For those interested the protected socket idea here's some blurb from the manufacturer:
Sunny Boy 3000TL-US
SMA has recently unveiled its newest line of grid-tie inverters with a variety of new and improved features to help system owners get the most out of their systems. These new UL certified inverters continue to raise the benchmark in solar inverter technology. The Sunny Boy 3000TL-US comes standard with an impressive list of features.
Transformerless for higher efficiency and lighter weight
Dual maximum power point tracking for more design options
Reduce effects of partial system shading with OptiTrac™
Secure Power Supply (SPS) provides daytime power if grid goes down
Sunny Boy 3000TL-US comes with a Secure Power Supply that is able to send up to 1,500 watts of power to a dedicated outlet in the case of daytime grid failure.
So maybe 13.5 Amps @ 110V on the circuit max. Maybe enough for a small window AC, but would be touch and go. But that amount of power would be very useful for all the other suggestions by Samclem.
I upgraded to the 4000-watt version of that inverter about six weeks ago, after our 10-year-old Xantrex died.
The SPS is actually just five connection points (inside the inverter's black lower panel, behind the LCD display) for you to wire in a switched receptacle. You still have to provide the switch, the receptacle, the conduit, and the remodel box to install it where you want it. Our inverter is on the outside of our garage wall, so we put the SPS receptacle on the inside of the wall. Unless you're comfortable doing that type of wiring, she might want to ask the electrician to take care of it as part of the installation.
I think it's more of a gimmick than a feature. It's only going to power your loads when the sun is out, so I wouldn't be eager to run an air conditioner on days when clouds are crossing in front of the sun. I don't think that I'd try to run a fridge on it, either. But it'll run our 100-watt pump for our solar water heater (which stays hot for a couple of days), and it'll run the air pumps for our aquarium (which will hopefully keep the fish alive overnight). But it only cost me about $10 in parts and an hour to connect all the pieces.
If she's interested in monitoring the array's performance, SMA also sells a "Webconnect Speedwire" dongle that plugs into a ribbon cable fitting (also behind the LCD display) and terminates in a couple of RJ-45 jacks. She can either add a wireless network adapter or plug a hardwired Ethernet cable into her router, download some software onto her computer, and monitor the array directly. It retails for $300-$350 and might be a useful negotiation point.
But the real use of the Webconnect box is the ability to configure the inverter directly. Here's another reason you might care about that.
In the six weeks I've had this SunnyBoy, it's tripped twice on an arc fault circuit interrupt safety feature. The AFCI system is supposed to look for problems on the DC side, but the inverter is trying to detect a brief signal up in the 100+ MHz frequency range. Ideally it's a loose wirenut with the current arcing across the wires, or a loose MC plug that's not making tight contact, or a wire that's rubbing and frayed on a sharp bend, or even a bad solar cell in a panel. However the inverter has also been known to trip on high-frequency transients from electronic dog fences, high-voltage transmission towers, A/C compressors starting or stopping, and even feedback from the local utility through your service connection. One company even noticed that their inverter tripped on AFCI whenever a warehouse ceiling exhaust fan (on a thermostat) started up. Once the inverter shuts down on an AFCI you have to manually shut it off (switch of the DC connection from the panels and open the AC breakers) and restart it (switch the DC connection back on and shut the AC breakers, then "knock" on the front panel to clear the AFCI fault). But the only way to know that you've had a AFCI trip is when you check the display panel, and in my case it took a few days before I noticed.
The AFCI detector is required by recent updates to the American electrical code, and it's stringent enough to produce more than its share of false alarms. SMA has to include it to remain code compliant, but they've also added the ability to toggle it. If you have the Webconnect system then you can reset the AFCI feature... or even shut it off. You can also have your inverter e-mail you whenever it has an AFCI trip or other out-of-spec readings.
If you have the Webconnect system you can also reset your inverter to maintain its grid connection down to as low as 57 Hz instead of the default 59.3 Hz. It turns out that our local electrical utility has a habit of dropping grid frequency lower than 59 Hz, so our Oahu PV installers have known for years to reset the low-freq trip to 57 Hz.