Passion of the people – 1.7.4

A matter of energy consumption and climate change

Lighting accounts for 19% of all electricity generated worldwide and for 16% in the European Union. Four out of five parts of this is industrial and office lighting, retail lighting and street lighting. Only one out of five parts is the lighting we use for private households. This leads to immense light emissions: Today, the planet’s light emissions represent one percent of total emissions, and in numbers, nearly 250.000 gigawatt-hours of energy. This gigantic amount of energy could take you 80 times to the moon and back. Or, it could power 38 million vehicle miles. The careful use of artificial light can reduce direct energy consumption and the associated costs. Energy savings also reduce CO₂ emissions and thus help curb global warming and environmental pollution and degradation.

Outdoor lighting—a blessing turned into a curse

Globally, annual electricity consumption from outdoor lighting is estimated at 400 TWh, producing an estimated 200 million tons of CO2 per year. That is more than 0.5 percent of global CO2 emissions! Estimates and data regarding the energy consumption of outdoor lighting vary widely. However, it is a fact that extreme over-lighting was prevalent until very recently. Think of sports facilities, shopping malls, or car parks. When these sites are fully lit, too much artificial light is sent unused into the atmosphere, and energy is unnecessarily wasted.

Urban Sky Glow—A waste of our energy

For decades, we have been observing star after star disappearing from our sight, especially in metropolitan and sub-urban areas. The foggy light above an urban conglomerate is called “dome of light” or Urban Sky Glow. Vienna’s Sky Glow for instance represents 500 GWh per year. This amount of energy could supply 100,000 households per year with electricity. The costs amount to 100 million euros, and 100,000 tonnes of CO2 are generated due to cumulative urban light production here.

The age of the LED—boon or burden?

Around the turn of the millennium, the highly efficient LED lights were developed and further improved. LED technology has many advantages, such as precise light control, dimming capacity, spectrum modelling (various colour temperatures) and low energy consumption. But this energy efficiency encourages the wasteful and environmentally harmful use of artificial light. It leads to a paradox that we call “Rebound Effect”: Instead of generating the same amount of light with less energy thanks to LED and other inventions, more light is generated with the same amount of energy. Hence, we can observe that more and more light is now being generated for the same energy consumption.

Another problem, this time at source

Power generation also produces wastes that are harmful to the environment and human health, depending on the type of energy source and production process involved. For example, carbon dioxide and heavy metals (e.g. mercury) are emitted by coal-fired power stations, and radioactive waste is produced in nuclear power plants. Thus CO₂ and heavy metal emissions as well as radioactive waste are generated indirectly in the production, operation and disposal of all products needed to produce light. Heavy metals and radioactive waste are harmful environmental toxins, and excessive CO₂ in the atmosphere promotes the greenhouse effect, which accelerates global warming. Responsible and efficient lighting accordingly makes a valuable contribution to environmental and climate protection.

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Passion of the people

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City Lighting – Image by Life of Pix – Pexels

LED Street Lighting – Image by Wangwukong – Getty Images

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