Energy-Saving Forum

Energy-Saving Forum

What applications have key energy savings prospects for the electronic design engineer?

We at Electronic Products Magazine feel there is a great opportunity for the design engineering community to take a leadership roll in reducing unnecessary energy use and there-by improving the environment. Along with a series of articles we are doing on the topic, we recently gathered twelve top technical people from industry to get their ideas. Due to the length of the discussion, we excerpted the key points for the magazine (February 2007). The entire forum can be found below.

Jim Harrison,

Electronic Products: There are many opportunities to save energy in electronics design efforts�including many that don't take a lot of time and don't add a lot of cost. Let's take a few areas�and start with industrial automation. Anyone have any particular comments in that area?

Andrew Soukup (DSP Marketing Manager, Texas Instruments): I would put out one thing I'm aware of, the CEO of ABB, one of the leading industrial motor drive manufacturers in the world, has stated that 2/3 of the electricity used in the industry is used to run electric motors. And only 5% of the motor applications are equipped with variable speed drives�which enables them to use 1/8 of the energy used by their constant speed counterparts. And, the 5% of efficient motors in use save the energy produced by ten power plants and annually prevents the emission of 68 million tons of greenhouse gases.

Andrew Soukup

Electronic Products: So the savings that we're getting now from this small 5% coverage has already providing this amount of energy savings. And if we change all of them, we'd be in really good shape.

Andrew Soukup: Exactly.

Electronic Products: When we talk about a variable speed drive is that necessarily an AC three-phase motor?

Andrew Soukup: You can do you close loop variable speed control on many different types of motors. But three-phase AC induction and brushes DC motors are two widely used examples of that. The idea is closed-looped control, which allows your overall energy usage savings.

Electronic Products: So variable speed being the key – replacing on/off control.

Andrew Soukup: Right. Think about your air-conditioning�your home air-conditioner�the thermostat goes off just to change the temperature of the air by 3% and it runs full blast. Variable speed allows it to instead provide just the amount of air flow needed. You don't need to run full out.

It is intelligent control. And other aspect of it is that more intelligent speed control can help your the OEM reduce system cost. You do not have to over design the control system to be able to handle peak usage.

Electronic Products: Maybe you can use a smaller motor?

Andrew Soukup: Smaller motors, smaller power FETS.

Electronic Products: Okay and then the additional cost of the control system, I don't know how we put that into some kind of a perspective.

Donald Humbert (Vice President of Marketing, Power Management Products, IXYS): I think more and more options are becoming available for simplification of driving the motor and it is really an extension of industrial automation applications. As the solutions become more integrated, easier to implement, and more cost effective, then you'll see, this has been talked about for the last ten years, the adoption of variable speed drives (VSDs) into the various applications�commercial and industrial applications.

I think you are starting to see more and more adoptions, but I don�t think we�ve seen the explosion in the adoption of VSDs globally like we�ve had expected yet. I don�t know if anybody else can comment, but I have started to see in Asia applications, like in air-conditioning, moving to distributed systems and being very common because of cost and trying to keep the demands on power generation low. And, I have started to see that somewhat here in the States, where they�re starting to think like that.

Donald Humbert

Electronic Products: And when you talk about simplicity here, you're really talking about a higher level of integration that you guys are supplying and make it easier for the design engineer?

Donald Humbert: Correct. Everybody is looking at that in the market in terms of finding better or more economical and more rapid implementation of efficient drives.

Electronic Products: And you think we've made significant headways in that area?

Dr. Aengus Murray (Director of iMOTION Products, International Rectifier): One comment I think we can make is that in factory automation variable speed drives have been used for quite a number of years�in areas like machining and assembly equipment. And, those situations require the performance of variable speed. But, over the past few years, the same kind of control techniques are now being designed into appliances like washing machines and air-conditioners where you're now using a high efficiency motors.

Dr. Aengus Murray

Good control techniques and torque or field-oriented control is now being applied in washing machines. Ten years ago they would say, “a washing machine. You just turn on and off, why do you need such precise control?” But by applying precise control of torque and speed, you can improve the washing machine, use less water, use less energy in heating the water, and in air-conditioning, you can use a more efficient motor. Air-conditioning is about 15% of the total electrical load.

Electronic Products: Okay, of all energy in the U.S., 15% is air-conditioning?

Dr. Aengus Murray: I can say about 30% of the U.S. energy is used in domestic applications, and about 30% in commercial. Of that, each of those, air-conditioning accounts for 16% of the domestic electricity usage. I think in�on the commercial side is up to 25%�so quite a substantial amount of energy is used in cooling.

