Today it came to my mind why we always use heating to make energy. There must be ways to start from much colder unless we start with the sun. The sun should be our only source of high heat in space when we make energy. 

For example we could fill a tank with cold gas from a cold planet and send it direction sun where we could install a space turbine that turns on the heating and expanding gas while releasing it and we could also use it in an other process afterwards.

An other example would be blocks of ice that we transport direction sun and turbine-power-plant and use it to process water and gases afterwards.

We could even use space itself to freeze and boil in a closed turbine-system where for example ocean-water freezes over and expands while boiling close to the sun to turn turbines.

These are just a few fast idea's how we should change our mindset about making energy. Go as low and primitive possible and use it with high-tech.

Grtz, Dirk.