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# Solar Technology Math

SOLAR panels are made up of silicon cells. When sunlight strikes the silicon, a flow of electricity results within each cell. The electricity, measured in amperes (or amps), can theoretically be used to run appliances directly. But it is more efficient to collect it in deep-cycle storage batteries. You can estimate the number of solar panels needed for your recreational use by determining the average power consumption per hour (in amperes) for the appliances you wish to run. You will also need to estimate approximately how long you expect to run each appliance.

Here are some ratings of popular 12-volt appliances:

Appliance Amps Used Per Hour

15-to-20 watt flourescent light 1.0 12-inch black-and-white TV 1.5 9-inch color TV 4.0 tape recorder .5 refrigerator 5.0 8-inch fan 2.0 blender 8.0

Use this list to solve the following problem:

Question: You plan to camp out using panels that generate 3 amps per hour. In your locale, these panels will receive four hours of direct sunlight per day. If you run the tape recorder two hours a day, the light six hours, the black-and-white TV two hours, and the blender 15 minutes, how many panels do you need?

Solution: You can set up your problem in this way:

Item Load Consumption x Hours Used = Amps

Amps/Hour Per Day Per Day

tape recorder .5 x 2.0 = 1.0 15-watt light 1.0 x 6.0 = 6.0 TV (B&amp;W) 1.5 x 2.0 = 3.0 blender 8.0 x 0.25 = 2.0

Total = 12.0 Amps

When you know the total amps you will use per day - in this case 12 - divide that figure by the number of amps generated by one panel in your location. For this problem, you were camping in an area with four hours of sunlight, so your panel that generated 3 amps per hour gave a total of 12 amps per day. Thus, the 12 amps drawn per day for all appliances divided by the 12 amps generated per panel = 1 panel.