Long time dreamer wants to jump in

Everything is on the table, Tesla, Sunrun, Costco, battery backup, DIY, plx devices legion solar.

REQUIREMENTS
* non roof install because I won’t be able to wash the panels on my second story roof.
* we have a south facing covered deck which is the prime candidate. It is 20 feet wide by 15 feet deep.
* there is a power outlet which made me think the legion kits might be the simplest install and it happens to be DIY.
* I want at least a 4KW system but can start with a “starter” setup of 1.8. Legion has 150 watt panels and 12 of them can supply 15 amps max to the outlet. Then I can look into future additions later.
* if I can keep things simple and just plug into my house wiring via either a power outlet such as legion or via a breaker box circuit. I don’t really want to ask Pge for permission or get into net metering.
* I’ve been using an average 6.2-ish MW of power yearly. That translates to something like a 2KW setup. And since the sun don’t shine here in NorCal the same number of hours year round, double that and I get my 4KW need.
* I dont really want batteries for night power. Until the things become safe enough that they won’t blow up.
* I do want to use my PV power during the day during an outage.

Can someone point me in the right direction on what equipment I need.

Washing isn't really necessary.

20 x 15 = 300sf or 28m^2
One full sun is 1kW/m^2; panels can harvest 14% to 20% so up to 0.2 kW/m^2
28 x 0.2 = 5.6kW (STC) available, about 5kW (PTC)

Power outlets with PV plugged in isn't a UL listed approach. Possible problem is 20A from breaker + 15A from PV feeding 35A through 12 awg to outlets downstream, causing overheating and a fire.
Should go direct to a dedicated breaker.

I like string inverters. One or more series strings of panels go to a single inverter. Cheap and efficient. Quality ones last for decades. I use SMA, but there are several other good brands.

For a cost-effective small-scale system that can provide for an outage, look for an all-in-one (MPP and others have low cost models, SolArk is among the expensive ones.) If batteries optional you may be able to run some loads given enough sun. But even a cheap lead-acid battery would greatly improve surge current to start motors, and provide power during brief cloudy times or high loads like a microwave.

For panels, check out SanTan Solar. Or other local suppliers if avoiding shipping is convenient.

Design everything to work together (and bounce it off the group here) before buying anything.

"No permission solar"

If you get a zero-export system (current transformers clamped around utility feed so inverter can avoid exporting), that makes things simpler.

Hedges said:

If batteries optional you may be able to run some loads given enough sun. But even a cheap lead-acid battery would greatly improve surge current to start motors, and provide power during brief cloudy times or high loads like

Click to expand...

I personally can’t wrap my head around not having any batteries. So many advantages including the obvious overnight or grid-down backup. As a ‘buffer’ it is less obvious but maybe more useful?

Properly configured a small “cheap lead acid” battery array would provide nice “buffering” and performance benefits- and if not deeply discharged a fairly long service life.

Hedges said:

Home

legionsolar.com

"No permission solar"

If you get a zero-export system (current transformers clamped around utility feed so inverter can avoid exporting), that makes things simpler.

Click to expand...

Can you expand upon that idea. I’m interested in having power available from panels when utility power goes out during the day and off batteries at night. Ideally I’d like to remain on my side of the fence and not have my utility involved with my power choices.

To operate when grid is down, you need either a transfer switch (to let a generator or inverter power the whole house), or a relay built into inverter to disconnect grid so inverter can supply loads downstream of it.

An inverter that uses current transformers to measure current from/to grid can implement zero export. It will backfeed the house which is connected to grid, but it reduces output if it senses power being exported. That lets 100% of PV be used if your house draws that much power or more, and doesn't require the whole house to be downstream of the inverter.

If you get an inverter with PV input, battery input, and current transformers, it will give you PV & battery backup during power failures, and it will let PV feed other loads in your house while the grid is up.

There are a range of products and prices, like $800 to $8k or more. Your 2kW or maybe 4kW PV is relatively small, so I assume you want a reasonably priced solution.
You do have to consider what loads you want to power while grid is down. Motors draw about 5x their rating as a surge or maybe 1 second when starting, so inverter needs to deliver that.