Light Pollution Solutions: Choosing The Right Light Bulbs

Light pollution is a pressing issue that has harmful effects on wildlife, ecosystems, energy consumption, climate change, and human health. It is caused by the human-made alteration of outdoor light levels from those occurring naturally, and 99% of people in Europe and the United States live under light-polluted skies. To reduce light pollution, it is recommended to use covered bulbs that light up facing downwards, minimize the use of decorative lighting, and switch to energy-efficient light bulbs such as LED lights. Additionally, motion sensors, timers, and dimmers can help reduce average illumination levels and save energy.

Use motion sensors

Using motion sensors is an effective way to reduce light pollution, especially from street lights. Motion sensor street lights are smart devices mounted on street light poles that detect human movement and adjust the brightness of the luminaire accordingly. They are beneficial because they provide:

Energy Efficiency and Cost Savings:

Motion sensors ensure that street lights remain at low intensity, for example, at 20% brightness when the streets are vacant. Once a person enters the detection area, the sensor triggers the street light to brighten to a preset level, such as 80% or 100% intensity. This "right amount of light when and where needed" approach can lead to significant energy savings of up to 80% without compromising public safety and comfort.

Reduced Maintenance Costs:

By dimming the street lights when no one is around, motion sensors prolong the lifespan of the luminaires, resulting in reduced replacement costs and less frequent maintenance visits. Additionally, motion sensor smart street lighting systems provide remote diagnostics and automatic reporting, further reducing the need for manual inspections and maintenance equipment.

Improved Safety and Security:

Motion sensor street lights enhance safety by automatically illuminating areas with human or vehicle presence. The brightened pathways improve visibility for pedestrians and drivers, reducing the risk of accidents. Furthermore, the presence of motion-activated lighting can deter crime and make it more difficult for intruders to go unnoticed.

Reduced Light Pollution:

Motion sensor street lights play a crucial role in reducing light pollution. These smart lights automatically brighten only when a person is detected. When no one is around, they remain dimly lit, reducing sky glow and light pollution while also conserving energy. This reduction in light pollution helps protect the nocturnal ecosystem, including wildlife species that rely on natural light cycles for navigation and migration.

Climate Change Mitigation:

Street lights are typically powered by electricity generated from burning fossil fuels, a major source of greenhouse gas emissions. By implementing motion sensor street lights, cities and municipalities can significantly reduce their energy consumption and carbon footprint. This transition to on-demand lighting can be a substantial step towards more sustainable and environmentally friendly urban lighting solutions.

In summary, the use of motion sensors for street lighting offers a wide range of benefits, including energy efficiency, cost savings, improved safety, reduced light pollution, and a positive impact on the environment. By adopting this technology, communities can strike a balance between providing adequate lighting for public spaces and preserving the natural darkness of the night sky.

Use low-wattage, solar-powered lamps

Light pollution is a pressing issue, impacting wildlife, human health, and energy consumption. It is caused by inefficient and excessive lighting, particularly at night. To reduce light pollution, one strategy is to use low-wattage, solar-powered lamps. Here are some reasons why this approach is beneficial:

Energy Conservation and Cost Savings

Low-wattage, solar-powered lamps consume less energy compared to traditional lighting. This not only reduces energy bills but also contributes to environmental conservation by lowering carbon emissions. Solar-powered lamps harness energy from the sun, making them a renewable and cost-effective option.

Reducing Light Pollution's Impact on Wildlife

The excessive and improper use of lighting at night can have detrimental effects on wildlife. It can interfere with migratory patterns and breeding cycles, and natural behaviours of various species. By opting for low-wattage lamps, the intensity of artificial light is reduced, minimising the disruption caused to nocturnal animals.

Enhancing Stargazing and Astronomy

Light pollution obscures our view of the night sky, making it difficult to observe celestial bodies and constellations. By using low-wattage lamps, we reduce the amount of artificial light pollution, thereby enhancing stargazing experiences and astronomical observations. This allows us to reconnect with the natural beauty of the night sky.

Improving Human Health

Constant exposure to artificial lighting, especially at night, can interfere with human health. It can disrupt our sleep patterns and metabolism, affecting our overall well-being. Low-wattage lamps help mitigate this issue by reducing the intensity of light at night, promoting healthier sleep habits and potentially improving health outcomes.

Flexibility and Ease of Use

Solar-powered lamps offer flexibility in terms of placement as they are not dependent on a constant power source. They can be installed in remote locations or areas where electrical wiring is not feasible. Additionally, advancements in solar technology have made these lamps reliable and long-lasting, making them a convenient choice for outdoor lighting.

By adopting the use of low-wattage, solar-powered lamps, we can take a significant step towards reducing light pollution. This approach not only benefits the environment and wildlife but also enhances our connection to the natural world, improves human health, and promotes sustainable energy practices.

