HOW MUCH SOLAR DO I NEED?

With the advancements in technology, specifically within the solar industry, solar panels have become a lot more accessible and an affordable energy source. Before buying and setting up your solar power system, that common question always comes to mind: “How much solar do I need?” Ask anyone familiar with solar and they’ll all tell you the same thing: “It’s always better to slightly overestimate the amount of solar energy you need rather than underestimate when setting up your system.”

Whether you want to use solar panels on your cabin, boat, van, or RV, you’ll first need to determine how much power you consume based on the appliances and devices you use, and the total length of time you use each one every day.

All electrical appliances and devices should have a label displaying its power consumption in either amps or watts. If the number is listed in amps, you will need to multiply the amps by the voltage to get the wattage. Then, multiply the power consumption (in watts) by usage time (in hours) to get the watt-hours. For instance, a tower fan with a power consumption of 70 watts is used for about 5 hours per day, which means you would need about 350 watt-hours per day for this appliance. Once you calculate the watt-hours for all your appliances and devices individually, you would then add those numbers to get the total watt-hours consumed per day.

The next step is to determine how much power you can get from a solar panel. You’ll need to know the average year sun hours per day and the power rating of your solar panel. Additional factors to consider are the location, season, and even climate to get more reliable data. By doing a quick search online for the average year sun hours per day based on your location, you can easily calculate the power your panel will produce. For example, if you are in Riverside, California, your year average sun hours per day would be 5.87 hours. If you want to know the power you can get from a 100-watt solar panel per day, you will need to multiply 100 watts by 5.87 hours. The result is 587 watt-hours per day for a 100-watt solar panel.

The last step is to determine how many solar panels you need. Let’s say you’ve calculated a usage of about 1500 watt-hours per day and want to purchase 100-watt solar panels. You would then take the 1500 watt-hours and divide it by 587 watt-hours to get a result of 2.56 (round up to 3). Now you know that you’ll need a total of 3x 100-watt solar panels to support your daily power consumption.