Month: September 2019

Categories Blog

Understanding Consumers and Their Sockets

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 The lighting industry has never been more alive.  The business is evolving faster with new opportunities and technologies every day and in my new role as the global CEO of the lamps business at OSRAM, I have the privilege of leading our journey into this exciting future.  The sweeping, dynamic innovation of the lighting industry is challenging how we do business from product development to consumer and customer engagement. That is why it has never been more important to understand what consumers know – and don’t know – about LED lighting technology.

Recently, we released the results of this year’s edition of the OSRAM SYLVANIA Socket Survey, a report that examines consumer awareness, adoption and understanding of lighting technology. Now in its seventh year, the survey has evolved from initially helping us understand how aware and prepared consumers were for the phase out of incandescent bulbs to current research more heavily focused on LED lighting and smart, connected lighting technology.

I am pleased to report that consumer adoption of LEDs is on the rise as 65 percent of Americans surveyed have purchased LEDs for use in their homes and the majority (64 percent) of those who did, purchased LED bulbs for use in sockets. Of the respondents who were identified as LED bulb users, the most valued benefits of making the switch were reduced energy consumption (96%), longer bulb lifespan (93%) and cost savings (93%).  As the price of LED lighting continues to come down, what was perhaps a prohibitive barrier is beginning to be perceived as a value, with 86 percent of Americans who have purchased LEDs believing the initial cost was worth it.  Consumers like what they’re seeing, which underscores how important it is for us to continue delivering quality LED products to the market.

 

From FitBit to Nest, the Internet of Things continues to take the world by storm, and the lighting industry is no different. Smart lighting is the next big frontier and awareness of this technology is high at 62 percent of those surveyed.  However, we’re still very early in the adoption cycle, with only one in 10 reporting they have purchased smart lighting products. Fortunately, consumers who are interested in the smart, connected home understand the role and value that lighting can provide, as 83 percent of those surveyed believe that smart lighting is a good introduction to home automation technologies.

There are certainly areas of opportunity for improvement, and consumer education is always a priority. Though we’ve seen great progress with virtually all survey participants (99%) aware of LED lighting versus only 69 percent in 2012, consumers’ top sources of information about lighting products continue to be in-store displays, retail employees and product packaging. Our industry’s evolution certainly isn’t slowing down, which makes educating consumers all the more important to continue today.  By partnering closely with the retail industry, we can work to ensure that purchasing decisions around lighting are as informed as possible.

The future will continue to bring new and exciting innovation, not only in technology but also in our understanding of how lighting impacts our productivity, health and well-being. Today, consumers recognize poor lighting when they see it, but they can’t necessarily articulate what makes for ‘good’ or ‘appropriate’ illumination. Imagine a world where we won’t need to think about our lighting at all because it will adapt to our behavior, the task at hand, the time of day and the setting. As we continue to inject software-fueled intelligence into our lighting systems, it’s clear that future has arrived.

Halfway into what the United Nations has named the International Year of Light, the Socket Survey shows that we’re making positive progress and guides us to where work still needs to be done.   Looking ahead, I can’t help but feel confident about where we are and where we are going.

Categories Blog

Seeing is Believing

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Congregations are realizing they have a responsibility to set an example and be stewards of the earth. While environmental stewardship may be implemented in a variety of programs such as purchasing eco-friendly cleaning supplies, planting an organic flower and vegetable garden on the grounds, and recycling, the opportunity with the largest potential impact on the bottom line is energy conservation.

There are approximately 350,000 houses of worship in the United States. Energy use represents the greatest negative environmental impact of the average house of worship.[1] Greenfaith, an interfaith coalition for the environment, believes it’s time for communities of faith to become leaders in the fight against climate change through energy conservation – saving valuable funds to invest in religious activity and outreach.

