Agios Efstratios is a Greek island in the north-eastern Aegean Sea. It has 250 people. Before, it got all its electricity from fuels such as oil. Now, wind and sun provide 91% of its electricity. This stops about 1,000 tonnes of a gas called carbon dioxide from entering the air each year.
The European Union helped pay for the project. Batteries store extra electricity. They give it back when wind and sun do not make enough. Computers control the system.
In winter, extra energy heats water. Tanks store this hot water for heating. One local man says the heating is quiet and cheap to use. A local official sees the project as an example for other Greek islands.
