Do you account environmental impact of manufacturing of this device, shipping and energy used to place it in the store, time spent on customer service, people transporting it to their homes etc? How hanging it off balcony will offset that? Isn't that just virtue signalling?
Solar is cheap in terms of environmental impact and embodied energy as well. The balcony and plug-in part just makes the install cheap, which is by far the largest cost of residential solar.