Ripple control switching For switching of outdoor public lighting, communities have used ripple control for several decades, provided by the grid operators. Ripple control is being phased out and replaced by IoT solutions. This is cost-effective for switching. It is cost-effective because many lights are daisy-chained via their power conductors to a single switch in the distribution substation or street cabinet. One IoT box switches an entire neighbourhood.

Dimming systems Dimming has been a bigger challenge. For dimming, each and every lamp needs to be connected. Many dimming systems are or have been on the market, all failing trials on cost, reliability and ease-of-use. RF mesh, high-frequency PLC and cellular (2G/3G/IoT) systems have attempted to provide a solid business case for dimming, and all have failed. In fact, many have been prematurely removed. The CAPEX and OPEX of such systems are simply too high to offset the achieved energy reduction.

LED Failure to provide a business case has ironically partly been caused by the introduction of LED technology. The reduced energy consumption has simply made it more difficult for a dimming system to save electricity cost. Bidirectional monitoring has become obsolete due to the extreme reliability and longevity of LED. The LED’s and drivers are simply more reliable than the network monitoring them.

Energy cost LED lamp
A typical outdoor LED lamp generates 6000 lumen and uses 50 Watts to do so. The lamp burns approx 4000 hours per year and a typical dim profile provides 50% energy reduction. Over one full year and with a kWh price of 4-10 eurocents the dimming energy savings amount to 4-10 euros.

Business case DigitalTF DigitalTF provides the dim signal for free if already mounted for congestion management. Adding a SaaS service to operate the lights remotely is divided over all connected lamps. This increases the control cost slightly, but still provides a very solid business case. We have contact with a very large lighting company that already produces LED drivers with built-in DigitalTF.

Business case IoT It is obvious that any IoT solution with at least 8 euro/year cost for just the subscription will never create a positive business case. Alternatively mesh RF and HF PLC systems are being offered. Many customers have found these systems to be very vulnerable and maintenance-intensive. In fact, many have been prematurely removed.