My energy doesn't go up.

[freeico]

Power is not comulative resource. Every level of panels will give you energy, you can see in tables how much, additionaly you can build solar satelite to add energy which depends to planet position. If you have free energy you can build. If you go out of energy you just need to build new level of panels, or few new solar satelites.

[freeico]

No it will never accumulate.
Its like the power supply at your home. It is let say 220V all the time. If you need to be 380V you need more powerful source, but it wont increase in time. It is just as it is said to be for given level.