A small solar system can turn a sunny balcony into a power source. It usually has a panel and an inverter. An inverter changes the panel’s electricity into home electricity. Then a plug sends power into the home’s wires.
Germany has special rules for systems with an 800-watt inverter. However, local rules are different. (bundesnetzagentur.de) In Japan, your power company may require a formal connection process. You may need an application and safety documents. (tepco.co.jp) Do not buy a foreign kit and simply plug it in. Ask your power company, building owner, and an electrician first.
Imagine a sunny afternoon at home. The panel helps run a fan and a laptop. If they need more power, the grid supplies the rest. The grid means the public electricity network. At night, the grid supplies all the power.
Most connected systems also stop during a blackout. This protects workers and nearby homes. (kansai-td.co.jp) Small solar can save some electricity, but safety comes first.