Electronic Products: I guess what you're saying is that industrial automation�factory automation right now is not a really good place for saving energy, because they've already stepped up to that pretty much.

Dr. Aengus Murray: And in terms of assembly equipment and so forth, they already will go for the most efficient motor.

Electronic Products: So probably the prime areas are where before low cost was the key thing, such as consumer appliances, and so forth, and now we can step up and put the more efficient devices in there?

Dr. Aengus Murray: And, when you put a highly efficient variable speed motor in a washing machine, and you save money on the motor because it is smaller. And you can eliminate a lot of the mechanics that were previously there with the fixed state system.

Rich Fassler (Director of Product Marketing, Power Integrations): As we talk about industrial controls and our appliances get smarter and use a more energy efficient ways of driving the motor, the other side of that, of course, is while those products are sitting around waiting to do something there is the stand by mode. I think that this number is relatively good for most developed countries�about 10% of the energy used is wasted by products just waiting around in stand by mode.

Rich Fassler

And another aspect is the efficiency of the power supply for the control system.

Cary Eskow (Director of Solid State Illumination Business Unit, Avnet): Another perspective is the overall environment and it might be helpful to step back and look at from an overall energy usage standpoint, what are the first, second and third largest consumers of energy.

Cary Eskow

That there may be opportunities there for tremendous advances, and there maybe things that we can't optimize any further. I don�t mean to move this into different direction, but something that we have certainly been looking at closely is lighting. One of the Department of Energy's most recent analysis of global energy indicated that 21% to 23% will be used for lighting.

We have so many tremendous technologies represented by the people on this call and in other industries, yet the technology for lightning has remained the same essentially since the filament was developed by Edison in 1879. So I think of this is the critical path for optimization. There are many areas�and certainly lightning isn't the only one and energy efficient motion control is important—but it seems such a shame that something this simple has been taken for granted.

Rich Fassler: There is a lot of work that being done with high brightness LEDs. The lumens/watt continues to increase for them. And you can look at what California is doing with their title 24 dictating certain minimal levels of efficiency for lighting new buildings.

The European Commission is embarking on a huge directive to increase the energy efficiency of all what they call EUPs or energy-using products. Office lighting and street lighting are right up there on the specific directives that they're working on.

So lighting is critical, and I think it's starting to get some traction.

Electronic Products: Yes. I want to back to lighting a little bit later. We've got to kind of keep this in order here.

Laurent Jenck (Director of Power System Engineering, On Semiconductor): I would like to complement what Rich Fassler said about the standby power of power supply. It is very true that a lot of power is wasted in standby power.

But I think more important is the lack of efficiency of power supplies in active mode. Regulations have gone first after the low hanging fruit, which was standby power, it's important now to go after the efficiency in active mode. And that's what newer regulations like the ones from the CEC (California Energy Commission) have been doing.

Laurent Jenck

Andrew Soukup: Related to that topic, I believe there's an energy efficiency rule looking specifically at the area of desktop PC power supplies called 80 Plus. Perhaps others have heard of it as well?

Katharine Kaplan (Product Manager Consumer Electronics, U.S. EPA): At Energy Star we just completed the development of a new computer specifications that covers desktop/notebook computers and calls for very efficient internal power supplies as part of that classification.

Katharine Kaplan

They are essentially the 80 Plus power supply and we are also requiring an efficient external power supply for a notebook computer.

Electronic Products: So 80% efficiency is the target there. That seems like pretty easy. I would have thought that most of them are 80% already.

Katharine Kaplan: Hovering in the 60s.

Electronic Product: Really?

Rich Fassler: And it's 80% at what is it, 20% and 50% and 100% load?

Katharine Kaplan: It is actually 80% minimum efficiency at 20%, 50% and 100% of rated output and we also call for a power factor of greater than or equal to 0.9 at 100% of rated output.

Rich Fassler: It's also a two watt no load standby. Is that right, Katharine?

Katharine Kaplan: Yes. Different standbys for different products, notebooks have a lower stand by. But generally a very low stand by and sleep mode.

Donald Humbert: I believe that the California standard is probably the most stringent, is it not Rich?

Rich Fassler: Well the California standard and the EPA standards are pretty much the same, the big difference is the California standard is mandatory. And that's really what got the attention of power supply designers.

Electronic Products: Whereas the 80 PLUS is something you can sign up for then you can put the sticker on your box, but it's not mandatory.

