Solar powered office

[MesaGuy]

Hello,

Frist off I am very new to solar.

I have a small detached office that I would like to run using solar. Right now, I am running it from the grid. The most solar I could put on the roof would be about 800 watts. I am thinking of getting a Growatt 24V SPF 3000 and SOK 24V 100Ah LiFePO4 Battery and (4) 200 Watt 24 Volt Solar Panels to power this. I am sure I will still need to rely on the grid to charge the battery when cloudy etc. I live in coastal southern California. I would be running a couple of computers and a space heater for couple of hours a day.

My question is, does this sound reasonable?

Thanks so much.

 

[chrisski]

I don't think its reasonable, at least money savings wise and what I consider reasonable for an office, but a good power requirement would need to be done with an energy audit.

The battery you mention has 2400 total watt hour, and that will get you 2000 watt hours I'd feel comfortable using. You also need to plan to the worst day, which I will say is keeping your 500 watt heater on for 2 hours, which burns this down to 1000 watt hours or 50%. 1000 watt hours is where I'd stop because I want day 2 of power, so I won't go below 50% usable power.

For discussion, perhaps you can make 3200 watt hours per day for your system. In my signature block there's a off grid calculator for a better prediction for your 800 watts of panels. So, the max you can make in one day is the result of that calculator, and if you want to totally recharge the battery bank after one cloudy day, you'd be limited to 1600 watt hours of power. So, maybe you could run the space heater and laptop for a couple of days in a row. Also, to get 3200 watt hours of power, you'd need a second battery.

It's also hard saying two hours. I could not limit myself for only 2 hours a day.

A good energy audit would be done by a killawatt meter with appliances you already have. The space heater really is a huge draw on power, and if there is a workaround, than that will help/

 

[Short_Shot]

Not sure what kind of computer usage you do, but I can tell you that my computer and typical use would flatten that battery in about 4 hours, never mind anything else.

If you've got a really low power laptop or something you might make that viable but you've really got to do a thorough energy audit of the whole setup and I can all but guarantee you'll need a lot more battery.

2kwh with a 1000 watt space heater (which is smaller than most people buy) would run under two hours. It actually would run significantly less than that with the efficiency losses of the inverter.

Most people don't buy space heaters much less than 1000w because they're almost worthless at that size, unless you're solely using them to keep your feet warm. Pun intended.


You'll want to buy a "kill-a-watt" type energy meter to plug in to each device during normal use to understand how many watt-hours they all require for your usage.