Is 1500 watts enough?

[Saggys]

For those that are actually off grid is 1500 watts enough of an inverter? I have a temporary 1500 watt system in place at our hunting shack and it seems to be working fine. It is very low end compared to what I would replace it with. I would be running LED lighting, flat screen TV, radio/cd on occasion along with microwave and coffee maker. I am not using anything but lighting and TV on my temp. system. Everything that can be on propane, except lighting, will be. I will also have a 2.5kw generator that can provide battery charging and additional load powering if needed. I know this system is small but it keeps it cost effective as doing this properly costs more than I originally thought. Have you seen what they get for pole mount racks? I would probably sell some of my larger equipment to fund batteries and all the other things that go along with this (never ending, disconnects, cables, etc.). I would rather have a properly matched system than one that is out of balance even if it meant having less power available. So, can it work? I think it can!

[Naptown]

Go to the stickie to the off grid battery design and plug in the loads and all that may run at the same time into the spreadsheet there.
that's a quick way to find out and finish off the rest of the system components so it works properly. that is not a final design tool but will get you close in system size.

[Sunking]

I think if you are just asking about an inverter right?

The trouble you can get into is not having the right size battery and battery type matched to run a given inverter. 99% of people have way too large of an inverter for a given battery.

For example we see a lot of people have say a pair of Trojan T-105 batteries which are 6 volt 225 AH batteries connected in series to make 12 volt 225 AH battery with a 1000 or more watt inverter. As long as you do not push the inverter to full power life is good. But then you get the question why does the inverter trip off-line when I use it on say my Microwave Oven when the oven is only say 800 watts. Well the problem is that paticular battery can only supply about a C/4 discharge rate before you start running into significant voltage sag. So C/4 = 225/4 = 56 amps and convert that to watts on a 12 volt system and the largest load that battery can supply is 675 watts. Now they are trying to push 1000 watts or more. Will not work, or least not for very long.

So yes a 1500 watt inverter should be large enough as long as you remember not to try to run the microwave and coffee pot at the same time and have a large enough battery to operate the inverter at full power. Depending on battery type and voltage but assuming 12 volt which is not a high enough voltage for a 1500 watt inverter you are looking at 200 to 1000 AH battery.

[Saggys]

You are correct Sunking, I am asking about the inverter alone. It would be a 24 volt inverter/charger and I was thinking four six volt Trojan T105RE's to power it with. That should be good for 1350 watts at C/4. This set up should keep costs down especially with batteries. To do a set up like this NEC compliant is more difficult than a utility home service. So your sticky "You want to go green" is very true.

[Naptown]

Those are a FLA battery and not designed for that high a discharge rate. for that you would need something like a Concorde Sunsaver AGM battery. or a much larger battery bank. Peukerts law will bite you at that high a discharge rate on that type battery.

[Saggys]

Naptown you are correct, even at C/8 they should be able to deliver 675 watts. I think they could hopefully make a pot of coffee or run a microwave, as this would not be a continous load. I have made a pot of coffee with my temporary system, but have not tried a microwave.

[Sunking]

For a short term quick load no problem. T-105's are hybrid golf cart batteries.