Quantity

More is better! Because each step in the remanufacturing process incurs fixed costs, remanufacturing or reusing more products will spread costs out better.

Materials

Valuable and high-carbon materials will make it more economically and environmentally worthwhile to reuse or remanufacture products. For example, it's often perceived that higher quality products containing aluminium housings retain their value due because of the cost and longeivity of the material as well as its continued function in cooling LED light sources.

Variety

If the project has lots of different luminaires, or even "similar-but-different" luminaires, that could make it very difficult to reuse the luminaires in another site, or for a remanufacturer to work with them. This is because what might seem like minor differences could prevent economies of scale, requiring each 'type' of product to be treated in a different way.

Condition

If products are in as-new condition, then great! However, products in deteriorating condition can pose a challenge for remanufacturing or reuse, where components may need to be carefully assessed and processed to reach an acceptable condition. Consider things like the ageing of plastic (exposure to UV or heating can cause plastics to discolour and become brittle, which can cause mechanical, aesthetic and optical problems), rusting or corrosion which can weaken luminaires mechanically (and aesthetically!) by consuming metal, ageing of plastics or foams in seals which can lead to ingress, ageing of electrical components and especially cable insulation which can lead to risk of electric shock if not addressed.

Building and customer constraints

Site opening hours, access restrictions, operational constraints and other factors relating to building type, age and function are all important to consider when developing a plan for remanufacturing or reusing luminaires.

Legislation changes

If the products are of an older construction, laws and standards may have changed since the products were designed. This can mean it's difficult to place the product back on the market and also applies to unused products coming direct from warehouses or excess stock. While this might rule out reuse, remanufacture can be a great strategy for upgrading products or changing specifications - not just returning to original condition! Wherever there are legal or safety concerns, it's essential to take professional advice from an insured remanufacturer.

Size and bulk

Bigger and heavier makes it harder to transport, however, may indicate that the material and carbon savings of reuse would be greater

construction

The product design has a large impact on circularity. Some things to look out for:

• Adhesives

  These can make it really difficult to take products apart and replace components. Remanufacturers might risk damaging products or have to use chemicals to overcome adhesives, which can be time-consuming, laborious and thus costly.

• Snap-fits, push-fits, rivets

  These features are great for single-use products, but are sometimes difficult to disassemble and in the case of plastic snap-fits, are prone to breaking.

• Deteriorated plastics

  These can pose a significant difficulty for remanufacturers, both to identify specific materials used and to ensure the materials are in suitable condition to be put back into use. Repairs on plastics, adressing faults like cracks or stripped threads are possible but are not commonly used in the lighting sector due to their complexity and the often low-value of these components.

• Material safety challenges

  Older products may contain unsafe materials within components, such as mercury, lead, POPs. These materials may require specialist waste processing and treatment, which can incur additional care and costs. Presence of hazardous materials may require additional risk assessment and pose complexity when ensuring compliance in placing products onto the market. As well as electronics and lamps, enclosures can also pose challenges, as for example GFRP parts can pose a hazard to users and remanufacturers - plastic degredation can release dangerous glass fibres that can be irritating to skin and lungs.

• Weight and size

  Larger and heavier luminaires can be more difficult to reuse and remanufacture simply because they are more difficult to de-install, transport and remanufacture without damage and incur greater transport, storage and packaging costs.

• Bespoke products

  Products which are niche, specialist or bespoke (for example, a specific mounting dimension to fit the ceiling grid in a particular building) are harder to reuse in other premesis and remanufacturers may have less experience with them, however, this may not pose an issue for remanufacturing to return to the same site

• Product labelling and documentation

  Where manufacturers have clearly labelled products with key technical information, and where details documentation and even construction or disassembly information is made freely accessible online, or documentation is held by the product owner, this can support remanufacturers in determining feasibility of remanufacturing products.

Change of technology

It's great to upgrade products designed for older lighting technologies like fluorescent lamps to LED technology, but there's a lot to consider and it's not always practical and safety is key. Consult a remanufacturer for advise.