According to the US Environmental Protection Agency, congregations collectively spend close to $2 billion on energy annually and energy costs are the second highest fixed cost after personnel. But energy use, specifically lighting, is a way to reduce costs. Tremendous advances in technology and engineering make it possible to achieve a significant reduction in energy use and expenditures. Most congregations can cut utility costs by up to 30 percent through strategic investment in energy efficiency.[2]

If America’s houses of worship reduced their energy usage by just 10 percent:

  • Nearly $200 million could be saved
  • More than 5.4 billion in kWh would be available without additional cost or pollution
  • More than 2 million tons of greenhouse gas emissions would be prevented [3]

Religious Organizations Take the Lead
Numerous religious organizations are in the forefront of energy conservation. For example, Interfaith Power and Light (IPL), is an organization that began in California in 1998 whose mission is “to help churches become good stewards of the earth.” To become a member, churches must sign a covenant and pledge to “green” their congregations through various means. Churches who sign IPL’s covenant gain access to resources like a professional energy audit, and support to make changes that can add up to lower bills, less energy waste and a more informed congregation.

The Sustainable Sanctuary Coalition “assists faith groups to preach, teach, model and advocate for sustainable living and ecological justice for all creation. The group works to extend a helping hand to congregations of all denominations that are interested in going green but don’t know where to start.”

Another example is Philadelphia’s Interfaith Coalition on Energy, comprised of the city’s Archdiocese, Board of Rabbis and the Metropolitan Christian Council. The organization’s mission is to inspire congregations to reduce the costs of operating their facilities by guiding them to use measurably less energy and to purchase energy at lower cost.

In a 2008 survey by the National Association of Temple Administrators, nearly 95 percent of Reform (Judaism) congregations in North America have investigated or initiated some form of greening their facilities; and of those that have engaged in major construction recently, 64 percent attempted to use sustainable materials.

The General Convention of the Episcopal Church passed a resolution in 1997 calling on members to practice energy efficiency in response to climate change concerns. Leaders in the Church established Episcopal Power and Light to combine the purchasing power of churches and their congregations to buy green power. The aim was to unite communities, empower congregations, and build bridges among different religions with the goal of reducing the threat of climate change. The US National Council of Churches, with about 340,000 congregations, and the World Council of Churches are developing similar programs.

These are just a few of the many faith-based organizations leading the drive to reduce congregations’ energy consumption and expenses.

The Calling
Demand for sustainable houses of worship is being driven on multiple fronts. The need for healthier environments, the role that religious institutions should play to lead this charge, and the ever increasing energy prices, coupled with a challenging economy, has grabbed the attention of congregations’ clergy and lay leaders. But certainly not all 350,000 congregations are looking to build new, sustainable facilities; many are in need of smaller-scale ways to reduce energy costs.

Typically, lighting can account for a large portion of a congregation’s electricity cost. This means that significant cost savings can be achieved with energy-efficient improvements, and due to continually improving technology, lighting usually provides the highest return-on-investment of major upgrades.[4]

Parking Lot Illumination
One key to making day-to-day operations more energy efficient and more sustainable is through the installation of exterior LED luminaires. Most congregations have parking lots that require illumination and use traditional parking lot lights that consume a staggering 22.2 billion kilowatt-hours per year.[5] Parking lot energy needs could be reduced by more than 40 percent, and maintenance costs could potentially be cut by more than 80 percent with the installation of LED lighting, according to the US Department of Energy.

[1] www.greenfaith.org “Energy Conservation.”
[2] National Council of Churches’ “Bottom Line Ministries that Matter.”
[3] “Congregations: An Overview of Energy Use and Energy Efficiency Opportunities,” Environmental Protection Agency, NationalServiceCenter for Environmental Publications.
[4] Energy Star®: “Putting Energy ito Stewardship, Congregation Guide.” December 2007
[5] Facilities Engineering Journal, March/April 2009 issue, page 34, “Parking Lot Lighting System Saves Energy.”

Categories LED

LED Warranty Protection – Buyers Beware of the Fine Print

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What is in a warranty? Most buyers of commercial products expect that the manufacturers will stand by their technology and replace it if there is failure.  For LED lighting, the LED warranties are not a promise to save money through energy reduction. LED warranties are a promise that the lights will perform at levels that buyers expect. The key warranty questions in the growing LED marketplace are what defines LED fixture failure, what triggers a replacement, and how long is the coverage.  Buyers should proactively ask these questions to the manufacturers or the suppliers and ask to review the actual warranty language as part of the assessment process in choosing LED fixtures.