Alfred Hesener (Marketing Director, Europe, Fairchild Semiconductor): On that topic, I don't know how it is in the U.S., but in Germany when you go into a shop to buy white goods, like refrigerators or other appliances, there is a label on that appliance that indicate the energy efficiency class of that device. And that's mandatory. And consumers are more and more directing their choice towards the appliances that cost less over a lifetime.

Alfred Hesener

Rich Fassler: I don't mean to take it off of industrial, but it looks like it's going that way.

And maybe I'll have an opening here for the gentlemen from Sun. In today's business section of the San Jose Mercury news, the biggest headline was energy crisis seen for tech. And, it talks about meeting that number of Silicon Valley computer/server manufacturers had with the feds to talk about potential energy crisis in the IT sector.

And certainly, there's a lot of work to be done there. I know Energy Star is involved with Sun and other on coming up with some regulations for energy efficiency in servers.

Electronic Products: We're moving now from home PC or home office PC to the servers which involve the big servers farms that Google and all these guys have, right?

Rick Hetherington (Chief Architect and Distinguished Engineer, Sun Microsystems): Yes, we've been actively involved in pushing energy efficiency with our T2000, T1000 servers, and it's interesting that power supplies came up and we find that being one of the most inefficient areas of servers.

Rick Hetherington

And, when you multiply that by 20 to 40,000 servers in a large data center, it adds up and it's pretty significant. So likewise, my question was, are we extending 80 PLUS regulations to the server world?

Katharine Kaplan: And I have one clarification before we move to that. The EPA and Energy Star does not put out regulations, when it comes to energy efficiency, we're a voluntary program. I think someone mentioned the fact that we were setting a regulation for servers, it's really guidelines. And we are now working closely with industry as well academics like John Cooney from Lawrence Berkley Labs to develop baseline information related to servers to decide what the right next steps are.

I know that there has been talk by the 80 PLUS program about shopping an efficient power supply program to the server world. But it takes consultation with them on where that stands and certainly Energy Star has looked at a specifications for server products.

Donald Humbert: Well, central office equipment and data center servers have been the big driver for higher efficiencies just on economics because, I don't remember the statistics, but every x percent efficiency improvement in their systems translates directly to an operating cost improvement for them.

Andrew Soukup: I believe in server farms the electricity cost for heating/cooling and powering the servers is, in many cases, equal to or potentially greater than the cost of the actual servers themselves.

Rick Hetherington: The numbers I'm hearing is that it's about a three year ratio�that is the operating expense over a three year period is equivalent to the procurement cost of the servers.

Andrew Soukup: So it's obvious that more intelligent ways to manage power and climate control and the power supplies of the servers is a huge area for improvement for the power supply industry and one of the things that's driving more intelligent digitally–controlled power supplies.

Electronic Products: Okay. We'll get back into that in a little it more detail. I wanted to touch on one other area quickly.

What about elevators and escalators? I guess that's back in the industrial sectors. Is that an area that anybody's paying a lot of attention to? It certainly seems like they consume a lot of energy.

Laurent Jenck: I think you have to look at the numbers�look at the number of the power supplies worldwide. So you're looking about 6 to 10 billion power supplies. The U.S. has about 2.5 billion power supplies and about 400 to 500 million new power supplies every year are sold in the U.S.

So you have to look at these numbers compared to the elevators and the rest of the industrial applications. So we have to go after the big items.

Donald Humbert: I mean the only thing I can interject there I mean, obviously, the biggest potential for improvement there is it really just fundamental improvement and the principal switches and other devices used in those applications�in the IGBTs and rectifiers. But in terms overall impact in energy consumption, I agree it wouldn�t seem as though that was a significant player in the role on energy consumption in the marketplace.

But in terms overall impact in energy consumption, I agree it wouldn't seem as though that was a significant player in the role on energy consumption in the marketplace.

Katharine Kaplan: This is Katharine. I just wanted to weigh in and I know we touched on this a little bit. But because of sheer numbers, we at Energy Star has felt that real opportunities exist in the IT and CE arenas. We haven't really talked about consumer electronics very much. 275 million pieces of imagery equipment in use in the U.S. everyday, consuming $3.6 billion in energy. For computer equipment, 180 million computers being used in the U.S. These each use 2% or a little bit more of U.S. electricity, those are big potentials.

So we at Energy Star have just put out new specifications for both categories. We're now looking at consumer electronics, TV, set-top boxes, etcetera. So individually maybe not such huge energy users, but then when you look at the number across the country it's hard to ignore.

