I have been playing around with solar power, buying two 425-watt panels and a power station that can store 2 kilowatt-hours of power. However the power station is limited to 500 watts of input, so I am often wasting power. It is still helpful to have both panels if I want to have any chance of filling the power station in a day. The power station was $600, the same price as both panels, so it would be nice if you didn’t have to buy your own storage. Plug-in solar is a way of feeding solar power directly into your house through a standard electrical outlet. Because a 15-amp household electrical circuit can only carry 1800 watts, the system has to be sort of small, often capped at 1200 watts. A plug-in solar setup has a solar panel, an inverter to convert DC solar power into AC, and a plug. Utilities don’t like it because if your power line is severed, the end coming from your house will be electrified. If the line is severed past the local transformer, your 120 volt could be multiplied substantially. Newer and better inverters monitor the household power and if they sense a blackout, they immediately cut power, so this is something that has been solved. Accordingly a few states have made this legal.
The idea is that you can offset your baseline usage with solar, but the problem is, what is your baseline usage? During the day, when there is plenty of sunlight, I might have a couple of lights (with LED bulbs) and an internet router and server, but everything else is on demand, like if I use a computer or watch TV, which isn’t all the time. Nor is the compressor on the refrigerator running all the time or the air conditioning. So my baseline could easily be less than 100 watts. My two panels can produce 850 watts at best, but it isn’t often that my house is using that much power.
So the question is what happens to that power if I don’t use it? In some places, it can go back out to the grid and maybe you even earn credits for every kilowatt-hour you supply to the grid. But the power company would rather pay you their production cost for power you provide than give you full retail price. I think in Georgia the power typically doesn’t go anywhere, so it is just never used at all unless you have everything professionally installed, inspected by Georgia Power with maybe a new meter that you have to buy, pay fees, and then you can start getting paid a fraction of what you pay for power. Even some payment is better than nothing and at least the power would get used, meaning Georgia Power burns less natural gas.
Another issue with plug-in solar that is technical enough that a lot of people don’t talk about it, has to do with the nature of your 120V power circuits. If you want to dump power into the circuit, the power can power anything on that circuit, but it can also go back to the breaker box and power everything else in the house that uses that hot wire. The problem is that generally houses have two hot wires, so you are only providing power to one of them. The other half of your circuits are using a different hot wire so they are powered only by Georgia Power. 240V circuits use both hot wires, so your dryer, electric stove, and HVAC will get half of their power from the hot wire that you are dumping power into. Another problem is it is kind of hard to tell which outlets are using which hot wire, but if you want to make sure you are making the best use of your plug-in solar power, you need to know. You can go the breaker box and figure it out, but I have a fuse box subpanel and I don’t know how that breakdown works with its four circuits. There is a device that can help tell you by figuring out the difference in the signal timing, but I don’t have one of those. Even if you know, maybe some of the things that you power are on the wrong hot wire. I think there are inverters that can go to a 240V circuit and therby power both of the hot wires. Maybe even one that has output for both and would possible plug into two different outlets?
A neat aspect of using a plug-in system would be that I could plug one of my panels into my battery directly and also draw power from a wall outlet which could get power from the other panel using the plug-in inverter. The Aferiy is capable of charging itself from two sources like that. With the battery I can set how many watts it is drawing from the outlet, but as clouds go by or shadows fall on the panel, I can’t guarantee that all of that will be coming from solar. That could work during peak hours when there is consistent sun, but I don’t think it is a great solution.
There is also a type of inverter called a hybrid inverter which can send solar power to either a battery or to my home grid or both. That could be a way of utilizing the full 850 watts I sometimes collect without wasting it.
The other option would be to have gotten a battery that can accept more than 500 watts, but that ship has sailed. I don’t think the Aferiy was a bad choice and there are other models out there that accept even less and plenty that have less than the 2 kWh storage of the Aferiy.