The majority of commercial LED light manufacturers around the world offer 5 Year LED Warranties to meet the minimum requirements of the DesignLights Consortium (DLC) for its Qualified Products List (QPL). The minimum protection along with other criteria serves as the guide for most utility companies to approve rebate eligibility. One of the problems with the DLC warranty criteria is that it only requires the 5 years and does not get into the details of what is covered. This creates a potential false sense of security for buyers. With tens of thousands of applications and listed LED products, DLC does not have the resources to review the qualitative details of the LED warranties. So, buyers need to take the initiative to assess the value of the protection themselves.

The few manufacturers that offer a 10 year LED warranty often have “fine print” with limitations on daily hours of operations, carve-outs outs for lesser protection on the LED drivers, or restrictions on warranty transfer if the original owner sells the building or business. Buyers beware, because many LED warranties also define “failure” with surprisingly high percentages of diodes, and they do not include protections against color shift or total output degradation relative to L70 standards.

Beneficiaries of a Strong LED Warranty:

PROPERTY OWNERS: A 10 Year LED Warranty benefits owners and managers of facilities that have areas with 24 x 7 illumination such as office building emergency stairs, hospitals, hotels, parking garages, fire and rescue centers, dormitories, and any emergency egress lighting for facilities such as schools.

SERVICE and FINANCING PROVIDERS: A 10 Year LED Warranty benefits Energy Service Provider Companies (ESCOs), commercial lighting solutions providers, and companies providing Saving Share or Lighting as a Service (LaaS) programs.

For performance contracts, the service providers are often obligated to keep the lights on. So, a longer warranty and more reliable products help reduce their maintenance and replacement costs. Plus, as financing plans for energy saving lighting become increasingly popular, many lenders are requiring warranties that do not have the “fine print,” giving the manufacturers a way out of replacing failed technology. Naturally, lenders also desire LED warranty coverage to match their financing terms. So, if the terms are extended to roll-in solar or HVAC on a facility, a strong and long LED warranty for the lights is favorable. 

Watch out for the Drivers:

Over the past two years, some LED companies were confident enough in the longevity of their diodes that they started offering 10 year LED warranty coverage on their LED fixtures, given in-field and laboratory testing. However, the warranties sometimes included limits of up to 60,000 hours on the external driver (6.84 years at 24 x 7 operations of 8,760 hours per year).  The drivers were the “Achilles heel” of the systems. Recently, some LED manufacturers have started offering 10 Year LED warranty protection on complete diode and driver systems, in part because external drivers with “potting” help insulate against damaging heat gain.

Categories LED

LED High Bay Luminaires – Ready for Prime Time

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High bay lighting is the most common type of lighting used in commercial facilities that have high ceilings and require high foot-candle levels. They are ideally suited for warehouses, cold storage, airport concourses, grocery stores, gymnasiums, convention centers and other large indoor spaces with mounting heights between 15 and 40 feet, and ambient temperatures between -4°F and 131°F.  While high bay lights have traditionally used high intensity discharge (HID), metal halide (MH) or florescent lamps, many specifiers and facility managers are changing to LED luminaires. 

Properly designed and engineered LED-based high bay luminaires can offer big advantages for commercial applications. However, it’s important to consider LED luminaires that take a systems-level approach that includes driver design and thermal management, rather than just retrofitting LED “bulbs” into existing fixtures.  Thermal management is critically important to achieve the reliability expected from LED luminaires.  Extreme temperatures, both hot and cold, are common in high bay environments and can have a negative impact on the performance of electrical components.

Compelling LED Lamp Life 

  • 50,000 hours or better (5 years or more)
  • Minimizes the cumbersome maintenance of high ceiling applications

Advantages of LED Technology

  • Exceeding government mandated efficiency standards
  • Controlled distribution of light for enhanced uniformity
  • Higher luminaire efficacy

Let’s examine in more detail the many advantages of LED technology for high bay fixtures and a few application examples.

Warehouse Lighting
According to the Department of Energy, lighting uses as much as 29 percent of the electricity generated in the US and for industrial facilities, traditional lighting:

  • Uses 38 percent of the energy in a typical warehouse
  • Requires 15 percent of the energy in a refrigerated warehouse
  • Consumes 75 percent of a warehouse facility’s energy expenditures when maintenance is factored in with energy costs

Here’s where LED luminaires’ dramatic energy efficiency really makes an impact, particularly because many facilities that illuminate with high bays are in operation 18 to 24 hours a day. Typically, lighting is viewed as a fixed expense, but it shouldn’t be; energy costs can be dramatically reduced, up to 75 percent, and maintenance can be virtually eliminated through the installation of LED luminaires. Additionally, paired with occupancy sensors and/or dimmable components they provide even greater energy efficiency.