Use covered bulbs that light up facing downwards

Light pollution is a pressing issue that harms our environment, wildlife habitats, and our quality of life. It is caused by the human-made alteration of outdoor light levels from those occurring naturally and has several negative consequences. These include interfering with wildlife migratory and breeding patterns, wasting energy and contributing to greenhouse gas emissions, causing unsafe driving conditions due to glare, and disrupting human metabolism and sleep.

One effective way to reduce light pollution is to use covered bulbs that light up facing downwards. This is especially relevant for street lights and highway lighting. By using covered bulbs and directing the light downwards, we can prevent excessive illumination of the sky, which is a major contributor to light pollution.

• Use directional or shielded fixtures: Install lighting fixtures that are designed to point the light downwards, ensuring that the bulb is only visible from directly underneath. This will reduce the amount of light escaping upwards into the sky.
• Focus the light beams: Choose lighting fixtures that focus the light beams downward, rather than allowing the light to spread in all directions. This will ensure that the light is directed only where it is needed, reducing light pollution and increasing efficiency.
• Use motion sensors: Install motion sensors on your outdoor lights so that they only turn on when motion is detected. This will not only reduce light pollution but also save energy and increase security.
• Implement lighting zones: Advocate for lighting zones in your community, with different levels of brightness in rural and urban areas. This will help reduce overall light pollution levels and ensure that lighting is used efficiently and effectively.
• Advocate for policy changes: Talk to your local representatives and support Dark Sky initiatives. You can refer to resources from organizations like the International Dark-Sky Association (IDA) to learn about policy templates and guidelines that can help reduce light pollution in your community.
• Choose certified light fixtures: When replacing or installing new lights, look for the IDA Fixture Seal of Approval. This certification ensures that the lighting fixtures minimize glare, reduce light trespass, and don't contribute to light pollution of the night sky.

By implementing these measures, we can significantly reduce the impact of light pollution on our environment and our health, while still maintaining the safety and functionality provided by artificial lighting.

Use low-CCT LEDs

The use of low-CCT LEDs is recommended by the International Dark-Sky Association (IDA) to reduce light pollution. CCT stands for Correlated Colour Temperature and is a measure of the colour spectrum of a light source, with lower values producing warmer colours. The IDA suggests using LEDs with a CCT of less than 3000K to minimise blue emissions.

Blue light is an issue because it is scattered more than other colours by air molecules and aerosols, creating a diffuse glow that obscures the stars in the night sky. This is due to Rayleigh scattering, which is strongly wavelength-dependent, and Mie scattering, which is wavelength-independent. Blue light is also an issue because the human eye is particularly sensitive to it, and it can therefore disrupt sleep patterns and the production of melatonin.

The use of low-CCT LEDs can help to reduce the amount of blue light in the environment, minimising sky glow and reducing the impact on human health. However, there are some drawbacks to low-CCT lighting. It can be less effective at reducing minimum illuminance levels under mesopic viewing conditions, and it is also less efficacious, leading to higher capital and maintenance costs.

Despite these drawbacks, the use of low-CCT LEDs can be an effective way to reduce light pollution and its impact on human health and the environment. It is important to consider the trade-offs between light pollution, visual performance, personal preferences, ecological concerns, and economics when choosing the appropriate CCT for a lighting installation.

Use coloured lights

Using coloured lights is an effective way to reduce light pollution. While they are less effective at night, yellow, red, and amber lights can be used to reduce the negative impacts of light pollution. These colours are anti-glare and do not affect night-time vision, meaning they can be used for lighting at night without causing the same level of light pollution as white or blue lights.

The colour of light is measured in Kelvins (K) and the associated values are expressed as correlated colour temperature (CCT). The best colours in the spectrum to use outdoors are yellow, red, and amber, as mentioned above. These colours appear at the lower end of the CCT scale, with red and yellow having lower CCT values.

In contrast, the other end of the light spectrum has a "cool" colour appearance, with colours appearing as white or blue and represented by higher CCT values. These colours should generally be avoided for outdoor lighting, as they have a larger geographic reach and create more glare. Blue-rich white light sources increase glare and compromise human vision, especially as eyes age. They also adversely affect wildlife behaviour and reproduction, particularly in cities, which are often stopover points for migratory species.

The International Dark-Sky Association (IDA) recommends that only warm-appearing light sources be used for outdoor lighting. This includes low-pressure sodium (LPS) lights, high-pressure sodium (HPS) lights, and low-colour-temperature LEDs. "Warm" toned or filtered LEDs should have a CCT of 3000 K or lower, and an S/P ratio of 1.2 or lower, to minimise blue emission.

So, while coloured lights may be less effective at providing bright illumination, they can be a useful tool in reducing light pollution and its negative impacts on wildlife, human health, and energy consumption.

Frequently asked questions