Lighting is as essential to civilized society as clear air and clean water. In the absence of sunlight, artificial light allows us to carry on doing everything we’d do during the day - even things like motor racing, skiing, and golf. But not without some impact. The U.S. Energy Information Administration estimated lighting in the country consumed 211 billion kilowatt hours of electricity in 2021. That's about five percent of America’s total electricity generation. The percentages are similar across the developed and developing world.
Generating that much electricity, even with an ever-increasing proportion of renewable power (from wind, solar and hydroelectric sources), results in a significant ecological footprint. Lighting accounts for 5 percent of worldwide greenhouse gas emissions, according to the U.S. Department of Energy (DOE). That’s around 2.5 billion tonnes of carbon dioxide equivalent (CO2e).
But it used to be much worse. The glowing filament of traditional incandescent bulbs turned only around five percent of the electrical energy powering them into light. That meant a lot of electricity had to be generated, only to be wasted as heat, to provide sufficient illumination for people to go about their business. Now things are changing thanks to semiconductors: both in the form of solid-state LED lighting and through the power-efficient intelligence of Bluetooth Low Energy (Bluetooth LE) SoCs.
LEDs generate light through the physical phenomenon of electroluminescence. Electroluminescence is generated by applying a voltage across a p-n semiconductor junction because electrons recombine with electron “holes” in the semiconductor and emit photons in the process. So-called white light LEDs were first commercialized by Japanese company Nichia in 1996, and market forces have resulted in ever-improving efficiency.
Today, LEDs use about 15 percent of the energy of an incandescent bulb to generate the same amount of light and last up to 30 times longer. LEDs also push out the relatively efficient “energy-saving” compact fluorescent lights that once enjoyed the largest market share.
Analyst Statista says that by 2020, over 50 percent of the global lighting market was served by LEDs, heading for 75 percent by 2025 and nearly 90 percent by 2030. While adoption is already significantly impacting carbon emissions, the U.S. DOE says a wholesale shift to LEDs could reduce CO2e emissions by 800 million tonnes per year, the equivalent of shutting down 684 coal-fired power stations. That's a big step towards sustainability.
But even better efficiency can be gained by making LEDs smart through wireless connectivity. Connectivity allows automation of actions such as dimming lights when external conditions are brighter or cutting illumination when people leave the room. The savings are even better when the wireless controllers are themselves optimized for the lowest power consumption.
This is why U.S. smart lighting and building solutions company, Acuity Brands, chose Nordic's Bluetooth LE SoCs for its smart lighting controllers. The company estimates that pairing Nordic's ultra-low power technology with solid-state lighting has saved over 2.3 million tonnes of CO2e emissions from six million of its smart lighting deployments in the five years from 2016 to 2021. The CO2e emission reduction is based on a calculation of lower fossil fuel-generated energy consumption of the new Acuity lights compared with the energy consumption of the previous lighting solutions.
Acuity says the Nordic Bluetooth LE SoCs played a critical role in reducing the power consumption of its smart luminaire lighting fixtures by 40 watts while they’re in use. “Sustainability requires every single joule of energy to be conserved …and Nordic wrote the book on energy-efficient short-range wireless chips. The [company’s] SoCs allowed us to maximize [carbon] savings,” said Adam Handler, Director of Corporate Sustainability at Acuity Brands.
Smart lights can do more than save energy. Connected lighting forming a wireless mesh network can become a building-wide grid gathering a lot of data which in turn can inform smart decisions. For example, building managers can use the information to lower operating costs, decrease maintenance, and even support advanced services such as asset tracking and indoor navigation.
Szymon Slupik, CTO and founder of lighting control company and Nordic customer, Silvair, told the Bluetooth SIG that the value of additional services enabled by smart lighting is seven to ten times more valuable than the lighting controls and energy savings themselves.
We, humans, want to do many things after the sun goes down and artificial light allows that to happen. Connected, high-efficiency LEDs not only mean we can do so more sustainably but also gain new benefits that go far beyond just illumination.
This article was first published on Nordic's Get Connected Blog.