Jon Hancock (Applications Engineering Manager, Infineon Technologies): I really have to back her up on that, and when you look at the net total efficiency, although I think 80% is great, I wish the EPA would implement a staggered program over years just like it's been done for standby power because right now. I can tell you the people designing these 80% power supplies are shooting for 80.5% and won't spend a nickel more than it takes to reach that, because the fundamental issue is that, still, many of these factories are very sensitive to the upfront cost and are real resistant to increasing the cost of the product for savings in energy later.

Jon Hancock

Electronic Products: I want to make sure I understand the 80%. That 80% going from the ac lines to the dc output.

Jon Hancock: Yes, to the dc output. Normally, the transformers in these power supplies are switched and are operating at high frequencies, for instance in the 1 kilowatt server, the power loss of the transformer itself is only three or four watts tops. So the biggest losses tend to be things like the passive input bridge rectifier, the primary PFC switches, and the secondary output rectifiers�particularly if they�re not synchronous rectification.

Rich Fassler: I'd like to just weigh in on the point that was made on consumer electronics and set top boxes and televisions. As we're moving to larger and larger TVs. I think I've seen a statistic somewhere that stated that the new widescreen TVs are using as much energy as a refrigerator.

Electronic Products: A lot of people think that LCD TV's are taking less energy, but I don't think that's the case.

Donald Humbert: We've been selling into the Plasma market and into the LCD TVs, and the consumption of power for the Plasma has been a big issue, not so much for the efficiency, but just for cost and life of the product to things like that. And there's been a significant drive for reducing the consumption and that's obviously a huge market and is obviously becoming a bigger player in terms of energy consumption in the home.

Alfred Hesener: Talking about consumer applications, I guess it's true for most parts of the world that consumer applications are running most of the time in standby. And this standby consumption is a significant portion of the energy consumption of appliances.

Laurent Jenck: And can give you some numbers. We did a reverse engineering of set top boxes, it was the high end set top box with an integrated hard drive. The power supply was taking 80 watts and in standby it consumed 40 watts.

Rich Fassler: I would also make a statement here about standby�and that is to reach a low standby power is essentially free. A very�very important comment was made earlier about many designers and manufacturers don't want to make a design change that's going to add cost.

But, meeting low standby power goals costs nothing. There are circuits and ways to do it that are extremely cost competitive that allow people to easily meet a 1 watt standby. And there are circuits for low power chargers that can easily have a no-load draw of less than 100 mW.

Laurent Jenck: And I will second what Rich said. We did the tear–down of the power supply of the set top box, we estimated the cost of that power supply to about $10, we redesigned the power supply and with existing controllers and we're able to reduce the standby power to less than 1 watt, and we saved about $3 in the overall cost of the power supply.

So, I would like people to think that efficient power supplies are not more expensive.

Donald Humbert: I think it's really just fundamentally taking that into account on the front end of the design cycle using the various techniques of cycle skipping and so forth.

Jon Hancock: You better talk to the system architect also, because a in lot of these set top cable boxes their so-called standby or off mode is designed to be powered up with the process running the RF circuits so they can receive downloads and they have a so-called standby power which requires 14 or 15 watts. There's a lot of discussion in the cable business how to reduce this, how to change the architecture, and still provide the background services the consumers expect.

Rich Fassler: Yes, you're absolutely right. I know Katharine can probably talk about an issue coming up with some good efficiency standards.

Laurent Jenck: It's not just an efficiency standard. What set top boxes need to have is a awake–up from the network.

Rich Fassler: Right. That is starting to be addressed, there is a new Digital TV adaptor standard, and within a next couple of months the Energy Star will come out with a spec�is that the right word Katharine?

Katharine Kaplan: Yes, and it's actually going to effect at the end of January.

Rich Fassler: And what they included here was an auto shutdown mode which is addressing the situation that setup boxes have to be on all the time to receive information from the service providers.

Edwin Kluter (Marketing Manager Power Solutions, NXP Semiconductors): Because basically, the power supply technology is there. It's really easy to just wake up on any microprocessor signal coming in and just power up the whole supply to deliver maximum output.

Edwin Kluter

Electronic Products: Are there any new topologies in AC to DC conversion that are really going to make a difference or we pretty much have that down right now?

Edwin Kluter: I think we pretty much have that now. Many of the supplies have the technologies to run all kinds of smart modes so we go to cycles skipping modes or lower frequencies to get to a low power state.