Further power savings are achieved from turning off the fixtures when not in use. Workers often leave the traditional lights on continuously because they take so long to warm up to full brightness. LED luminaires light immediately, eliminating the need to have them on all the time.

Many LED retrofit installations don’t require a one-to-one replacement so the combination of using fewer fixtures for shorter periods of time provides a lower energy bill and significantly reduced maintenance expense.

Cold Storage Lighting
With large, open spaces to cool, as well as sizable lighting requirements, cold storage facilities can consume vast amounts of energy.  As in any business, owners and managers of cold storage warehouses are often faced with minimizing their operating costs.  The energy used by the refrigeration system is often a major contributor to this cost of operation.

Conventional lighting and refrigeration systems typically work against each other.  Lighting systems generate heat, which the refrigeration system needs to remove.  In addition, lower temperatures typically reduce the efficacy of lighting systems.  Therefore, more power is required to generate the desired illumination, which in turn, increases the load on the refrigeration system.

Facilities can save tens of thousands of dollars in yearly electric costs, and cut harmful emissions by thousands of tons by implementing a handful of simple, cost-effective efficiency measures to reduce electrical consumption and have a payback period of three years or less such as installing LED luminaires. [1]

Only certain technologies, such as LED luminaires, are capable of functioning for cold storage needs at temperatures that range from zero degrees to -40°C.

Gymnasium Lighting
For years, the standard method of lighting gymnasiums has been the 400 W MH high bay.  This has led to gyms with deteriorating light levels and poor playing conditions that are expensive to operate. The MH system is essentially an “on-off” system that provides little control over light levels.  Also, these lights require 10 minutes or more before they reach their full light level.  After they are turned off, they require a similar amount of time before they can be turned back on again.  As a result, these lights are typically turned on in the morning and kept on until the building closes, regardless of whether there are any activities in the gym.  Additionally, MH use a lot of energy but produce less light as they age, giving gyms and other facilities poor illumination.

LED high bay luminaires deliver instant white light with no restrike or run-up delay.

LED Lamp Life
Correctly designed LED will not fail catastrophically, but rather slowly dim. LED luminaires are determined to have “failed” when light output reaches 70 percent of original output. In fact, well designed fixtures can last over 50,000 hours making non-scheduled equipment downtime due to lamp failure nonexistent.

How long is 50,000 hours?
Based on the length a fixture is illuminated per day, here is what a 50,000 lifetime translates into on an annual basis:

Hours of Operation –  50,000 hours is:
24 hours a day 5.7 years
18 hours per day 7.6 years
12 hours per day 11.4 years
8 hours per day           17.1 years

With LED luminaires, maintenance costs are minimized as relamping may not be required during usable lifetime of the product. Another important consideration given that high bays are ceiling-mounted and may need the use of a lift to change out the burned fixture.

LED Illumination – Ready for Prime Time
Debate continues about whether LEDs have the output in lumens. Through advancements in technology and manufacturing, bright white LED luminaires for commercial lighting applications are in the market. Recent legislation in the US has led to the phase-out of mercury vapor ballasts and lamps as well as 150 to 500 watt MH luminaires. LED technology fills these needs, while far exceeding government mandated efficiency standards.

A LED luminaire incorporates an array of point sources that direct light precisely where it’s needed, with very little scattering or loss. Light distribution is controlled by the placement of LEDs, as well as by efficient use of optics that take advantage of the focal point presented by each individual LED.

Since traditional lamps are high-intensity near-point sources, the optical design for these luminaires causes the area directly below the luminaire to have a much higher illuminance than areas farther away from the luminaire. In contrast, the smaller, multiple point-source and directional characteristics of LEDs can allow better control of the distribution, with a resulting visible improvement in uniformity.

LED luminaires use different optics than traditional lamps because each LED is, in effect, an individual point source. Effective luminaire design exploiting the directional nature of LED light emission can translate to lower optical losses, and higher luminaire efficacy.

