Following a successful trial of an innovative LED rail carriage lighting technology from Marl International Ltd, Porterbrook Leasing Company estimates that the technology could not only save 20 million kWh, but also improve the ambiance and reduce maintenance costs.

The announcement follows the completion of a £140,000 trial contract of Marl Sci-Light technology, arranged by distributor EAO, in which a 3-car Class 323 unit was equipped with the electronically controlled lights as well as data monitoring equipment to enable performance and energy consumption to be evaluated in detail.

Marl Sci-Light technology takes advantage of the controllability of LED lighting technology to adjust and supplement carriage lighting as ambient lighting conditions change. A 17W Sci-Light fitting replaces a 36W or 40W tube.

Lighting is reduced to a minimum of 7W in daylight, ensuring that the carriage appears lit and welcoming to boarding passengers, and only turned on fully at night time or when the train enters a tunnel or other dark area. The trial is ongoing, but between February to May 2009, Porterbrook found that on average the lights normally drew between 15W and 21W (approximately a 40% to 60% saving).

Sci-Light relies on high speed sensors, and innovative control software using smart algorithms to eliminate spurious responses to temporary minor obstructions like trees, ensuring that passengers are unaware that the light level is being changed.

The potential energy saving is estimated as 2,000kWh per carriage or 20 million kWh across the network per year, if the technology is applied to all 10,000 rail carriages in use in the UK today. This equates to reducing CO2 emissions by 9200 tonnes and is equivalent to taking 3,300 cars off the road. The reductions in maintenance costs enhance the financial appeal of the technology.