Lighting in Design Q3 2024

Lighting and DC microgrids Henk Rotman from Tridonic provides an overview of essential considerations concerning DC currents. T he invention and commercialisation of the incandescent lamp at the end of the 19 th century triggered the rollout of the electricity

their infant stage, their use is expected to grow as we see more and more ‘Net Zero’ buildings coming up and the growth in ICT, like data centres, where DC usage is common. If we look at lighting, the main impact of DC operation is on the LED driver, where DC allows the driver to be more efficient (5% to 10%), straightforward, smaller, reliable, and cost effective. The lower costs of DC-operated drivers allow for the acceleration of dimmable drivers, enabling further energy savings through lighting controls. DC lighting operation is not completely new, as we already have the concept of ‘Power over Ethernet’ (PoE), where Ethernet cables (usually CAT 5) provide a common wiring platform for a low-voltage DC power grid. However, PoE never really took off, mainly due to the costs of required PoE network switches. To summarise and conclude : • Driven by changes in both supply and demand, we see a growing interest in DC. • A repeat of the ‘war of the currents’ is unlikely; we will see a co-existence of AC- and DC-grids or stand-alone DC microgrids. • Important drivers of DC-grids will be the ‘Race to Net Zero’ and growth in ICT. • The lighting industry should prepare itself for the change, especially the LED driver suppliers, allowing the industry to benefit from the increased efficiency and potential of further miniaturization. Enquiries: www.tridonic.com

grid. The need for a standardised electricity network caused the so-called ‘war of the currents’ between Alternating Current (AC), promoted by Nikola Tesla, and Direct Current (DC), promoted by Thomas Edison. AC won, with DC only used in niche applications like transport (trains and ships). Nowadays, the electricity grid is one of society’s most valuable assets and is one of the foundations of the economy. However, in recent years, the electricity landscape has changed on both the supply and demand side, with more and more electricity generated by renewables (solar, wind) and more and more electronic devices as electricity users. With both renewables and electronic devices (think computers, LED lighting and EV chargers) using DC, this has created a situation where DC is converted into AC and then back into DC to feed electronic devices, all leading to extra costs, points of failures and losses. While the above favours a DC-based electricity grid, a repeat of the war of the currents is unlikely. A more likely scenario is peaceful co-existence in ‘hybrid microgrids’, with AC loads powered via a regular AC network and DC loads powered by renewables. Alternatively, we will see DC microgrids, especially in areas too costly to electrify. We can also consider applications like street lighting or poultry lighting. Although DC micro grids are in

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LiD Q3 - 2024