It can't be more or much more than the 800W as currently done in Germany because it would not be safe with the way electricity is delivered to a home.

The reason is: when you pull electricity from the grid, the fuse would blow if you tried to pull too much current (e.g. you connect four hair dryers on the same outlet). It blows to prevent the wiring in your home from overheating and catching on fire. With balcony solar, you plug it in your home outlet which is already behind the fuse, which means the fuse cannot react and cut off power if you try to feed in more than the capacity allows. You could be maxing out on the current you are pulling from the grid, and then on top of that you would be adding your balcony solar.

Why it's allowed at all in Germany and other places is because the fuse will blow above 10A and the wiring in the house is 16A, so there was always a buffer or overcapacity in the wiring, presumably just in case. So they allowed 800W of balcony solar which is roughly 3.5A and still there is some wiggle room left.

Also why pull from the grid at all: your appliances actually just use the electricity from the grid. In Germany and I guess most of Europe they run a three phase system, so your balcony solar might not be in the same physical circuit as your appliances in use. With balcony solar your meter just offsets your consumption with whatever you are feeding it at the moment. From the grid standpoint if you are running something using 800W and feeding in 800W, it's 0.

Of course it can work without this too, but this defeats the purpose of balcony solar, which is plug it in and it works simplicity.

▲

harmmonica an hour ago | parent [-]

This is very interesting and helpful info! I guess my fantasy is that a standard electrical panel would eventually have a literal plug on it where you could plug a larger system in, just as you would an outlet in the balcony situation, and then it would I think be, using your word, in "front" of the "fuse" (using quotes because I'm not sure I have the behind/in front of language correct, and when you use fuse here in the states it would be a breaker, I guess, not an actual fuse). This solution would of course have to mitigate things like fire risk, or blowing up the house or grid itself. I'm just hopeful it's coming because I think the install rate would go through the, pardon me, roof.

▲

Kaliboy 31 minutes ago | parent | next [-]

The post you replied to isn't fully correct. I'll tell you how you could do this in many ways that prevents the fuse problem.

There's 3 ways to run solar.

Grid tied, grid backed and off grid.

I live on a farm and am off grid. The solar inverter is my "utility". After the inverter I have my main breaker. The inverter makes 5 kW max at 230 volts, so my fuse is 5000/230 = 20 amps.

I'm outside the US, regulation is a suggestion here everyone ignores. So many many houses have solar panels here to offset grid costs ($0.60 per kWh).

The main way we do it is make it grid backed. This means the inverter creates power that is in no way mixed with grid power. It forms a microgrid within the home. All ac's are connected to this. This can be done in the electrical panel as its just rerouting wires to fuses.

So then you have your 20A fuse behind the inverter, and smaller fuses (which you should already have) to your house loads. Btw you guys run 110v so your fuses are probably double the rating of ours.

When you do grid backed a battery is nice, since it helps prevent using the grid when a cloud passes by, it forms a bit of buffer. A 5kWh battery already helps. At night the grid powers the loads.

Grid-tied is the one nobody here uses, so you can feed back to the grid. This involves complicated electrical stuff so you don't electrocute the line workers. Plus it gets complicated with split phases and such.

Not to mention utilities pay less than what they ask you for the same kWh.

In the case of balcony solar you can feed the inverter utility power and connect your AC to the inverter. It uses solar power first and takes the needed diff from utility.

	▲	harmmonica 16 minutes ago \| parent [-]
		Know you don't want to dox yourself, but .6 is... rough. Like super rough. Would love to know where this is, but no pressure. Thankfully you're not relying on it completely. And oh what I wouldn't give to know the incidence of deadly maybe very-damaging electrical fires there given your well put "regulation is a suggestion here everyone ignores." Because if the incident rate is no worse than here you can make some assumptions that the regulations here are overly burdensome. I'd be remiss if I didn't say that regulations are oftentimes written in blood; it's true in the case of electrical generation, distribution, installation, but it's also a glib way to stand in the way of solutions that improve peoples' lives.

▲

locallost 8 minutes ago | parent | prev [-]

I imagine it could be done like thus, but it is not, there's no infrastructure like this, so it's a moot point. Balcony solar was allowed so it's a hassle free DIY solution. You also don't get any money for feeding into the grid, but because you save a lot of money on installation costs it's still worth it.