Integrated Power Systems > Off-Grid Solar System Sizing

For off-grid solar system sizing, these figures are approximate representations. The actual power consumption of your appliance may vary substantially from these figures depending on its age. Where a range of numbers are given, the lower figure often denotes a technologically newer and more efficient model. Check the power tags, or better yet, measure the amperage draw with a clamp – on ammeter or plug in a Kill- a – Watt measuring device.

Power Consumption Table

off-grid solar system sizing
Multiply the hours used on the average day by the wattage listed. This will give you the watt hours consumed per day. Remember that some items, such as garage door openers, are used for only a fraction of an hour or minutes per day. A 300 watt item used for 5 minutes per day will only consume 25 watt hours per day. We recommend for “off-grid” living, the use of propane to operate ranges and hot water heaters as well as changing your lighting to the newer energy efficient compact fluorescent or LED bulbs.

Load evaluation form

Now that you have figured out the corrected watt – hrs per day, you can send us this page or see the GUIDE on how to use this data.


The load correction factor is required as batteries are not 100% efficient and other losses occur in a system. We increase the load value by 25% to compensate for these losses.