Times may be tough, but a new lighting scheme rather than a simple retrofit should pay dividends beyond simply cutting your electricity bills. Dave Tilley explains

Few would disagree that the retail sector is going through a tough period and the new and used car market has been hit harder than most.

During difficult times, it will always be tempting to cut maintenance and service regimes, but this could be a false economy as competition intensifies, and it could lead to disaster.

The following case study demonstrates how new lighting technology has transformed a Mercedes car showroom, improving the energy efficiency and reducing maintenance requirements, but enhancing the brand image and the customer’s sales experience.

Tired old installation

The original showroom lighting was typical of an installation that was about 15 years old. Fluorescent sources supplied the ambient light and the display lighting consisted of low voltage lamps. The yellowing prismatic panels on the fluorescents and the ageing low voltage downlights did little to promote the upmarket image central to Mercedes.

Before – new lighting would boost energy efficiency and brand image

Before – new lighting would boost energy efficiency and brand image

The original lighting installation consisted of:

  • 33 4 x 36W switchstart recessed modular with prismatic sheet and
  • 59 50W MR16 low voltage downlights.

Annual energy consumption: 34,600kW, responsible for emissions of 19.17 tonnes of carbon dioxide.

If the object of the refurbishment was to keep costs down, it would be a simple matter to replace the fluorescents with retrofit T5 lamps with new prismatic panels and use 30W IRC MR16 lamps rather than the old MR16s in the downlights. For such a scheme:

Annual energy consumption: 12,600kW, responsible for emissions of 6.98 tonnes of carbon dioxide.

Other considerations

This approach, however, would be overlooking the important business considerations of sales and brand image.

The replacement lighting scheme that has been installed at the showroom has two important design features:

  • There is no ambient lighting.
  • There are separate day and night circuits.

The omission of ambient lighting means the display lighting can be focused without compromising the average light level. While the overall effect is not as uniform – which is what many designers would strive to achieve – the focus is now on the cars, drawing the attention of potential customers.

The day and night circuit makes it possible for the showroom to have a low level of light during the evening – the products are visible and security is improved.

The luminaires in the new installation are:

  • 56 70W CMH adjustable downlights and
  • two 26W decorative pendants.

Annual energy consumption: 15,900kW, responsible for emissions of 8.81 tonnes of carbon dioxide.

Return on investment

The table demonstrates the differing times to achieve return on investment for the simple retrofit scheme and the chosen, completely new, installation.

To choose between the two schemes, the client must consider the importance the business places on the sales experience and its image. In these difficult times, the decision is not an easy one, but the lighting system can be as important to a business as marketing and staff training.

The CMH option was chosen. Not only does the new lighting installation cut annual energy consumption by more than half, it also has a number of other benefits for the client:

Increased focus on the products; Improved light quality and colour rendering; Lower maintenance costs; Better customer sales experience; and Enhanced brand awareness and image.

The lighting scheme also highlights service areas and information points, helping customers find their way around the showroom.

The efficiency of the luminaries, greater than 90 per cent light output ratio, meant that a balanced number of luminaries could be installed and let the client apply for an Enhanced Capital Allowance. The overall efficiency of the new scheme also made it possible to secure an interest-free loan from the Carbon Trust.

Difficult to quantify

With the exception of maintenance costs, it is difficult to quantify the other benefits to the client. Even quantifying maintenance costs can be difficult – different methods of accounting and the use of in- house and external maintenance providers can make identifying the true cost an estimate at best.


The installation of a new lighting scheme that supports the sales process and enhances image is essential to the development and growth of a retail business, regardless of the sector.
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