Categories Lamp

ENERGY STAR Lamp Standard Update

At the end of August, the EPA released the final version of the ENERGY STAR Lamps v1.0 Specification. This for the first time harmonizes the requirements for energy efficient compact fluorescent (CFL) and LED Lamps into one overarching set of requirements.While the ENERGY STAR lamp standards are voluntary, many retailers view compliance as a mark of excellence and the purchasing arms of US Federal agencies are required to purchase products that meet the standards.


Moreover, this is usually the benchmark that utilities use for eligibility to rebate programs so it is a force on the market for energy efficient lighting. For the LED lighting community, this new standard will supersede the existing Integral LED Lamps v1.4 specification when the new v1.0 standard goes into effect September 30, 2014. In my May article, I described in detail some of the key differences between the old v1.4 standard and at the time draft specification as it applied to LED lamps. To manufacturers, a more relevant milestone will be May 30, 2014 as this is when the lamp certifications bodies must stop certifying new products to the existing v1.4 specification. The table below summarizes the some key parameters between the old and new standard.


Standardization is a time consuming process and there is always vigorous interchange between the interested constituencies such as manufacturers, utilities, energy conservation groups, government agencies and retailers to come up with an acceptable balance. This standard was no different, especially since there were quite a few differences between how the CFL and LED lamps programs had approached technical requirements, in fact the first public discussions on this standard started in March 2011. On the LED front, some may be disappointed with the results in areas such as energy conservation, since the lumen efficacy bar at the lower wattage levels have only raised by ~ 10 percent and in fact for omni-directional lamps in the 10 to 15 W range, no improvement in efficacy is required over the old standard. This is an acknowledgement that initial purchase price is a bigger barrier to LED adoption than total energy consumption over lifetime. In other areas, clear progress has been made.

Dimmablity is not a requirement for LED bulbs but for the first time, there is now a minimal set of performance requirements for bulbs labeled as dimmable. In this case, a bulb must be dimmable to at least 20 percent lumen output and be tested with at least five dimmers from two manufacturers and be tested with 1 and 4 lamps in the circuit. While this is a far cry from the typical behavior of incandescent and halogen, it is a first step. Also in the dimming area, the standard does provide an alternate performance criteria based on the released at the end of April 2013, National Electrical Manufacturers Association (NEMA) SSL7A dimmer/lamp interface standard. A good tutorial on SSL7A can be found here. While less visible than ENERGY STAR in the market, the SSL7A standard should have significant long term implications as it defines a common interface definition between new dimmers and lamps that come on the market. So as NEMA SSL7A compliant lamps and dimmers enter the market, lighting architects, installers, and consumers will be able to have better confidence of purchasing dimmable lamps that meet some set of minimal criteria. None of these standards ensure incandescent equivalent dimming behavior so performance testing at the consumer/specifier level to separate the good from the best-of-breed products is still required and bulbs from different vendors installed on the same circuit can respond differently as they are dimmed but at least the industry is moving in the right direction. One requirement that was removed from the final v1.0 specification was a maximum limit for the flicker index of dimmable bulbs. Instead for manufacturers, the only requirement in this area at this time is to report the flicker index as part of the qualification reporting. This could be viewed as a first step to gathering flicker index performance on a large set of bulbs so that in the future it might be possible to establish objective thresholds on this parameter which is still being studied.

In the next 12 months, manufacturers will have their hands full preparing for the effective date of this new bulb standard. Fortunately in many areas, the changes are not a dramatic shift but more of a minor course correction. Going forward though future versions of this standard will no doubt be expanded to improve dimming criteria as well as incorporate new products such as Smart Wireless controlled bulbs as well as Zhaga compliant Light Engines that are coming on the market and are expected to reach broader adoption.

Categories LED

New ENERGY STAR SSL Requirements Ensure LED Bulbs Delight the Customer

On September 30th 2014, “ENERGY STAR Program Requirements Product Specification for Lamps (Light Bulbs)” will replace the “Integral LED Lamps Version 1.4”. To complete the analysis we started last time, we should look at dimming requirements in the new document, described in section 12, pages 19 and 20. Anyone familiar with designing dimmable LED bulbs and drivers is aware of the challenges that result from the availability of huge volumes of dimmers with very different performance in the market, and the significant trade-offs necessary to ensure the most widespread compatibility with all the different types of TRIAC dimmers. However, ENERGY STAR has limited the compatibility requirements to only five different dimmers from at least two manufacturers.

The new document recommends that different dimmer technologies (leading-edge/trailing edge or non-phase-cut types) be included in the test – but does not require it. Vendors will seek to make their offerings more attractive by increasing the scope of this test and adding additional compatible dimmer types on their websites or in the fine print on the bulb packaging.

So what does the dimmer compatibility test call for?

