In a grid down scenario, even if you’ve taken the measures necessary to ensure that you have power, it would be a good idea to have candles and alternative light sources that you can turn to.

If you are using a solar generator, or a generator in general, you want to conserve that energy for the most important times of the day. At night you probably won’t be using many appliances, and for most of the year it is cooler at night and you won’t need any climate control.
Candles will also be a more stealth measure to light your home at night as opposed to having lights on. While you should have covers over your windows, you might not, and having lights on or the blue glow of the television will advertise to all of the neighbors that you have power. This will make you susceptible to random visits and favors being asked. You might enjoy helping people, but this will be a totally different environment and having as little contact with others is the best measure.
If you are health conscious, you probably don’t want the cheap heavily scented candles from big box discount stores. You’d be much better off with something natural like beeswax. Heavily scented candles typically give me a headache, and I am trying to avoid headaches as much as possible while I’m bugging out at home.

A flashlight will also come in handy, but constantly holding it in your hand can be a bit of a bother. I prefer to keep a flashlight by my bedside so I can go from pitch dark to visibility within one second. If you hear a noise that startles you, bumbling to find your matches or a lighter to light a candle isn’t very prudent.
You can live exclusively by candlelight at night, and you could also have the option of possibly using a kerosene lamp, which is what everyone used before the invention of electricity. They work pretty well, and you can light up a whole room with one lamp and with it being portable you could move it with you from room to room. I don’t currently have a kerosene lamp, but I am planning on getting one and I do see the value in it. I think candles a flashlight and a kerosene lamp would suffice for all the alternative light sources you need.