLIANCES

Hair Dryer                        1ea    1200 watts   10 min                200 watts per day
Stereo Tape                     1ea        80 watts   2 hrs per day   160 watts per day
Fluorescent Light           2ea        40 watts   3 hrs per day    240 watts per day
       TOTAL AC USAGE PER DAY IN WATTS HOURS          600 watts per day

Adjusting the loads for system efficiency and operational losses

Multiply the DC loads by 1.3 to adjust - 800 x 1.3 = 1040 watt hours per day

Multiply the AC loads by 1.4 to adjust - 600 x 1.4 = 840 watt hours per day

The AC adjustment is more to account for inverter efficiency

Adding the DC and AC adjusted loads together gives a total of 1880 watt hours per day

MODULE SIZING

The next thing to do is pick a module. Pick a 100 watt module. Look at

the chart below and get the average hours per day of peak production. Let's pick

Columbus, Ohio USA with a production number of 4 (4.15). Multiply 4 times the module

rating.100 x 4 = 400 watt hours per day per 100 watt module. Divide the module

production into the adjusted load 1880 / 400 = 4.7 - you would need 5 - 100 watt modules

for this load in this

each so you will need a charge regulator of at least 30 amps. 5 (modules) x 6 (amps) = 30

- Get a larger one if you have any plans for future expansion.

BATTERY SIZING

Batteries are rated in amp hour capacity. Pick a 220 amp hour battery. Since

it is 220 amp hours (AH) at 6 volts (V) it has a total capacity of 1320 watts (220 AH x 6V).

You must adjust the battery capacity for efficiency and depth of discharge and we use

an adjustment of 70%. Multiply the capacity 1320 x .7 for a total adjusted capacity of 924

watts of usable storage per battery. Since the total adjusted load is 1880 watt hours a

day, you will need two batteries for each day of storage. You want 5 days of storage so

you will require 10 batteries for this system.

INVERTER SIZING

Inverters are sized to the largest AC load you will use at one time. If you plan to use all of

the AC lights and appliances at one time and have enough capacity to run a power tool

you will need an inverter of at least 1000 watts. Since charge controls and inverters are

not modular, like modules and batteries are, it is best to get a larger one than needed if

you have any thought of expanding your system at a later date.

Average Hours of Sun Light
Sun Hours Per Day - National
S=Summer-W=Winter-Yr=Year Round

AL. Montgomery S-4.69 W-3.37 Yr-4.23
OH. Columbus     S-5.26 W-2.66 Yr-4.15
CA. Los Angles   S-6.14 W-5.03 Yr-5.62
FL. Miami             S-6.26 W-5.05 Yr-5.62
ME. Portland        S-5.20 W-3.56 Yr-4.51
SD. Rapid City     S-5.91 W-4.56 Yr-5.23
TX. Midland          S-6.33 W-5.23 Yr-5.83
WA. Seattle          S-4.83 W-1.60 Yr-3.57

SYSTEM SIZING CALCULATION
BY OUR
"SOLAR MANUFACTURER OUT WEST"