Alfred Hesener: Most of the topologies that are being used in switch mode power supplies are actually known for 20, 30, 40 years or more, but some of these topologies are now becoming more interesting because new power switch technologies are available. For example, rectifiers in materials like silicon carbide and similar types that allow the cost efficient use of those topologies now.

Andrew Soukup: The other aspect�as we talked about at the beginning of the forum�is moving to a variable speed drive versus simple on/off for motors and going to vector control. So more effective efficient control of motors.

We can envision a similar switch at some point with power supplies to move to nonlinear types of control to improve the efficiency as new technologies become available and very cost effective. You can see a large growth in efficiency when you have that equivalent of the variables speed we talked about for power supplies.

Laurent Jenck: I just would like to answer quickly your question about the technologies. Just like Alfred mentioned, the topologies used in switch mode power supplies have been known for many years so like flyback or forward. So, what I would like the readers to realize is that topologies that enable them to meet the regulatory standards don't require new revolutionary architectures, but more refinement of existing topologies like, for example, forward using active clamp or flyback active clamp or techniques like quasi resonance or full resonance in full bridge or high bridge topology.

So we're talking about refinement of existing architectures and topologies, not something that requires a brand new revolutionary architecture.

Donald Humbert: I just want to emphasize a point that was brought up earlier but applies just as well here. If the standards aren't in place, the market is very much driven by economics, value engineering. We've seen the price of your Dell computer, or whatever, dropping through the floor, and the market has become very good at squeezing every cent of cost out of the system�power supplies included. So, the advantage of having some of these regulations in place is it will drive this activity.

Dr. Aengus Murray: Another aspect that this is, a lot of technologies are available, but one thing that holds back the implementation is the availability of design tools and architectures that are easy to implement. So one important aspect is how we enable worldwide to access the technologies. So it's not necessarily the availability of the architectures, which is how easy it is to adopt these.

Electronic Products: So let's move on quickly to what I call wall warts or the external power adapters. I probably have about 12 of them here I my office. The printers all have them, many office devices have them. And I know California recently changed their regulation, so that the standby power on those is not so high. The cell phone charger is another one. My cell phone charge is plugged in all the time, and the cell phone gets plugged in three times a week or something, so�

Katharine Kaplan: You should unplug that.

Rich Fassler: Certainly a big part of our revenue that comes from the wall warts. Let me just say that the standards are there. Certainly a big nod goes to EPA, Katharine's group there, and the California Energy Commission for coming up with the specs that includes active mode as well as no load. And that spec now, without a doubt, is becoming the standard around the world.

Electronic Products: And circuit-wise, is that easy to implement?

Rich Fassler: It is absolutely easy to implement. It's available from a number of different suppliers including Power Integrations. It is cost effective. And there's really no good reason not to adopt it.

Electronic Products: Right now, Katharine, if we go by a new external power adapter can I look at the outside of it for an Energy Start label?

Katharine Kaplan: We actually do have an Energy Star labeling program for external power supplies for battery chargers. They do have a label. It's a different label for the power supply, but it's called Energy Star.

Rich Fassler: That spec that the EPA and CEC came up with for external power supply, I think it's up to 250 watts, has been adopted by a number of the states in the U.S. It's been adopted by the European Commission on the Code of Conduct starting in January 2007 and adopted by China, it's been adopted by Korea, by Australia, so it's really made a big impact.

Electronic Products: Now, what about power factor correction? If I put power factor correction in an ac to dc supply, that's going to use some energy, right?

Jon Hancock: No, not really. Not in the net results. First off, if you don't have power factor correction in it, you always an issue with the power factor with the real power consumed is much different from the apparent power and the load on the grid is another aspect to the problem not just the thermal losses inside the power supply itself.

Secondly, if you use power factor correction then you have a regulated bus voltage for the dc to dc converters and they can be sized and optimized to operate most efficiently in that mode at the minimum cost, whereas if they have to handle a wide input voltage range, then the design overall has to be more complex.

Electronic Products: So if I have 100-watt DC to DC power supply right now, I have power factor correction to it, how much energy did that save?

Jon Hancock: Well, the controller itself probably takes 50 to 100 mW for the control chip itself. The rest of it is really is a function of what components you use. And this is where the points that Alfred had brought up early comes into play.

The advances over the last six years in high voltage power semiconductors has made it possible, for instance, to do server power supplies that from AC in to DC output hits 90% plus efficiency. That's a much higher target than the EPA target of 80.5%. Eighty point five percent is a very limited target, due to the issues around silver box economics. Manufacturers just don't want to put more money than that into the power supply.

