If you take two identical charges at a certain distance
The energy is still conserved, you are transforming the potential energy of the charges in kinetic energy. The potential energy is decreasing, the kinetic is increasing, the total energy is constant.
The Universe had some big potential energy at the beginning that is transforming in kinetic.
We still don't know very well what was this potential energy and we do not know how (through which force) this potential is changing in kinetic, but we can assume that the total energy is still conserved.