PV SYSTEM SIZING

The Virtual Solar Engineer

Use the solar sizing program below to help you estimate your electrical needs. Enter the electrical usage of each device in the Watts column, the number devices in the No. column and the hours used each day in the Hrs/day column. Click here for additional HELP with the program. Click here if you would like more information about the efficiency of lighting and appliances. Note: All of the table entries colored green will be filled in for you by the program after you click the Calculate Total Cost button at the bottom of the tables. Please note that the program automatically adjusts for system loss factors ( it will appear that it is adding up the numbers wrong) - this is built into the program to account for normal system losses associated with all PV systems that have battery storage. The system losses are greater for AC systems (house electricity) than DC systems (car electricity) because of the efficiency in converting the electricity.

Watts of common AC Appliances Blender - 350 watts Coffee Maker - 1200 watts Dishwasher - 1200 watts Evap Cooler small - 240 watts Freezer - 450 watts Hair Dryer - 500 to 1500 watts Iron - 1000 watts Lights, fluorescent - 8 to 40 watts Lights, incandescent - 40 to 150 watts Microwave - 600 to 1000 watts PC Computer and monitor - 250 Power Drill - 240 watts Radio - 10 watts Refrigerator, 14 cu ft. - 350 watts Stereo - 40 to 100 watts Television, 19" color 150 watts Toaster - 1100 watts Vacuum Cleaner, large - 1250 watts VCR - 40 watts Washing Machine - 450 watts

AC Lights and appliances	Watts	No.	Hrs/day	Watt/hrs
Fluorescent lights
Fluorescent lights
Incandescent lights - Not recommended
Incandescent lights - Not recommended
TV
Radio
Stereo
VCR
Microwave
Pump
Vacuum Cleaner
Refrigerator - HELP
Other light, tool or appliance
Other light, tool or appliance
Other light, tool or appliance
Other light, tool or appliance

Total adjusted load

Watts of common DC Appliances Blender - 80 watts Ceiling Fan - 25 watts Fan, 8 inch - 15 watts Lights, fluorescent - 8 to 40 watts Radio, Tape Player - 35 watts Refrigerator, high efficiency 65 watts Television, color 10 inch 60 watts Submersible Pump - 150 to 1200 watts VCR-TV Combo - 100 watts

DC Lights and appliances	Watts	No.	Hrs/day	Watt/hrs
Fluorescent lights
Fluorescent lights
Incandescent lights - Not recommended
Incandescent lights - Not recommended
TV
Radio
Stereo
VCR
Microwave
Pump
Vacuum Cleaner
Refrigerator - HELP
Other light, tool or appliance
Other light, tool or appliance
Other light, tool or appliance
Other light, tool or appliance

Total adjusted load

 Note: All table entries colored green will be filled in for you after you click the calculate button.

Total AC-DC. Watt Hours		COST
Choose Location (click here)
Choose a Module Size	10 20 40 49 75 100
Choose Your System Voltage	12 24 48 HELP	N/A
Total modules (calculate button)
Pick how many days of storage	0 3 4 5 6 7 8 9 10 HELP	N/A
Choose your battery size	6V 220 AH 6V 345 AH
Total batteries (calculate)
Charge control
Pick an Inverter (AC System)	DC-Only 100 200 400 700 1300 1500 2400 3600 4000 HELP

Total Cost - $

You must click the calculate button below to get the total cost or to update the total cost after you make changes. If some odd letters or numbers appear in the total cost window, just hit the calculate button again and it will recalculate correctly.

The Virtual Solar Engineer is designed to give you a good idea of solar electric system costs. Try different panel sizes, loads, system voltages and it will help you to pick a system that costs less. Always remember to click the calculate button after you make changes. The program will also give you a good idea of how efficiency and conservation can save you big bucks. It is not designed to produce results that are as accurate and reliable as those generated by professional engineers or solar dealers that have expertise in designing systems. It is probably faster though!

The above calculations are based upon a minimum system for the usage that you have entered. If you have any thought of future expansion, a minimum system may not be the most advisable. If you would like to have the estimate of system cost evaluated by our staff and give you recommendations about a system to fit your needs, we need the following informaton:

Copyright 2000 AAA Solar Supply Inc. - All rights reserved You may use this program for your own personal use and copy it electronically as you wish. Any and all commercial use, sale or incorporation of this program into any CD, book, other program or web site is specifically prohibited and requires the permission of AAA Solar. If the use is for a nonprofit organization we will almost always give you permission for it's use, but we still require that you ask.

Feedback and suggestions - comments appreciated - Chuck

Last modified when we last modified it