In the UK, frequent questions about street lighting design involve the type of street lighting to use (e.g., LEDs, HPS), the impact on wildlife, and how to minimise energy consumption. These and other more common questions asked are listed below:-
- What are the most common source types of street lighting?
The most common types of source for street lighting are LED’s. LEDs are known for their energy efficiency and long lifespan, however if lighting is not designed correctly by a competent person then their concentrated light can cause glare and potentially harm nocturnal wildlife. Before the rise in popularity of LED’s High-pressure sodium (HPS) lights were the most popular option, but are being phased out by asset owners as they are not as energy-efficient as LEDs.
- Can artificial lighting effect wildlife?
Many ecologists across the United Kingdom have concerns about the effect of street lighting on wildlife, especially nocturnal creatures like bats. Choosing warm white colour temperatures and ensuring lights are shielded to minimize glare are important steps in mitigating this impact. Along with ensuring that street lighting is designed by a competent person.
- How can street lighting be more energy efficiency?
Questions around minimising energy consumption and the costs associated with different lighting systems are common. For many local authorities across the United Kingdom a phased approach to replacing of existing lighting stock can help optimize energy usage and reduce long-term expenses. Installing lighting systems that are dimmed using a central management system or a smart type pre-set dimmed photocell can also help to reduce overall energy consumption.
- If I have an unadopted road, can I light it with low level illuminated bollards?
Low level illuminated bollards should generally be used for wayfinding purposes only. British Standards for Road Lighting and documents such as Secure by Design do not recommend using low level illuminated bollards for road lighting.
Lighting with low level illuminated bollards could see increased procurement, installation and ongoing maintenance costs, due to the increased number of bollards that would be required to meet the lighting standard for the road when compared to lighting with conventional lamp columns with road lighting luminaires.
- I have a planning condition which refers to street lighting, do I need a professional street lighting design?
Local authorities will sometimes apply planning conditions to approved planning applications. When there is a specific lighting condition that says plans should be provided along with reports and full details of proposed lighting for a site, it is very often a necessity to instruct a competent lighting consultancy to produce a drawing and lighting calculations which include isolux contours on your plans to demonstrate lighting output. Very often the local authority planners will be interested in the isolux contour values at the site boundary to ensure that there is no obtrusive light or light trespass that can cause issues to sensitive receptors.
- What Is an Environmental Zone?
Environmental Zones are set out in an easily accessible document called ‘The Reduction of Obtrusive Light’ which is produced by a well know body in the lighting industry called the Institution of Lighting Professionals. Environmental Zones are range from E0 up to E4, with E0 areas being protected areas such as designated Dark Skies areas and E4 areas being town/city centres. Generally, in the simplest of terms, higher Environmental Zones such as E4 zones are allowed to be lit to a greater lighting levels.
- Why do we need street or public lighting?
Public or street lighting is generally provided to ensure the safety and well-being of all residents. Roads and junctions are lit for the safety of all road users and is generally installed to try and reduce the frequency of road traffic accidents. A good lighting system will enable facial recognition of people using footpaths etc which helps to promote a sense of safety and in turn wellbeing.
- What is photometric data?
Photometric data is inserted into industry standard lighting design software, and it simulates the light output from a specific luminaire that the file relates to. Each luminaire in a range will have a specific photometric file and a different light footprint or output. It can confirm brightness, intensity, evenness of light and more. Photometric data allows lighting designers to know if the light output from a specified luminaire is adequate for a lighting fitting to be used for the illumination of a road/footpath or other types of areas that they may be lighting.
- Why do street lighting luminaires have an IP rating?
Street lighting luminaires are exposed to rain, snow, dust, and other elements. An adequate Ingress Protection otherwise known as IP rating ensures the luminaire’s electrical components and internal wiring are shielded from moisture and debris, preventing short circuits, damage, and potential hazards. IP ratings are a fundamental aspect of street lighting design, ensuring the safety, performance, and durability of these essential fixtures in diverse outdoor environments.
- What’s the difference between lighting with a flood light and a Street lighting Luminaire?
Street lighting luminaires are generally used in areas where lighting is required to be distributed in a controlled manner, on sites where perhaps there are sensitive local receptors such as close by houses or areas where ecology may be affected by artificial light. Floodlighting luminaires, as the name suggests, generally flood lighting into a specific area and have less control over the light output. At MMA we generally use less floodlighting fittings these days and opt for a more accurate street lighting luminaire that can put lighting down where it is required as appose to scattering light in many directions.
- What is a Maintenance Factor?
When carrying out street lighting design calculations, we apply a Maintenance Factor as a correction factor. The correction factor takes into account the depreciation of the lamp lumen output over time and the build-up of dirt on the luminaire.
- What is a DNO?
A Distribution Network Operator is a company licensed to distribute electricity in the UK. These companies own and operate the system of cables and towers that bring electricity from the national transmission network to homes and to items of street furniture. In a high percentage of cases street lighting columns owned by the local authorities across the country have DNO electricity cables, these are fed off a mains DNO low voltage cable normally running in the highway.
- What is a Charge Code?
A Charge code is a 13 digit number assigned to apparatus that UMS Customers wish to add to their inventories. Charge codes are used within the UMSO systems to calculate volumes of electricity consumed.
- What is a PCN – Private Cable Network?
Private Cable street lighting Networks can be designed for situations where DNO’s cannot supply mains cables across a given area. If a feeder pillar can be supplied at the edge of a development site for example, then a PCN can be designed to supply electricity to lamp columns on the site. Private cables can also be fed from DNO fed lamp columns to illuminated signs and bollards, some local authorities insist on this approach on their networks. We have an experienced team of designers who can carry out private cable lighting designs within street lighting projects.
- What does Correlated Colour Temperature mean?
Correlated Colour Temperature, abbreviated to ‘CCT’, refers to the measurement of a light source’s perceived colour, indicating whether it appears warm or cool. It’s measured in degrees Kelvin (K), where lower values signify warmer, yellowish light, and higher values indicate cooler, bluer light.
- What is the difference between a warm white and neutral white LED?
Warm white LEDs have a colour temperature typically around 2700K to 3000K, producing a warm, slightly yellowish glow. Neutral white LEDs, on the other hand, have a colour temperature around 4000K, offering a cleaner, more neutral white light without the yellow tint of warm white. When dealing with an ecologically sensitive site it is best, if the specifications allows, to use a warm white LED as they tend to be less harmful to species such as bats.