How can a turbine store energy and be used as electricity?

A turbine doesn’t store electricity, it generates electricity. Something (heat, water, wind, etc) makes it turn which causes a magnet inside to turn inside of a copper coil which generates electricity. Some type of battery is required to store it.

A turbine generates energy (electricity), you can either store electricity in a battery or a compositor, the compactor is very short term

you can use the turbine to create electricity. You can use the electricity to pump water to a higher level, then use that water to run the turbine to create electricity when you need it.

There are several systems, that do this. A big one in the UK, pumps water into a big lake in times of low demand, then in times of demand, water is released into up to four turbines for short power surges.