LED: sustainable, but above all maintenance-friendly

LED uses less energy, the bulbs last for longer and even the fittings have a longer lifespan. Within a decade, all external lighting on campus will be LED. This is expected to make a big difference in terms of maintenance.

The Kluyverpark in the southern part of the campus is the first location in which LED lighting is being used, in the lamp posts and ground spotlights. That started in 2015. The project was immediately used as a pilot to see which fittings are suitable. In the process attention was also paid to the electrotechnical aspects, in other words the electricity cables, voltages and the network load. The latter, in particular, caused a number of teething problems. For example, LED lighting uses more power when switched on and consequently causes a higher peak load on the power network, thereby activating the security mechanism in the power supply cabinets. The solution was to reduce the number of LED light fittings and lower the inrush current in the power supply cabinet. Solving the puzzle provided input for the further technical development required for the introduction of LED lighting across the rest of the campus. 

After the pilot had been completed a schedule of requirements was drawn up, as well as a technical manual showing how the LED lights had to be installed, up to the power cable. This paved the way for the broad use of LED lighting on the campus and it is now being used in lampposts at an increasing number of locations. 

Advantages of LED

Conventional lights have to be replaced after two to five years. In theory, a LED light source should last as long as the fitting, around 20 to 25 years. A lamppost lasts for around 40 to 50 years. The expectation is that the lamp and the light fitting will only have to be replaced once during the lamppost's lifespan. 

A further benefit of LED lighting is the possibility of controlling it remotely using software, for example to monitor electricity consumption, to make it easy to increase or decrease brightness, or to change the colour of the lighting. 

Consequently LED not only saves energy, but also offers a social and sustainable solution in the form of a safer environment. Normally the campus is illuminated up to 5 lux but with LED there is enough capacity for 10 lux. As a result the light level can be adjusted as needed, for example in the case of events attended by a large number of visitors. In late 2018 dynamic dimming (dimming based on need) was introduced for the public lighting.

LED ambition

TU Delft's ambition is to replace all conventional lighting with LED lighting in the coming ten years. During any major reconstruction projects on campus everything will be converted. One example is the redevelopment of the public space in the Stevin Area behind the CEG faculty, where all the lampposts were converted to LED lighting. The expectation is that 75% of the conventional lighting can be replaced in three to four years. The rest will be replaced in the last six to seven years.