Batteries are used now more so that ever. All of the hand held controllers, telephones, game consoles, portable radios all need batteries for their source of electricity.
A portable generator could be beneficial to a construction worker in that it could be used to power their tools while at a construction site that does not yet have electricity hooked up. A housewife on the other hand could use a portable generator a backup source of power in case the electricity went out in her home.
Either a battery or a portable generator.
Portable generators can be used for many purposes. Some people keep portable generators at their home for use in the event of a power outage caused by storms or other events. Some people use portable generators while camping or for a source of electricity in remote locations.
A generator is the best kind of power source for outdoor lighting because it works regardless if the electricity does or not. It's also very portable, and cost-efficient.
A battery is a source for electricity. A flashlight and a radio are not a source for electricity.
Candles, gaslights (in cities) and oil burning lamps and lanterns. Of course there is also the oldest source of light besides sunlight, and that is a fire. If you needed portable light, use a torch.
Portable oxygen concentrators are energy efficient and use as much electricity as a television. Most portable oxygen concentrators can run 4 hours on battery life alone.
a laser IS NOT a electricity source its a light source and no its not that good as conductor of electricity
No there isn't No there isn't
Oil is the main source of electricity worldwide.
coal is the main source of electricity in Germany