"The CHRONOS project" by Ranald Robertson, HITRANS and Patrick McDougall, CEO Nexus Alpha Limited.

The Technology Strategy Board is a non-departmental public body promoting innovation through investment and spreading knowledge. At a time of continuing pressure on conventional funding sources, HITRANS were attracted to TSB as an alternative source of funding for a cutting-edge project that would be of particular benefit to its area of population density and hence ridership too low to command investment in conventional information systems.

It was Jenny Milne (now of JLM Consulting) who approached HITRANS having identified TSB as providing the necessary revenue stream. Having ensured that the benefits were locked in, HITRANS lined up funding partners ScotRail and Moray Council with support also from Stagecoach.

Currently, Mankind only consumes the equivalent of one-eleven-thousandth of the sun's energy that reaches Earth. However, you can't just take traditional real-time public information display signs if you are going to solar-power them using local panels. You have to think differently.

The first Nexus Alpha Low Power Systems (NALPS) solar powered sign application came on the bus side in the very cold early months of 2010 with cholesteric panels (a bit like electronic etch-a-sketch to identify services) and LEDs to identify how far away they were, but the cholesteric technology is quite constrained at very low temperatures.

Refinements now include LED lighting and a reworked brighter time-track which is soon to be applied by HITRANS at Aviemore to say how far away the bus is.

Once the technology had proved successful at Findhorn, the project was ready to tackle seven ScotRail stations on the Far North Line. Challenges (all solved during the project) included:

- solar panel capacity, where it proved necessary to have more powerful panels manufactured
- battery storage (this was increased after snow lay on top of panels for the month of December 2010)
- location of battery (where Nexus Alpha LPS had to go for a lockable box as a third-party ground box flooded)
- proving system availability by monitoring the systems 24/7 and battery levels.

Confidence in solar capability was proven - the daily power consumption just 2.2 watts and the battery ended most days fully charged. Confidence in GPRS communications was also demonstrated through signal monitoring. Obtaining data for the signs was much easier in the rail environment than the bus environment.

With no digging-up for cable-laying, it cost just £11k in installation charges at all seven stations, where they proved cheaper also to maintain, with zero environmental impact and the power of a single kettle capable of supporting 1,600 displays - this, including such refinements as triggering the REACT audible system for the visually impaired.

It was the Technology Strategy Board that had given NALPS the confidence to raise the profile of solar capability, and the market must now be grown in order to create a sustainable business giving local benefit.

Latest options are for LTN-LCD - a low power LCD system that requires no backlight in daytime and for the continued development of energy-efficient flip dots which need no power if the display remains unaltered - and thus, for 59 seconds of each minute consume no power (that 1 second of power required to change the time of the system).

New applications include an interactive tactile map and the possibility of an eye-level sign at open level crossings with a detector down the track to warn users of the crossing that a train is coming.

Most other installations have used solar power as just a top-up, but CHRONOS shows the full benefit of placing total reliance on its virtues.

Report and photographs by John Yellowlees.