Whilst living off-the-grid in our portable tiny house, we use traditional oil lamps for our primary source of lighting.
"[Y]ou grow some castor seed, press it, get oil, put in any pot, and one wick, the light is there. So even understanding that you have improved the lighting system, but that is not the only necessity of my life. But to improve from the castor seed lamp, castor oil lamp, to this electricity, you have to work so hard. You have to go to the middle of ocean and drill it and get out petroleum and... In this way your real business of life is finished.
“The energy and the intelligence you got for your self-realization or your, this precarious position, constantly dying and taking birth in various species of life, this is your problem, and this was to be solved in human life, you have got advanced intelligence, but that intelligence is utilized from castor seed lamp to the electric lamp. That's all."
New Vrndavana, June 24, 1976