Off-grid Calculator Solar Array

Welcome to the Alternative Energy Store Calculator. This calculator is designed to help you size a system for off-grid use. Start by filling out the first tab, titled Solar Panels. This tab will calculate how many Solar Panels you need, based upon you load(how much electricity you consume). Once you've completed this tab, move on to the other tabs labeled Charge Controller & Battery Bank.

Solar Panel Array Sizing Determine the size of the solar panel array you will need. Step 1: How many kilowatt-hours (kwh) does your home/location use per month? (This value is usually printed on your electric bill. If you don't have a bill, or don't know your consumption, click on 'load calculator' at the top of this page to go through the steps to determine this value.) kilowatthours per month Step 2: You need to determine the minimum number of sun hrs per day during the winter. Select the State-City Closest to your location (currently only US states are provided) MA-Boston

Minimum sun-hours for the winter times or Manually enter the minimum sunhours for your location. Step 3: The total wattage of Solar Panels that you need is:

This value takes into account losses due to system inefficiencies. Step 4: How many solar panels do you need? That depends on the panel you choose. Select the wattage of the panel your interested in, and see the results below: 125

© 2005 Alternative Energy Store - www.AltEnergyStore.com

| Solar Panels | Charge Controller | Battery Bank | Load Calculator | | Solar Panels | Charge Controller | Battery Bank | Load Calculator | Charge Controller-Used between your solar panel array and your battery bank, charge controllers optimize how your batteries are charged and prevent current from going back through the panels from the batteries during the night time.

Solar Charge Controller Sizing This calculator helps you size the solar charge controller(s) needed for your system. Step 1: (taken from the previous calculation of solar panels) Step 2: Choose the voltage of your battery bank: 12

Step 3: You will need a charge controller(s) that can support at least: Amps

| Solar Panels | Charge Controller | Battery Bank | Load Calculator | | Solar Panels | Charge Controller | Battery Bank | Load Calculator |

Battery Bank Sizing This calculator will help you size the battery bank for your system. Wattage of solar panel array:

Watts

Step 2 How many days of backup power do you want in case of cloudy/rainy days?

Step 3 What is the lowest temperature your battery bank will experience? Degrees Fahrenheit Results

Amp Hrs Select a battery amperage:

Select a battery voltage:

350 8

Amp-Hour capacity of this battery is: Voltage of this battery: Batteries per row (in series)

amp-hrs volts

Number of rows in parallel Total number of these batteries you will need: Total Amp-Hours of this Battery Bank is:

AmpsHours

*All calculations assume only a 50% discharge to your batteries to optimize battery life. © 2005 Alternative Energy Store - www.AltEnergyStore.com | Solar Panels | Charge Controller | Battery Bank | Load Calculator | | Solar Panels | Charge Controller | Battery Bank | Load Calculator | To use this form, simply list all of your appliance that use electricity. These are items like Refrigerator, Range, computer, stereo, lights etc.. For each appliance, enter the number of that appliance that you own (Qty), the power is uses (Watts) and the number of hours a day (Hrs/Day) you use the item. We have a provided a list of common appliance and their power consumption at the bottom of the page.

Load Calculator Use this form if you don't know what your power consumption (kilowatt-hours) is. Name: Date

Appliance* Qty 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Watts (Volts x Amps)

Hrs/Day

Watt Hrs/Day

15 16 17 18 19 20 Total Watt Hrs Per Day: Total Kilowatt Hrs Per Month (30 Days): (write down this value and enter it into Step 1 of solar panel sizing calculator) © 2005 Alternative Energy Store - www.AltEnergyStore.com *Help! I'm not sure of the wattage of my appliances. Select the appliances from this drop down menu. To the right will appear typical wattage values for the appliance you selected. However, for the most accurate information look on your appliance to find its wattage rating (or it amperage rating and then multiply that by its voltage to approximate its wattage). Stereo

Watts

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