  • Dimming Performance (12)
    • Maximum Light Output (12.1)
    • Minimum Light Output (12.2)
    • Flicker (12.3)
    • Audible Noise (12.4)

ENERGY STAR does not mandate dimmability for all bulb designs, only those bulbs intended and marked for dimming applications.

Maximum light output requires that light output must be >80 percent of non-dimmer-connected level when connected to a dimmer. Many phase-cut dimmers, even at their maximum brightness setting, still limit the conduction angle to 160° or less, so this test ensures that the bulb will typically not be significantly less bright until the user begins to operate the dimmer switch.

Minimum light output describes how low the lamp brightness can be and sets a default requirement of greater than 5:1 dimming ratio (the manufacturer can publish a different number if they choose). Given that the minimum conduction angle of some dimmers can be in the range of 40°, turning the lamp off completely during dimming is often a challenge and the requirements of this test recognize that. An audible noise test is also required at minimum light output.

Flicker. The light needs to be on or the light needs to be off, any toggling between these two states creates the problem of flicker (variations in brightness rather than distinct on-off is typically termed “shimmer”). ENERGY STAR does not describe flicker as a pass-fail, rather it seeks to describe the amount of variation in light output that occurs (effectively shimmer and flicker). The measurement is flicker index, defined as the ratio of the light output curve above the average to the area below the average.

It should be noted that this is very different from the oft used term Percentage flicker (which is not used for ENERGY STAR)

Flicker index takes into account Duty-Cycle and wave shape. Because it is an area calculation rather than a peak-to-peak calculation, comparing flicker index and percentage flicker is a non-trivial exercise, even with the mostly sinusoidal waveforms exhibited by the majority of single-stage LED driver bulbs on the market today.

Audible noise is a consistent concern with LED drivers – especially when a step voltage is applied to the input of the driver by a phase-cut dimmer (worst at 90° conduction angle). ENERGY STAR calls for an audible noise measurement of less than 24 dBA at 1 meter from the lamp (or lamps – up to four must be tested together). Magnetostriction in the input filter- differential EMI inductors and ceramic input capacitors, can be a significant cause of audible noise. The problem is often exacerbated by the use of flexible packaging materials or insulating wraps that can act as sounding boards in a confined bulb design, greatly amplifying audible noise. Consumers are typically very sensitive to any kind of buzzing from LED lamps and the low amplitude of acceptable audible noise called for by ENERGY STAR (24 dBA is pretty much imperceptible to the average human ear) reflects this.

In conclusion, ENERGY STAR goes a long way towards promoting good practice in bulb design in a lot of areas, some of which are not immediately obvious to the end-user.

It is worth noting that since I wrote the first part of this piece, there have been moves in the US Congress to remove funding from the program of EPA enforcement of lamp efficiency standards – the de-facto incandescent bulb ban, which is, in itself, the major driver behind the increasing market penetration of LED lighting. (

Meanwhile in California…..
The California Energy Commission launched Title 20 and Title 24, state guidelines for LED bulbs and fixtures, on November 1st 2013. Like ENERGY STAR, this document is not a standard and is not technically mandatory, but to be eligible for the LED lighting subsidies offered by the California power utilities, a bulb or fixture has to meet the requirement. At the time of writing, Cree are the beneficiaries of a hefty $10.00 in-store rebate (dropping the price of their high CRI 60 W bulb to just less than $10) courtesy of PG&E. This is a game-changing 50 percent ASP reduction so the pressure will be on for all North American LED bulb makers to meet the requirements of Title 20. So how does it stack-up against ENERGY STAR in terms of requirements?. We will look to explore these requirements and discuss their implications for lighting designers for the whole North American market next time.

Categories Lighting

Lighting Controls: Decisions, Decisions

So we’ve made the decision…..we’re converting the parking deck to LED lighting.  Considering the money saved on the energy bill, along with the lower maintenance costs accompanied with not putting someone on a bucket truck for the next 10 years to swap out a bulb, it was an easy call.  Now the difficult question; do we also add controls to optimize the lighting system?  And if we do want controls, where do we begin? What will work for our parking deck?                   

Do We Need Controls?
The first question might not be whether or not we want to implement lighting controls, but whether or not we need to implement them.  Depending on the location, the state or municipality may very well require basic lighting controls to meet ASHRAE 90.1 requirements (or Title 24 compliance in California).  The overall intent of these standards is to ensure that, as a society, we are minimizing unnecessary energy expenditures, as determined by these governing bodies.  The goal is to reduce energy consumption per capita, which is often achieved through regulation.  The first step is to know whether we’re actually required to have a control system.  Keep in mind, this broad range of standards covers retrofits as well as new construction.

