If you’re planning to use solar power off the grid (meaning you won’t be connected to any city-run power sources), you must appropriately size your system. Failure to correctly calculate your system’s size can result in you running out of power frequently or overpaying for the equipment you never really needed. Read this article to get a basic idea of how to size your off-grid solar system correctly. But if you want to make sure your power needs are met, have a professional size it for you.

Off-Grid Solar Panel

Calculating Your Energy Usage

The first step in getting a solar system that meets your energy usage is knowing how much energy you use. If you were connected to a power grid, checking your electric bill would be a fast and easy way to do this. But if you’re not on the grid, you’ll have to calculate your usage by hand. Check every appliance and device you plan to use in your home for a sticker that indicates its power requirement in watts. Record these, then map out which devices are likely to be on at the same time to determine your peak load. Now, estimate how many hours each device will be on each day. The total will be your energy usage every day. Both the peak load and total load are essential calculations for sizing.


Buying Solar Panels

Your calculation for total usage will help you choose your solar panels and purchase the correct number. You should easily be able to see how much electricity a panel is capable of generating. Purchase the right number to equal your total usage.


Selecting a Solar Inverter

There are two primary types of inverters: modified sine wave and true sine wave inverters. Modified sine wave inverters are cheaper but may cause some operation issues with modern devices like stereo systems and computers. Actual sine waves cost more but don’t have the problems mentioned above and are more efficient.

You’ll also need to ensure that the solar inverter you choose is rated to provide for your peak load calculation mentioned above.


Designing a Battery Bank

Battery banks are essential for off-grid solar systems, as they’ll keep your home running when the sun goes down. You’ll want to ensure you have enough battery storage to power your home throughout the day, too, for those days when it’s cloudy. Calculate the total watt-hours (Wh) you can get from a battery by multiplying its voltage and amp-hours (Ah). It would help if you then subtracted any battery percentage that cannot be discharged; all batteries will have a maximum depth of discharge (DOD) rating.

If you have a 12V with 50Ah capacity, that battery would have a maximum capacity of 600Wh. If it has a maximum DOD of 50%, its maximum discharge is 300Wh or 3 hours of run time. Use these calculations to find the most efficient batteries and the correct number of batteries for your home.

If you’re looking for components for your off-grid system, like the Sol-Ark inverter, lithium batteries, solar panels, and more, check out our catalog of wholesale solar equipment. And if you need assistance with designing your system, contact The PowerStore, Inc., today!