[gizmo686]

Anything that requires an electrician to come and modify your mains connections (followed, presumably by a municipal inspection), defeats the main benefit of balcony solar, which is that it is a commodity unit that can be installed by non-experts without any red tape.

Further, the utility's safety concerns do not require any shut off on the mains. Their safty concern is not a new backflow of current; but a backflow of current into an otherwise non-energized grid. Grid-tied inverters will not do this. If the grid goes down, they shut themselves down without any need for an upstream shutoff.

The utility's may have a reasonable business object to back-flow if their meters are such that backflow forces net-metering. Around here, that is a non-issue because net-metering is the law for residential connections anyway. Even in juristictions where net-metering is not the law, I don't find this convincing. The limited capacity of balcony solar means that it won't actually happen in any significant amount, and if it does become a problem, they can shoulder the cost of upgrading their metering equipment.

[rickydroll]

The simple plug-in and go balcony solar is going to be constrained in many ways. Zero export solar is more sophisticated, yes, does require electrical inspection, but given that it lets you add extra solar panels, battery storage and keep all the power you produce on the house side of the meter. There is some win there. Additionally, if you live where there is time of day rate changes, you can store up cheap energy at night and use it during the day when it's expensive.

Net metering is common, but not everywhere and frequently there's a pricing differential between what you buy and what you sell. My mother leased her solar panels from SolarCity/Tesla. She buys electricity at $0.12 a kilowatt hour, but sells at $.09/kwh. Some of the regulatory shenanigans I've seen regarding balcony solar include no net metering. If you produce excess power, you get no credit for it.