Human-centric lighting boosts supermarket sales by 28%

THE INSTALLATION of human-centric lighting has boosted sales at a German supermarket by up to 28 per cent.

The influence of the human-centric lighting on the experience and behaviour of the customers was primarily determined via the atmosphere, mood and well-being while shopping.

The trial of the technology at an Edeka store in Lower Saxony saw total sales increase by 12 per cent compared to a nearby reference store, with confectionary sales rising by 28 per cent, fruit and vegetables by 26 per cent, wines and spirits by 23 per cent and pre-packaged meat by 23 per cent.

The scientific study, conducted over 10 months, also saw customer dwell times boosted by 21 per cent and employee absence tumble by 35 per cent.

The sensational results will provide tangible evidence to proponents of human-centric lighting can it can give clients a significant return on investment.

In the morning the lighting is a neutral-white colour temperature of 4000K with a horizontal illuminance of 700 lux. At midday and in the afternoon the colour temperature rises to a cool white 5000K and the illuminance to 1,000 lux horizontally.

Towards evening the horizontal illuminance drops to 600 lux and the colour temperature falls to a warm 3000K.

The phase shifts take place over a long period of time and are not directly perceptible for customers and employees. The progamme of changes is adapted to the seasonal course of the sun.

The settings were designed to have a positive effect on staff and customers by ‘activating’ them during the day and reducing daytime sleepiness, and ‘deactivating’ them in the evening, all using the lighting’s colour temperature and intensity.

In three waves, both employees and customers were surveyed in the two stores with regard to wellbeing, satisfaction and perception of the environment in the course of the day.

As well as the sales’ increase, the human-centric lighting had other positive effects including an improvement in sleep quality among employees.  Staff who  work mainly at the check-out counter at the reference store had, on average, a higher number of sickness-related days of absence in the first six months of the trial than employees in the same position at the human-centric lit store.

The number of sickness-related days of absence was reduced by more than 35 per cent given constant exposure to circadian lighting.

The influence of the human-centric lighting on the experience and behaviour of the customers was primarily determined by feedback about the atmosphere, mood and wellbeing while shopping.

The results show that the light in the human-centric lit supermarket is assessed as significantly more natural compared to the more artifocially perceived light in the reference store.

Customers appreciated the natural atmosphere of the lighting that simulates the natural course of the sun.

The programme was designed to have a positive effect on staff and customers by ‘activating’ them during the day and reducing daytime sleepiness, and ‘deactivating’ them in the evening, all using the lighting’s colour temperature and intensity.

To assess the shopping experience, customers were additionally asked the reason why they decided to shop at the respective supermarket.

The study found that 35 per cent of the customers decided in favour of shopping at the human-centric lit store because of the ‘special atmosphere’ and 23 per cent because of the ‘good service’.

This indicates that customers appreciate the lit environment and are therefore even willing to travel longer distances.

Moreover, the customers were asked to assess the mood or atmosphere in certain sections of the supermarkets.

It’s evident, say the researchers, that all sections asked about in the human-centric lit store were assessed more positively than in the reference store.

The biggest difference emerged in connection with the checkout counter section. There customers appreciate the circadian light control, which supplies the right light at every time of the day and thus neither appears too bright nor too dark nor too warm or too cold as compared to daylight.

Results regarding recommendation to others in the form of the net promoter score (NPS) show a generally very high customer satisfaction in both supermarkets.

Under human-centric lit conditions, however, the NPS of 99 per cent is considerably higher than the reference store of 82 per cent. Circadian light control here provides for higher customer satisfaction and recommendation rate. Well-being and satisfaction are also reflected in the time spent in the store by customers.

The lighting and control system was supplied by Cologne-based retail lighting specialist Oktalite.

The reference store also boasts high-quality LED lighting and is located 3 miles away. 

There’s no significant differences between the two supermarkets and both stores continued to be run by the same management with the same shift times and a similar clientele and range of products.



  • Guido Fox, head of export at Oktalite will discuss the remarkable findings of the Edeka trial of human-centric lighting at 5.05pm on Wednesday 14 November at the Lighting for Retail and Hospitality Conference track at LuxLive 2018. Entrance to the conference is free - see the full programme HERE. LuxLive 2018 takes place on Wednesday 14 November and Thursday 15 November 2018 at ExCeL London. Register for your free place HERE.


Comments 2

There is no mention in the article about the CRI of the "human-centric" lighting. CRI would have a greater impact on how enticing the produce and baked goods appeared than color temperature.

I'd call attention to the statement in the sidebar regarding 250 Lux in the eye. This is presented as some sort of established "fact" when it is really only a personal opinion of the author or someone else. In addition, it is simply wrong and uninformed by neuroscience. First of all, if you don't tie that intensity to a Spectral Power Distribution, then you have no idea what the blue content is of that light. Since it is the Blue light that contributes most significantly to melatonin suppression, the specification of a single Lux value is meaningless. Secondly, it is well known that the lens of the eye turns increasingly yellow with age, and that this serves as a retinal protection mechanism. So the amount of that 250 Lux of light hitting the front of the eye that actually gets into the eye is age dependent. The effects of that light will be more potent in younger people, and significantly less effective in older people and the elderly. Again, specifying an arbitrary Lux level is incorrect and meaningless.

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