Do We Want Controls?
The next thing we have to ask ourselves is whether we want controls to manage our lighting system and to what degree.  In our world of high technology, embedded systems, and mobile devices, we have a plethora of choices to make when deciding exactly how we want our lights controlled.  When evaluating lighting control systems, they fall into two categories: Sensor Networks and Services.

Sensor Networks
Sensor networks deploy strategies for minimizing our energy bill, namely occupancy detection and daylight harvesting.  Nothing new here, but the decision-making comes into play in how sophisticated or intelligent we want that sensor network to be. Basically, our options are as follows:

System A: One-Way Communication

  1. A car enters the parking lot, tripping an occupancy sensor
  2. Sensor sends a control signal to a group of luminaires, declaring occupancy in the space
  3. Luminaires increase light output to safely illuminate the occupant’s path
  4. Occupant exits the area, causing the sensor to enter a state of non-occupancy, dimming the lights accordingly

In this scenario, the only system feedback we receive is a reduction in our energy bill.  But if our budget is tight, and we simply want to enjoy enhanced energy savings while complying with regulations, this approach will do.  If we desire more information from our system, then we’ll want System B.

System B: Two-Way Communication

  1. A car enters the parking lot, tripping an occupancy sensor
    – Sensor records and timestamps the event
  2. Sensor sends a control signal to a group of luminaires, declaring occupancy in the space
    – Luminaire(s) sends acknowledgement to the sensor that the message was received
  3. Luminaires increase light output to safely illuminate the occupant’s path
    – Light output measured and recorded
  4. Occupant exits the area, causing the sensor to enter a state of non-occupancy, dimming the lights accordingly
    – Sensor records and timestamps when system moved back into non-occupancy state
    – Occupancy events, power consumption, occupancy duration, etc. tracked and sent to central control unit for data processing

From the occupant’s perspective, System B’s functionality is identical to that of System A.  The value of the data is to us, as the owner, because we now have metrics telling us whether our investment is operating as intended.  We can also determine traffic patterns from the system data, including when the parking lot is being used, and how much energy the lights are consuming.  Using this basic information, we can further configure our system to minimize energy consumption, while ensuring the space is safely and securely illuminated for our patrons.

Whether we choose a one-way or two-way (data feedback) communication network, we need to consider the protocol.  Essentially, the protocol a system utilizes is the language executed to communicate between devices (sensors, controllers, light fixtures, etc.).  We have two protocol choices; 1) an open protocol (e.g. DALI, ZigBee, etc.), which allows devices from multiple manufacturers to communicate on the same network, or 2) a proprietary protocol, which is typically exclusive to a single manufacturer.  A network using an open-protocol is attractive from a competitive price standpoint because we have multiple controls vendors from which to choose.  The advantage of a proprietary protocol is that each device on the network was designed and tested to be compatible, so we can be confident in the communication and performance of the system.  Since a proprietary system is from a single manufacturer, we only have one phone call to make if we experience a system malfunction.

This is where lighting gets fun.  The lighting industry is experiencing a renaissance as it comes to grips with a convergence of technologies beginning with the LED.  LED luminaires present two distinct advantages over traditional lamp options:  1) the light source is a semiconductor, which provides for easier integration into embedded systems, and 2) its location. Since data can now be provided by the sensor network, we can take that information and send text or email alerts to maintenance personnel, notifying them of a system disruption.  Once that email alert is received, maintenance can locate the specific luminaire on a virtual lighting layout via their internet browser.  And speaking of location, luminaires can also provide application-specific services to parking patrons.  With intelligent lighting (located everywhere) we can track available parking spaces in a structure or lot, creating efficient notifications to inbound customers looking for an open spot.  But why stop there?  Once parked, why not deploy a mobile app that guides patrons from their car into the facility and back again once their visit has concluded?  In essence, our lighting system can act as a local satellite network, providing services unique to a particular application.

The lighting landscape has changed, there’s no longer a simple answer as to whether we want lighting controls.  We now have to ask ourselves a series of questions:

  1. Do regulations require I purchase lighting controls?
  2. Do I want my system to provide data?
  3. Are email and text alerts important to my operation?
  4. Are there other services I can provide with my lighting system?
  5. What support or warranty does the lighting control manufacturer provide?

The last question is critical.  As the industry grapples with the technology shift, an unprecedented number of start-ups are jumping into the fray with warranties longer than the lifespan of the company.  Remaining diligent in vendor selection and asking a few probing questions can lead to a beneficial controls solution that will positively impact our monthly cash flow—saving energy while providing a unique experience for the customer.  When we show a friend our new smartphone, we delightfully talk about its apps, camera quality, user interface, and so on. The conversation then ends with, “and by the way, it makes pretty good calls too”.  We’ll soon talk about our lighting features in a similar manner…and by the way, the quality of light is pretty good too!