Consider the lighting task!

The reuse/remanufacture project needs to ensure the quality of light and other functionality like emergency lighting, controls and IP ratings match the specifications required.

Application requirements

Projects with specific requirements like sector or market specific approvals, military standards or similar may add testing and certification costs and challenges for the remanufacturer to navigate

Purchaser requirements

Procurement practices can both help and hinder circularity initiatives. Larger customers tend to put in place processes which help them to ensure the products and services they procure meet quality, cost-effectiveness and other requirements. Mechanisms like frameworks can also help customers tender work effectively to trusted suppliers while reducing approval overheads. However - these mechanisms can sometimes promote circular or sustainable products or services through scoring metrics, or present a barrier if mechanisms are set up with "business as usual" procurement channels in mind, or make it challenging for smaller organisations to propose circular services.

In-use emissions

Luminaires use electricity to generate light and their annual energy demand depends on how frequently they are on, their brightness (lumen output) and energy efficiency. Products using older lighting technologies like fluorescent tubes or fluorescent bulbs are still in common use across the world, and these are therefore particularly urgent to upgrade to newer light sources; using circular economy approaches can avoid waste when doing so.

It's worth comparing embodied carbon emissions with estimated operational carbon (i.e. in-use emissions, or annual energy use). It's common for 90%+ of lifetime emissions to be operational, meaning that while material waste and embodied carbon are important, energy efficiency is often the primary environmental consideration for luminaires.

Lighting design

Lighting products are selected and used to create a lighting effect in their use environment. The appropriate selection of brightness, optical properties and colour temperature for a particular environment is just as important as focussing on product energy efficiency alone. If light is not properly directed, it can be wasted, whether generated efficiently or not.

Controls and sensors

There are a plethora of lighting controls and sensors available to lighting designers, engineers and remanufacturers. These can assist the user in dimming or switching lights off when ambient light is adequate or when rooms are unoccupied. However, user experience, cost, product interoperability and the embodied carbon of control equipment should all be considered.

Wireless lighting controls are often proprietary and software obsolescence or server shutdowns can pose a risk to users. Interoperability challenges are a significant challenge for reuse of lighting controls, however there are now a number of protocols which aim to support device interoperability which will encourage the reuse of such equipment.

Selecting luminaires and brands

Specifiers and luminaire designers are faced with tradeoff decisions when striving for greater sustainability. More robust and less integrated product design has a good history of encouraging stakeholders to maintain and remanufacture products, however these products are likely to incur more embodied carbon to start with. Lighter products designed with plastics are harder to reuse, remanufacture and also properly recycle, but feature lower embodied carbon emissions to begin with.

There are some general principles to consider:

• Consider buying reputable brands with a track record for good quality and for supporting users with spare parts and even remanufacturing services. But be cautious - bigger brands are not always better!
• Consider that the greater detail a brand can supply regarding product construction, circular options and environmental considerations, the more thoroughly they have considered their product design and service offering. Greenwashing can often be easy to spot with simple questions.
• If it's possible to determine the region that products were manufactured in, your embodied carbon estimate will show that this makes a modest difference to carbon, depending on the amount of renewable energy in the manufacturing country. Products manufactured closer to their point of use also reduce transport emissions, but data shows this is typically not a key hotspot.
• Common or tried-and-trusted product styles are more likely to be supported by the broader remanufacturing sector, who may be familiar with these products over highly bespoke models. If in doubt, obtain a sample and investigate
• Product longevity, quality and length of warranty are crucial, supporting both longer lifespans and indeed often correlating with better circularity opportunities.
• Reducing product variety, wherever possible, sets up the product portfolio for better servicing by remanufacturers.
• Luminaires which adapt well to change-of-use, such as track-mounted luminaires or which can be adjusted in terms of position, optical priperties, brightness and colour temperature are more likely to be reused within the same building or another, if changes occur to the lighting system.