Power after the electricity shuts off should be producible via means other than simply using a fuel generator. For instance, small wind turbines IRL are used to power battery chargers and mobile homes. Subsequently, they could fit the role of a power source that is both renewable and quiet, unlike the fuel generator, provided that the player could find any, or construct them once they reach a high enough mechanical and/or electric skill. The obvious trade off would be that they're less efficient. Furthermore, I think also giving the player the ability to find and/or build home batteries, again under the condition that they have a high enough mechanical and/or electric skill.