Electronic Products: But going back to power factor correction. Does it save energy?

Donald Humbert: When you have to design for a very wide input range, which you normally do—especially if it's going to be universal supply or something that�that definitely is the driving factor on terms of how you're going to compromise in terms of selection of switches or whatever and the magnetic, etcetera. But if you go with a PFC front end, you can make all the down stream dc/dc converters easier and more efficient.

Alfred Hesener: I'm a little bit surprise about this discussion since in Europe, the use of PFC stage in certain applications is actually mandatory. So, for example, in lighting application, above 25 watts power, you must have a PFC stage in your application.

And so, people don't really question or argue with that anymore, they put it there, and they put it not only because it's mandatory but because it improves the energy efficiency since�for example, the lamp ballast manufacturers that are here in Europe, they design to customers not only for Europe but for a worldwide usage, so most of that stuff actually has a wide input voltage range and so the PFC significantly helps to improve the efficiency in lighting applications.

It's particularly interesting for people that are building large office buildings, the big new buildings in Shanghai, for example, when you use�I don't know�10,000, 15,000 lamp ballasts in one building. Those guys need to size the copper cables in the building by the energy that has to flow through that cable.

And if the power factor is not good then the current flow is much larger, requiring bigger cables. And with the cost of copper increasing over the last years that has a significant impact.

Laurent Jenck: This is correct because the all the infrastructure to carry, transport and deliver the electricity has been sized, and the�so it's been sized to deliver the apparent power. If you have a power factor correction close to one, then you can reduce the size of all infrastructure�the cable, the poles, all of the transformers.

Jon Hancock: It's a question of what actual usable power can you get out of the lines. So if you have, say, a 2-kilowatt service and you have a non-power factor corrected group of power supplies running on it, like older PCs or even most modern ones in the U.S., unfortunately, then, the actual power that you can pull off of that line with a typical power factor at 0.6, with a capacitor input configuration on a power supply with a bridge rectifier, that means that, basically, you're wasting 40% of the incoming power before even you send it to switches and power conversion.

Electronic Products: So power factor correction could be a big element.

Jon Hancock: Yeah. In Europe, the consumer equipment now 75 watts input power and above does require power factory correction. And it should be here in my opinion.

Rodger Richey (Senior Applications Manager, Microchip Technology): A question for the EPA: Why don't we have power factor correction regulation?

Rodger Richey

Katharine Kaplan: Right. I actually would say that's probably not an EPA thing. I did mention that we included a power factor correction requirement in our computer specification, but I would probably have to nod to the DOE on that one.

Dr. Aengus Murray: It is probably of the interest of the power utilities here, and we don't have any power utilities on the line, Jim. But I think that would be a question for them here.

Andrew Soukup: To comeback to home appliances, white goods are a very ripe opportunity for power factor correction.

Electronic Products: Digital feedback loop supplies�the newer versions of the full digital feedback loop. Do they offer an efficiency advantage?

Dr. Aengus Murray: I think if you can integrate the power factor control in with the system control, you can have better overall management of the system. You can adjust your dc bus voltage to match the load conditions. So combining the two is often better than just having a separate input power factor stage independent from the controller.

Andrew Soukup: The other portion of that is, as we talked before, the digital control loop allows you to more intelligently manage your supply. You get the variable feed equivalent that we talked about before.

Electronic Products: Rodger from Microchip, do you have any comments on that?

Rodger Richey: There's certainly a lot of gains to be made in having more efficient power supplies but�take an example of Dell's computer switching from Intel processors to AMD processors to lower the power. There are a lot of gains in power supply efficiency, but there are gains as well that we can make in the semiconductor devices themselves.

Jon Hancock: One of the trends that is fortunately happening is that�not because of power efficiency per se�but the fact that people like quiet computers, and quiet computers mean no loud fans running, and that means less power dissipation. So that there is a significant migration�or at least some migration of the active implementation of the types of power management functions that we've had for years in notebook computers into the desktop format.

And when you look at that, you see a number of different desktop computers now coming online which use chipsets and the software previously developed primarily for notebooks including even Intel�s processors, which come from their last generation notebook line. Then, you have a situation where the desktop PC, under most conditions, maybe loping along in a relatively low power level and only when you see something like doing a Gaussian function in Photo Shop, where really it has to start doing some crunching, only then do the fans start turning.

In your standard PC there's no active management of the hard drive power. There's no active management on fans or anything else. That's changing.

