Solar-powered shed-turned-office supporting air-conditioner

[yi2020]

I have a 10'x12' shed, with a glass door and two windows, and 194 sqft of root at a 2/12 slant (it's a bit bigger than the size of the shed).

I want to run air conditioning in there (min-split like this), as well as a few screens, wifi router, my computer, lights, etc. The AC in the link has 1080W rating, with max of 1340W (see https://images.thdstatic.com/catalog...518b0f0c53.pdf).

I've done research on other websites, and came to a conclusion that what I need is:
* 8x320W panels (that's what the roof of the shed can fit), like these: renogy.com/320-watt-monocrystalline-solar-panel (NOTE: my shed's roof is facing north, at a 2/12 slant, my latitude is 38 degrees north)
* A 3500W 48v inverter/charger: https://www.renogy.com/48v-3500w-sol...erter-charger/
* Four batteries to get to 48v at the required amps: https://www.renogy.com/deep-cycle-ag...12-volt-200ah/

Obviously, on days where there's little sun, I won't be able to run the A/C, but then again - I won't need it (other than really cold days where I'd like to heat up the place, that's an issue I haven't solved yet)

Is my design making sense? Will this work?
What am I missing here?

[SunEagle]

Looks like you plan to spend a lot of money. I hope you have the technical experience to do the install. My first question is how far is the grid from this building and have you looked into getting power that way instead of doing the solar / battery install?

[bcroe]

There are buried cables bringing power up to 750 feet from my meter,
at 240VAC losses are controlled, it works summer and winter, sun or no
sun, no maintenance, and it is a far more economical system than trying
to run off grid solar. How far away are you? Bruce Roe

[yi2020]

The shed is in my backyard, about 100-150 ft away from the meter. It may be cheaper to have the shed connected to the house (am getting a quote in parallel). But, then I'm not using the shed's roof space to generate electricity, and instead am paying for it from the power company. (the house has its own solar setup too, but it breaks even on an annual basis on net metering)

From a cost perspective, the solar option will likely be better in the long term.

[bcroe]

If you plan to run summer and winter, chose carefully a mini split with
the outside temp range to cover your location. And mount it higher
than your snow acumulation. That is what is operating here for 4
winters. Here the primary burden is heating when the outdoors are
well below zero F, AC is so easy, that half my capacity is turned off in
summer. But with all your equipment helping winter heat, AC might be
the bigger problem. Figure your heat loads. You might look at a way
to ventilate the equipment directly outside in summer, instead of
loading down your AC.

The latest lines here are aluminum triplex (4 conductor available) of
direct burial type, it must be 2 gauges bigger to match copper loss
performance, but even then might be only 1/3 the cost. I have a trencher
for the required 2 foot depth, but usually it can be rented.

More panels, sure put them up with a grid tie inverter at the shed, with
agreement of PoCo. Get the power, no battery problems.
good luck, Bruce Roe

[yi2020]

So we live in an area that goes up to 90's, even low 100's degree F in the summer. It goes down to 30's, high 20's in the winter (frost etc). So there would be more need for cooling A/C vs heating.

So Bruce what you're suggesting is to basically send the solar power back to the grid just like my main solar panels do, and not deal with storing it / battery within the shed, correct? Did I understand correctly?

[SunEagle]

The shed is in my backyard, about 100-150 ft away from the meter. It may be cheaper to have the shed connected to the house (am getting a quote in parallel). But, then I'm not using the shed's roof space to generate electricity, and instead am paying for it from the power company. (the house has its own solar setup too, but it breaks even on an annual basis on net metering)

From a cost perspective, the solar option will likely be better in the long term.

Maybe or maybe not when you add in the cost and maintenance of a battery system

I just ran a 100amp U/G service about 100 ft to a subpanel and spent a lot less then $500.

[yi2020]

Maybe or maybe not when you add in the cost and maintenance of a battery system

I just ran a 100amp U/G service about 100 ft to a subpanel and spent a lot less then $500.

I want to l live where you live
Where I live, it'll be easily $2000 - and I'm the one doing the trenching.

[azdave]

I would connect the shed to the house and then if you are able, add grid-tie capacity to compensate for the extra load. I would never consider a stand-alone PV system for the shed unless there were no other options. The POCO is the cheapest bank bank you'll ever use and maintenance-free too.

[SunEagle]

I want to l live where you live
Where I live, it'll be easily $2000 - and I'm the one doing the trenching.

Even if it costs you that $2000 it will still be cheaper in the long run then what you proposed in your first post.

I would agree that a grid tie system can pay for itself but a soar / battery system will not provide you enough power when you need it and will cost much more then a grid connected system. Just my thoughts but again you can spend your money anyway you want.

[yi2020]

I would agree that a grid tie system can pay for itself but a soar / battery system will not provide you enough power when you need it and will cost much more then a grid connected system. Just my thoughts but again you can spend your money anyway you want.

Well, the reason I came here is to learn from experienced people
Based on the responses to this thread, there's a high chance I'll abort the solar project and just hook up to the house. So for me, at least, it's been very helpful

[bcroe]

So Bruce what you're suggesting is to basically send the solar power back to the grid just like my main solar panels do, and not deal with storing it / battery within the shed, correct? Did I understand correctly?

Yes, my opinion. If you are digging that trench in 95F like I did a couple years
ago, an old furnace blower like the brown one here can make it a lot more
tolerable. That El Cheapo trencher had no propulsion, but the boat winch I
attached worked even better. Just needed to find anchors (trees) for the chain.
Bruce Roe

Trn4Jly.JPG

[SunEagle]

Well, the reason I came here is to learn from experienced people
Based on the responses to this thread, there's a high chance I'll abort the solar project and just hook up to the house. So for me, at least, it's been very helpful

Look while I support solar I also support not wasting a person's money or installing something that is unsafe. I understand your desire to use solar but when it comes to AC loads I really don't think a battery is going to cut the mustard.

Now if you only had small loads then maybe a solar/battery system makes sense, especially if you don't spend more then it should cost and if the system is portable like the one I built for use at RC plane fields.

[J.P.M.]

Well, the reason I came here is to learn from experienced people
Based on the responses to this thread, there's a high chance I'll abort the solar project and just hook up to the house. So for me, at least, it's been very helpful

Welcome to the forum of few(er) illusions. But before you abandon the project, I'd suggest you learn more about the solar process, including its capabilities but mostly about its limitations. Otherwise, unless this is a learning project, I'd just run power from the house ? Cheaper, faster, easier.

[yi2020]

So I just got the quotes:
$5000 to add a 40A breaker to main house, run cable and conduit up to shed, install two circuits in shed, wire mini split. Geez! Still think solar is expensive?