Technically energy is raised during the build-up to orgasm, orgasm itself releases most of that energy especially for males. These facts are essentially the energy raising system of Tantra. Their solution to 'storage' is to prolong the 'build-up' as long as possible and to not orgasm.

The dan tien is probably the best place to store lots of energy in the body. Considerable amounts of energy can also be stored in the aura though is does typically leak away in less than a day.

Clearing/cleaning your energy system will allow you to store larger amounts of energy in your body without triggering any Kundalini.
Without first clearing your energy system, high energy levels can cause health problems even without Kundalini.

I don't consider PC (kegel) exercises to be at all helpful in increasing energy storage safely. It does lead to better control of orgasm thus allowing higher build of energy levels before orgasm.