Alfred Hesener: It's especially the need for power supply modes, which would raise the overall system efficiency and the more modes you need, the more control you need, and in that case, digital control is useful. Full digital control power efficiency, let�s say, vs. a modern resonating supply is not more efficient. What it can do is instantly switch modes and has the ability of going from stand by to full on or to a bridge mode and that is where you will get the overall system efficiency.

So the first part where you will see digital power is in server farms, and in infrastructure server racks where you have a lot of power to manage and usually only 10 or 20% of full power needed there.

Donald Humbert: I do think you are seeing adoption of digital control where it makes sense. You're seeing lighting systems move towards digital solutions, and then you can integrate power conversion functions with the rest of the control algorithm or if you have a digital PFC with a lighting product.

Andrew Soukup: And that's what really will help you drive your overall cost further through that kind of integration.

Rick Hetherington: A couple of comments about processor power. There are a lot of engineering efforts that are going in to reducing power of the processor, but at a server level the power focus is moving into memory, fans, power supplies, and spinning media like disk drives. So that tends to be where the power saving effort is concentrating.

There is a trend to look really at the global data center from a power perspective and managing power that are much more efficiently, and it's coupled with a technology called virtualization. VMware is out there with that. We'll have a product fairly shortly and be using products like this where servers are lightly loaded.

Today, the tendency is to keep server utilization levels at around 15%, and don�t exceed that. Typically, server power is there for handling some of the peaky periods. And with more intelligent management of data centers, we could migrate jobs from lightly loaded servers and then power those servers down and have better utilization of the other servers. So that's a trend that�s we�re just very in the beginning stages, but there's some hope there to save power in the data center level.

Electronic Products: Rick, what about, and maybe anybody else on this, what about the communication links, the Ethernet and fiber optic connections, is there possibly significant energy saving we could do there?

Rick Hetherington: I don't really know. I have a feeling that there is not a great deal of power at the moment in the Ethernet and other data connections.

Electronic Products: I know that each DSL connection used to take about five watts or so, and now it's down to a watt or so. But, there's a heck of a lot of DSL connections, so I would think that would add up, anybody else want to comment on that?

Edwin Kluter: It's more in the network routing. It's not so much power for the cables and the energy needed to supply the signal. So it's sheer computing power, which is in the routers.

Electronic Products: Okay. So, now let's take it back and think about in the general perspective, what new technologies that are either coming onboard right now or do you see in the future might engineers use to save energy?

Laurent Jenck: I just wanted to answer that question and also add to the servers topic. We talked about 80 plus being applied to servers. I don't think that 80% efficiency will be enough and the industry should go for 90% efficiency. To do that would call for a complete overhaul of the architecture instead of having a box with an ATX type power supply with multiple outputs.

So you're going to have the single 12-volt output at 90% efficiency with power factor correction, and then that 12 volts is going to be routed on the motherboard to voltage regulator modules.

Electronic Products: But then, you have to add the efficiency of those down converters.

Laurent Jenck: Yeah, but I personally believe that this is going to be a more efficient architecture than having 90% power supply with six or seven different output voltages.

Jon Hancock: I mean, this is basically the type of configuration that's used in a lot of the higher power servers today anyway, where the main server power output supply is at 12 volts.

Rick Hetherington: That tends to be what we do is 12 volts out of the supply and then step down as it's needed.

Electronic Products: You do that conversion on card. What is the efficiency, typically, of the DC to DC converters? It's nice to talk about that 90% you have now upfront but you still have of that other converter and they're probably 90% as well, so you end up back at 80.

Alfred Hesener: I think the gain in a chain like this so going into the 12 volt bus and then the advantage in regulating decentrally would be that you move control of supplies.

Electronic Products: Yes, it meets the needs of the standby situation again that we keep getting back to.

Jon Hancock: One other point, even for the current PCs, most of them have to have additional internal converters because the original PC ATX output voltages don't meet the requirements for lot of the subsystems. So you've already got those POLs all over the place.

Laurent Jenck: So your question was, what new technologies are coming or going to be required to meet energy regulations. Again, I really want to emphasize the point that in switch mode power supplies the topologies has been known for years. So we're not talking about revolutionary architectures, but more refinement to existing topologies using techniques like soft switching or quasi-resonant and using MOS FETs for synchronous rectification on the secondary.

So both these technologies, again, are available right now in production. So it doesn't require anything new or any rocket science to meet the regulations today.

