As lighting our world has become more efficient over the centuries, total consumption has increased manyfold. That’s likely to happen in the future, as well, says resource economist Rusty Pritchard, president of Flourish. He writes on the Flourish Blog:
Light is a good thing (didn’t God himself say so in Genesis 1?). And the law of demand in economics suggests that if the price of a good thing goes down, people will always want more of it. (The concept of “enough,” although biblical, has never really caught on in economics.)
This was the case when gas lighting replaced candles and whale fat—cheaper light led to higher demand, including street lights (!). The conversion to more-energy-efficient electric lights led to another increase. We now consume 100,000 times as much light as Western Europeans did in 1700.
Light is so much in demand that the increase in consumption wiped out the gains from efficiency, so more energy rather than less was used. The same is expected to occur in the future, as solid-state lighting replaces today’s compact fluorescent lamps, as reported in the Economist news magazine. Those lights will be better for the environment if and only if we are satisfied with today’s level of lighting. But we won’t be, if history is a judge. Efficiency is expected to increase by a factor of three, while consumption of light is expected to increase by a factor of 10. We’ll need twice as much energy to make that light.
Of course we shouldn’t slacken our efforts to conserve energy. Rusty concludes: “None of this means we shouldn’t pursue the gains of energy efficiency, it just means we can’t expect relative prices to make us virtuous people. We still have to confront the culture of “more” in the context of well-lit 24/7 consumerism.”