When William Shakepeare wrote Love’s Labour’s Lost he would have used light from tallow candles at a cost (today) of £12,000 per million-lumen hours. The same amount of light from electric lamps now costs only £2! But today’s low-cost illumination still has a dark side. Globally, lighting consumes more electricity than is produced by either hydro or nuclear power and results in CO2 emissions equivalent to two thirds of the world’s cars.
A standard incandescent lamp may be much more efficient than a tallow candle, but it is far less efficient than a high-pressure sodium lamp. Were inefficient light sources to be replaced by the equivalent efficient ones, global lighting energy demand would be up to 40% less at a lower overall cost. Larger savings still could be realised through the intelligent use of controls, lighting levels and daylight. But achieving efficient lighting is not just a question of technology; it requires policies to transform current practice.
This book documents the broad range of policy measures to stimulate efficient lighting that have already been implemented around the world and suggests new ways these could be strengthened to prevent light’s labour’s from being lost.