To expand on this a bit further, the individual kanji mean "fruit", "house", "departure", "electric" and it's more about those meanings and the combination of those meanings (and their innuendos) than it is about the meaning they take on when they're all together. The reading for the characters together is almost identical to 自家発電 which actually is "own home power generation."
Normally, 実家 means "parent's house" but in this case it's going for the "fruit house" meaning which is an obscure innuendo referring to the home of love nectar. 発 is "departure" and, as Houshou's Ichimi know, is also an innuendo for climax. The 電 means "electric" and refers to the sensation of the act but is mostly there to obfuscate the innuendo as otherwise you just have "leave your house."