Shedding new light on LED lighting’s benefits
LED lighting is an easy way for many building owners to cut down on energy bills and reduce potential maintenance and safety costs
Each year the United States spends about $200 billion just to power commercial buildings and another $200 billion to power industrial facilities. The Better Buildings Challenge, which was launched in 2011 as part of the Obama Administration's commitment to creating clean energy jobs and lowering energy bills for businesses, aims to help America's commercial and industrial buildings become at least 20% more efficient over the next decade.
Lighting is one of easiest and fastest payback routes to energy savings and, to help achieve the Better Buildings target, taking an informed and strategic approach to facility lighting—which can result in millions of dollars of lost revenue each year—and its control is more important than ever.
Not only could plant engineers and facilities managers realize real energy and maintenance cost savings and help to reduce site CO2 emissions, but they could also improve safety, security, and employee comfort.
Lighting the way
With around two thirds of today’s lighting still based on older, energy-wasting technologies developed before 1970, it is not surprising that lighting currently accounts for 19% of global electricity production, according to the International Energy Agency (IEA). However, a full switch to the latest energy-efficient light emitting diode (LED) lighting, combined with smart control and management systems, could provide very significant energy savings of up to 80% in many applications.
The first practical visible-spectrum LED was invented in 1962 by Nick Holonyak, a scientist at General Electric. Today, his invention is truly revolutionizing the energy efficiency of lighting. In fact, worldwide, the switch to LED lighting could save energy consumption for lighting by 40% and reduce carbon emissions by 670 million tons, the equivalent output of about 640 medium sized power plants. If such a switch occurs, it is estimated that over two thirds of the benefit could be achieved in the commercial and industrial sectors.
The benefits of LED lighting
LED lighting brings countless benefits to industry; helping to transform not only working environments, but also business performance. The key benefits of LED lighting include:
- Energy efficiency: The key benefit for LED adoption is energy efficiency—it can help cut operational costs by up to 80%. Achieving the lighting levels required for a particular application at the lowest possible energy input becomes critical as energy costs rise and as government regulations clamp down on wasteful energy sources.
- Long life and low maintenance: LEDs can last for up to 100,000 hours and, because they are rugged and long-running, maintenance and lamp replacement costs are also much lower.
- Reduced carbon impact: LEDs can help facilities meet their sustainability targets by significantly reducing carbon emissions.
- Non-toxic: LED lighting is the only non-incandescent lighting source that contains no mercury. This eliminates any chance for mercury to escape into the environment either in operation or after disposal.
- Resistant to shock, vibration, and corrosion: LEDs can be used in environments where other technologies fail.
- Cold start capable: LEDs provide instant on and instant restrike capabilities with no warm-up time required to achieve full brightness.
While the benefits are undeniable, to ensure optimum energy efficiency, reliability, and durability, LED lighting needs the support of specialist control gear called LED drivers from specialist manufacturers.
Drivers: What you need to know
LED drivers play an important role in the overall design of lighting by delivering the correct voltage and current to the LED. At their simplest, drivers take the input current and input voltage and then reconfigure them for use by an LED. In that sense, they are a lot like the ballasts used for decades in fluorescent lights.
While drivers are key in enabling market growth for LEDs in several ways—innovations in design are allowing products to do more with less by improving the overall efficiency—there is no such thing as a “universal” LED driver, and the quality of the driver has a significant effect on the performance of the LED.
The type of LED driver required is determined by a range of factors, including the type of LEDs being installed, the number of LEDs being installed, whether they will be placed individually or in series strings, whether there are size limitations, and ultimately, what the main design goal of the installation is.
There are two main types of driver available today—constant current and constant voltage—which come in a number of variations. In simple terms, constant current drivers tend to be used when one driver is required per light fitting. The current will remain the same, whatever the number of LEDs in the fixture. Constant voltage drivers are best for applications where the user requires flexibility with the number of luminaires connected to one power supply. As lamps are added, the current will increase to the maximum limit.
With the overall design goal in mind, another important lighting concept is the availability of dimming functions. With dimmable drivers, LEDs can be controlled to a suitable level for the application, whether to create a certain ambience or to highlight certain features. In addition, dimmable drivers allow for further energy savings to be achieved as they work on the premise that the human eye struggles to distinguish between LED lights that are on at 100% and those that are on at 90%.
LEDs can usually be dimmed between 100% and 0% using a number of different methods, including analog. Analog 0-10V drivers offer a basic dimming solution. They can be programmed with a passive controller or a fixed variable resistor. These controls use voltage input to manage the intensity of the light. For example, at 10V, lights would be on at 100%, at 5V, lights would be powered at 50%, and at 0V, lights would be off.
The bottom line is that, in addition to their capacity to slash energy bills and avoid greenhouse gas emissions, flexible LED lighting solutions are infinitely scalable, extremely reliable, and have a much longer lifetime than almost all other types of lighting. Combined with efficient and controllable drivers, LED lighting technology can create a compelling value proposition in the illumination of industrial installations.
Antony Corrie is vice president at Harvard Engineering Americas, which designs, develops and manufactures electronic HID ballasts, LED drivers, and control products for the lighting industry.