Humans can’t see well in the dark, we need lights. Having several choices of survival lights will insure you are never in the dark. Candles produce air pollution and are dangerous. The same with oil lamps and those propane camp lanterns should never be used indoors. Rechargeable LED lanterns and flashlights provide a safer and healthier alternative. Many are available with wind-up dynamo or solar charging options. Regular battery flashlights are fine for limited use as changing batteries can be costly in the long run and they do have a shelf life. Keep a rechargeable solar flashlight in a window sill and it will always be ready to use.