This is the first of a series of 4 videos I made to help people size an off grid emergency solar generator in case of a long term power outage. I go over watt hours and maximum rated wattage loads. I also introduce the Kill A Watt meter.
Add up all of the maximum wattage rating from all of the devices you want to run at the same time and that cause the greatest load. Then, add another 25% to 35%. This should tell you the approximate size inverter you need. If you run something that requires a large amount of wattage when first starting up, you need to consider this in your inverter selection. You also need to know if you are going to run a 12, 24, or 48 volt system when selecting an inverter. Use this information when discussing your needs with the solar supply company.
To get the most life out of your battery bank, many solar supply companies suggest not discharging more than 50%. This may only apply to certain types of batteries. You need to inquire about this. With my AGM batteries, I could discharge more, but they will last longer if I do not. So, I suggest adding up all the watt hours your devices use within a 24 hour period and at least double the watt hours to determine minimum battery bank size.
I am not an electrician so you should fact check me before making any decisions based on anything I suggest. Don’t rely on my suggestions or advice to make important decisions related to your system until fist speaking with an electrician (I did) and solar supply company (I did). This is just a hobby for me…
Here is the form I made for you…
Here is a link for the Kill A Watt meter… http://www.homedepot.com/p/Kill-A-Watt-Electricity-Monitor-P4400/202196386