How Mirrors Could Solve our Energy Problem

Hi Diana, great video, as a energy engeneer I love this kind of divulgation and all the effort you and other put into teaching people about renewable energy sources.
At 4:52 you said that saturated steam is vapour at high presure that contains also liquid in it. I though you wanted to say superheated steam, but then you say that both states of water exist together because the pressure and thats technically true, being a physicist I know you know more thermodynamics than me, and were oversimplificating. But it is bad to expand in a turbine.
It's really difficult to explain without a couple of mollier diagrams of water, but you can look up for them, specially the T-S one.

When you heat water it starts increasing it's temperature until it reaches(at 1 bar) about 100ºC. This is called saturated liquid, and all the energy you put in went to increase it's sensible heat.
Then, all the energy you put into boiling water doesn't increases the water's temperature, but it's absrobed into transforming liquid water into water vapour, wich is called latent heat. This is due to the vapourization enthalpy,  wich is how much energy is required to change the state from liquid to gas.
When all the liquid you had has become vapour, now you are in a state known as saturated vapour, and all of the energy you put in them from now will now increase it's temperature. 
The vapour you keep heating is known as superheated vapour, and it will reach temperatures as 650ºC at pressures about 20 bar

If you expand the saturated vapour in a turbine, it will start giving it's latent heat back and condensing, and the water droplets hitting the blades of the turbine will ruin it. 
That's why steam turbines work with superheated vapour, wich will give the turbine it's sensible heat but preventing whater to condense inside the turbine.
It is so important to avoid condensation, that steam turbines have multiple stages, and in every one of them expand the superheated vapour to just before reaching the saturated vapour point, and the reheat once or twice the vapour to keep extracting more energy from it before sending it to a condenser stage.