Networked lighting systems and HAVC help save energy

There is still untapped potential for energy savings from networked lighting controls (NLC). This is the conclusion of a study by the DesignLights Consortium (DLC), which also recommends reviewing energy efficiency incentive models in order to exploit the full benefits of controlled lighting.

The consortium defines NLC as the combination of sensors, network interfaces and controllers that make lighting changes, but does not include the luminaires themselves. NLC systems can be wireless, with radios embedded in the devices connected to each other, or with wires connecting the control components of the network.

The DLC points out that although previous research has shown that installing NLCs with LED lighting designs can increase potential lighting savings by 50% on average and also offer a number of non-energy related benefits, NLCs are installed in less than 1% of commercial lighting systems in the United States, for example.

“First-generation LED systems are reaching the end of their useful life, and replacements for second-generation LED systems are being planned in offices, industrial buildings and other commercial facilities across the country, so it’s important to understand the energy-saving potential of NLCs in a world where decarbonization is a priority,” says Christina Halfpenny, executive director and CEO of the DLC.

The DLC study presents the technical and economic potential of NLC systems for lighting commercial and industrial buildings by 2030 and how public services and programs should encourage connected lighting.

Citing the case of the United States, the report shows that the country estimates that LEDs will account for 88% of all lighting systems installed in commercial buildings by 2030 – in 2017, the proportion was around 26% – but that only 14% of lighting systems will be connected and controlled. This is a possibly optimistic projection. In addition, previous DLC research has shown that, although the energy savings provided by NLC are expected to total 34 terawatt hours (TWh) by 2035, aggressive promotion of this type of system could double that figure.

Obstacles to wider adoption

Reasons for the delay in adopting NLCs are varied, says the DLC report, but one important barrier is concern about the initial cost of installations and the return on investment. What makes it difficult to understand the true economic benefits of NLCs comes from the fact that, although some evaluations of the energy efficiency saved by NLCs are accurate, almost none consider the possible energy savings brought about by integrating lighting with other building systems, such as heating, ventilation and air conditioning (HVAC).

Much of the energy savings could be achieved by using occupancy sensors in lighting systems to reduce the energy consumption of HVACs in unoccupied spaces.

Conclusions from a survey of facilities in the US states of Arizona and Connecticut evaluating integration with HVAC systems were particularly convincing, reports the consortium. The research revealed that the savings associated with HVAC justify the potential energy savings from lighting, especially for large office and retail facilities, healthcare and other buildings that are major energy consumers. Without the savings from HVAC systems, the savings from lighting alone would not be financially justified.

The energy efficiency potential associated with NLCs is significant. In the most optimistic scenario, the study found reductions in electricity consumption in commercial buildings in 2030 of almost 10% in Connecticut and 5% in Arizona. In addition, the study found that NLCs could reduce peak demand in 2030 by 1.8% in Connecticut and 0.7% in Arizona, while integration with HVAC systems could reduce natural gas consumption in 2030 by 1.3% and 0.5% in Connecticut and Arizona, respectively.

we need to change the paradigms that encourage first-year results and short-term objectives. Supporting the adoption of integrated NLC systems will also require customized incentive programs, technical assistance and customer education.