• • • LIGHTING • • •


THE GROWING ROLE OF RETROFIT IN EXTERIOR LIGHTING UPGRADES:


WHAT ENGINEERS NEED TO CONSIDER


BY TIM BARKER, MANAGING DIRECTOR, ACROSPIRE


F


or many years, exterior lighting upgrade programmes have followed the same approach: replace older lanterns with new


LED fittings. Whether upgrading legacy HID installations or early LEDs, full lantern replacement became the industry norm. Today, however, that default is increasingly


being challenged. Rising material costs, shrinking capital budgets and growing sustainability commitments are prompting asset owners to take a closer look at their existing infrastructure. Rather than automatically replacing ageing lanterns, engineers are increasingly being asked whether existing assets can be upgraded through retrofit solutions that extend service life while delivering modern performance.


Why is retrofit receiving attention The first large-scale LED lighting programmes were delivered more than a decade ago. While many achieved major energy savings at the time, significant numbers of legacy HID lanterns and early-generation LED installations remain in service across the UK. For engineers responsible for maintaining these


assets, both HID installations and first-generation LED schemes present their own challenges, particularly around maintenance, performance and component obsolescence. Drivers are reaching end-of-life, control systems


are becoming unsupported and replacement components can be difficult to source. Advances in LED performance, optics and controls mean many older installations no longer deliver the efficiency or functionality expected of modern lighting systems. Improvements in LED efficacy over the last


decade mean energy savings of up to 35 per cent may be achievable compared with first-generation


30 ELECTRICAL ENGINEERING • JUNE 2026


LED systems, further strengthening the case for retrofit. In many cases, the lantern housing remains


structurally sound, creating an opportunity to upgrade internal components while retaining the existing asset.


The engineering benefits The main benefit of a retrofit is commonly seen as cost reduction, but the engineering case is broader than simple capital savings. Retaining a serviceable lantern can reduce


material consumption, minimise waste and lower embodied carbon associated with replacement projects. It can also support circular economy objectives by extending the useful life of existing assets. For engineers responsible for long-term asset


management, the result is a more balanced asset management strategy, where investment is targeted at components that have reached end-of-life rather than replacing entire assemblies unnecessarily.


Evaluating retrofit suitability Retrofit is not suitable for every installation. Although the benefits can be significant, engineers should review the existing asset before deciding on the most appropriate upgrade strategy. The physical condition of the lantern remains


the starting point. Existing housings should be inspected for corrosion, mechanical damage and signs of degradation that could affect long-term reliability or safety. If the structural condition of the asset is compromised, replacement may prove the more practical option. Thermal performance also requires careful


consideration. Modern LED systems rely on effective heat dissipation to achieve their


expected service life and performance. An existing lantern housing originally designed around lamped technologies may not always provide the thermal characteristics required by contemporary LED components. Engineers must also consider whether the


upgraded lantern can meet current lighting requirements. Lighting standards, road classifications and user expectations may have evolved since the original installation was specified. Any retrofit solution should be capable of meeting current photometric and operational requirements. Electrical compatibility is equally important.


Existing wiring arrangements, surge protection measures and control systems should be reviewed to ensure they can support modern drivers, sensors and connectivity requirements. Long-term maintainability should also form part


of the decision-making process. A retrofit should not simply resolve today’s problem. Engineers should consider component availability, future support arrangements and the ease with which the upgraded asset can be maintained throughout the remainder of its service life.


Installation and


programme advantages Retrofit can also deliver practical benefits during project delivery. Because the existing lantern body and mounting


arrangements are retained, installation times can often be significantly shorter than full replacement schemes. On one recent project, installation time per lantern was under 8 minutes, minimising disruption and traffic management costs.


https://acrospire.co electricalengineeringmagazine.co.uk


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