Im setting this up right now on my balcony, which will make me the third apartment in my building to install a system like this.

All you need is some standard solar panels (they all use the same connectors so you can mix between brands often) and an inverter box.

I got three used panels for 10€ a piece a few months ago which i will slap on the outside of the balcony.

This 800W grid synchronizing inverter can be had for 100€ currently and even has two MPPT trackers for separate panel strings (for when not all panels are oriented in the same direction).

This is what the end result typically looks like:

Uh, you are aware that your laptop charger is providing DC right?

It is being sent into the general electrical network of the house/flat, where it lightens the base load. There is a maximum of 800W that you are allowed to feed into your home network. Anything bigger is subject to different rules and approval by the electrical service provider.

800W aren't a lot, but it can half the cost of your washing machine run, make your fridge power free and let a PC idel or a NAS run. These balcony solar generators usually make back their costs within 5-8 years if you calculate what you'd otherwise pay for the electricuty.

These setups come with a fitting transformer and you feed their generated power directly in your home power lines via normal plug. It's quite neat actually in my opinion!