Categories Lighting

The March of Mid-Power LEDs into General Lighting

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The research firm IHS just released a 2014 forecast for the LED general lighting market, which indicated that mid-power LEDs would represent >80 percent of the LED units shipped and roughly 48 percent of the revenue.  This is quite a change from a few years ago where revenue of high power LEDs dominated the general LED lighting market. There are numerous factors that have driven this shift including improved LED efficacy, adoption of lower cost plastic packaging, and a shift from magnetic transformers to mechanical approaches to achieve safety isolation.  This is especially true in integral bulbs and as a result the LED string voltage is no longer limited to 30 to 60 V depending on the regional safety requirements.

In some cases mid-power LEDs are a combination of several low power LEDs in series in a single package.  As a result, high voltage mid-power low current LEDs are available with typical forward voltages ranging from 9 to 100 V. One impact of using these LEDs is that alternate driver topologies instead of the classical isolated flyback can be used that result in lower electronics cost and/or higher power conversion efficiency.

 

Figure 1. Single LED string direct AC drive operation

One of the simplest direct AC approaches involves a bridge rectifier, constant current regulator (CCR) and a string of LEDs as seen in Figure 1. If the LED string voltage is sufficiently high compared to the input AC voltage, the losses in the CCR can be kept to a reasonable level while achieving > 0.9 power factor.  This approach does have lower LED utilization since for a portion of the AC cycle, no current flows through the LEDs as seen by the red line.  In this example there is no electrolytic capacitor in the circuit for energy storage so this type of driver results in 100 percent optical flicker at 100 / 120 Hz (2x the AC line frequency) but the driver circuit is simple, small and can have a long operating life time.   As it is not always practical to match the LED string voltage to the AC line voltage a switching topology is needed.

To better understand how to determine the right switching topology based on the string voltage, we wanted to compare several mainstream topologies and provide some general guidelines to help designers understand how the selection of the LED string voltage impacted the topology choice.  To do this a figure of merit (FOM) was created that combined the maximum voltage stress and peak current through the power switch as a function of the LED forward voltage and the input line voltage.  This FOM is a good proxy for both efficiency and cost in a switching LED driver as the lower the peak current, the lower the losses in the switch, inductor and diodes.

Two general use scenarios were considered. First, applications where high power factor and low THD (<20 percent) were required and the second where high power factor is not required.  As an example for ENERGY STAR LED lamps, there is no power factor requirement for lamps < 5 W and in the EU there is a special input line harmonic exception in EN61000-3-2 for lighting products < 25 W so high power factor is not required.  An added benefit of not needing high power factor is that it is easy to achieve low optical flicker.

The buck, buck-boost, boost and isolated flyback with a turn’s ratio of 3 were all compared based on the FOM (the lower the better) as a function of the VF to Vin peak ratio.  In the case of the high power factor case, the total harmonic distortion was limited to < 20 percent for analysis and we assumed a 600 V MOSFET (80 percent derating).  For VF/Vin ratios from 20 to 40 percent, the power factor corrected buck is the best topology. The upper limitation of the buck is related to THD and power factor and not stress on the power switch.  Interestingly it turns out the best topology from the FOM analysis is the boost, which is not the first topology to come to mind for many designers.  An example of a complete high PF 10 W boost design is shown in this design note where a 220 V LED string was driven at 30 mA across an input voltage of 90 to 135 Vac.

 

Figure 2. Topology comparison for high power factor >0.9

 

 

Figure 3. Topology comparison for low power factor (EN61000-3-2 Class C Exception)

 

When looking at applications were it is not critical to achieve high power factor, the clear winner for strings of higher voltage LEDs is the buck topology as seen in Figure 3 as it has the best FOM across a wide range of forward voltages.  An added benefit of this approach is that it is one of the simplest to implement and can have low optical flicker. The reason that the curve ends below 70 percent is due to meeting the requirements of the EN61000-3-2 Class C exception where the input capacitor is undersized to control the input current shape. For applications in the US market where compliance to EN61000-3-2 Class C is not required, this range can be extended. An example of a complete 3.8W buck design is shown in this design note where a 150 V LED string was driven at 25 mA across an input voltage of 200 to 265 Vac and achieved 85 percent efficiency.

This FOM comparison is a good reference tool at the beginning of the LED selection and architecture definition.  In some cases, especially at more narrow VF/Vin, there are several options that should be considered since the differences between different topologies is relatively small but in many cases this can give clear guidance in what topology is best for lowest system cost and better efficiency.