Small Cabin Electrical Use

[MountainDon]

The last couple of weeks up in the mountains I've had the Kill-A-Watt metering all the used output from the inverter. This has been measuring the lights, TV, small stereo and vacuum, but not the microwave as the microwave won't run off the cheap square wave inverter. No power tools like the circ saw or air compressor either (those ran off the generator), but that does include recharging tool batteries a few times. So the figures will be different later on when the PV system is in full operation with the Outback pure sine wave inverter.

However, I thought it interesting that over a 10 day period the meter totaled up 3.3 KwH; 0.33 KwH per day .  

I know it's going to be a lot more later on, just thought I'd measure the difference.

[Phssthpok]

This is nice to know. I was somewhat concerned about having enough solar in the winter for my plans, but with an 800AH bank and just about 1KW effective array (1.3-ish KW rated) I should be just fine. I doubt I'll have as many loads as what you're running, though I will most likely have a small chest freezer to maintain (which will likely be moot in the winter ).

Still, even if I break .5KWh usage per day, I should have about four days of reserve*(read: snow covered panels) before needing to fire up any generators. Even in cloudy conditions SOME power will be trickling into the bank through the array. If the array only puts out 25% of capacity for the four hour 'solar window' that still gets me a full KWh for the day! Even at a mere 10% output I can ALMOST cover a days usage (at .5kwh/day rate).

Are all your loads (lights, fans, radios, etc.) off the inverter or do you have some direct 12vdc loads as well?

* Cut off point being no more than 25% discharged. 800AH drawn down to 600AH (200 AH consumption) = 75% charge reserve.
200ah @12 vdc = 2400Wh or 2.4 KWh /4 days = .6Kwh/day available...almost twice your listed consumption.

[MountainDon]

Are all your loads (lights, fans, radios, etc.) off the inverter or do you have some direct 12vdc loads as well?

At this point everything that was metered was off the inverter.

When the system is completed as planned there will also be...
... a 24 VDC ceiling fan that will see occasional use in hot and cold weather.
... three 12 VDC 15 watt fluorescent lights that may see 15 minutes to an hour total use on an average day. They will be powered through a high efficiency solid state 24 VDC to 12 VDC converter. I'll also likely use the 12 VDC to recharge the cell phone and a couple other small battery powered items. Or charge them in the vehicle when driving.
... microwave use 800 watt cooking power, 1050 actual power use from the label, for a calculated average of 20 minutes maximum per day. I will be running the Kill-A-Watt to verify actual microwave power use to satisfy my curiosity. I have found that not all appliances actually use the full label rated power.
... perhaps once a week the use of a toaster, 2 slices of bread/bagel

So the loads will be higher once we're settled and fully configured.

Now that we're back home here in the 'burbs for a few days I realize that here we turn on room lights and may leave them on for no good reason. 

[ScottA]

When I did the load calcs for my cabin I came up with 68 amps max. That means if everything was on at the same time and all the recep circuts maxed out it would be 68 amps. Thats very unlikely to ever happen. I expect the normal max to be around 20 amps.

[rocking23nf]

Yeah what sucks is that my electricty bill is 20$ even when the main breaker is shut off because of user fees, and in the summer when using power, the bill is around 25$. So using 5 bucks worth of power. Darn fees.

[Phssthpok]

When I did the load calcs for my cabin I came up with 68 amps max. That means if everything was on at the same time and all the recep circuts maxed out it would be 68 amps. Thats very unlikely to ever happen. I expect the normal max to be around 20 amps.

That 68 amps you quote...is that at 120VAC?

[Bishopknight]

I'll be adding to mine over time but right now I only have 400 watts of panels and 320 AH with AGM batteries. I plan to use this for my office and outdoor lighting. The rest is grid powered.

[ScottA]

That 68 amps you quote...is that at 120VAC?

240v