Alfred Hesener: I agree, however, talking about new technologies that designers might use for improving the energy efficiency in the future there is some stuff happening at the discreet device level. For example, the high voltage power MOS FETs that are being used have become much better over the years.

Electronic Products: Lower on resistance?

Alfred Hesener: Yes, but also the gate charge is going down. The devices are switching much faster. And so the challenge for the design engineers who use those high performance devices is to drive them correctly so as to avoid other problems in the application like ringing, high peak voltages, high di/dt, EMI issues, that kind of stuff. So it's not without the challenges to use the more modern power devices.

Jon Hancock: With the newer devices that are out you could switch at a very much higher frequency and get the efficiency of a lot of the older standard devices, or you can keep to a lower frequency range, if you want a bigger power supply, and typically cut your power losses in half. This is because the intrinsic output capacitance.

This capacitance, due to improvements in the device or reduction in chip area, has been cut by over a factor of two, close to a factor of three now. And that greatly lowers the switching losses.

Donald Humbert: Be aware of the advances and improvements and benefits to be had from even your more traditional switches. We're seeing additional improvements in bipolar technology. We have improvements going on in ultra fast rectifiers and more high end, high performance rectifiers like gallium arsenide and silicon carbide.

And all these provide additional potential benefits in the system to be had from switching losses and in soft recovery. These are extremely important in terms of trying to raise that switching frequency.

Rich Fassler: Besides the devices getting more efficiency, the power supply designer still has to be very clever in their overall design because the design has to have a fairly constant efficiency over a wide load requirement.

Electronic Products: I want to move now back to the lighting sector, which we didn't cover real well. Cary from Avnet, there are different factors here, I mean, I don't think anybody envisions all the incandescent lamps being replaced by LEDs right away, or do you?

Cary Eskow: No, not at all. As a matter of fact, the current infrastructure is almost the opposite of what you need to effectively use LEDs. In a traditional incandescent bulb, most of the energy�about 85%�gets radiated out as heat. And the traditional light bulb socket, the Edison socket, is a thermal insulator. In an LED based illumination system no energy is radiated as heat. You need to conduct heat out. So the reengineering needs to begin with the overall solutions.

Spectral feeding existing light bulbs with LED based solutions might be a temporary or noble approach, but to really harness the benefit of this type of technology, engineers, architects, specialty lighting people will have to look at what are they trying to accomplish, what are the energy efficiency goals and begin looking at it from that standpoint.

A traditional incandescent bulb is about 13 lumens per watt, which is very inefficient. And even the more efficient replacements, the compact fluorescent are about 80 lumens per watt. I have in front me a device that's 100 lumens per watt and that's a LED.

Electronic Products: I think the very best fluorescents are up near 100 lumens per watt, aren't they?

Cary Eskow: Yes, but then LEDs have achieved the crossover.

Rich Fassler: Right. But you can't get the same amount of aerial lighting out of that 100 lumens per watt LED that you can get out of the 100 lumens per watt incandescent.

Cary Eskow: Well, perhaps�perhaps not. Our traditional, especially fluorescents and even the regular bulb, light source comes out in all directions. And to harness that in a way we can make a down light or light up a surface, the optics reflectors�there's about 15% loss even from that perspective. All LEDs emit light from a surface.

So when you look at the overall system, you're absolutely right. You have to look at how the light comes out, how you the light is gathered focused. We have achieved the crossover of efficiency with fluorescents. But what we have not achieved is the knowledge of how to really build the products effectively with LEDs. They look so simple, but the engineering is difficult.

Donald Humbert: I don't think there's going to be, at least for the foreseeable future, a panacea where there's that one solution fits all. I think that you're seeing improvement in the high intensity discharge lamp in terms of their product life and their efficiency and across the board in the fluorescent technology where the dimmable versions are now coming around.

Active control has been a challenge because you don't want to rewire an entire building, but as Zigbee comes on line as another other means of interfacing into intelligent ballasts the standby power modes for these things and the ability to reduce power consumption and the lighting in buildings becomes more possible and more doable. I think the jury is still out. I think you're seeing all of these technologies competing and trying to improve and be better.

Edwin Kluter: I think from an energy standpoint, it's not the discussion of whether the new technologies will inhabit the lighting space�they will. Technologies are there too miniaturize them to make them just a small as a 16 watt glowing lamp, and this should be promoted in all regions around the world, as that saves an awful lot of energy.

Katharine Kaplan: It is very good conversation about the here and now as well as longer terms. I would lay in on the fact the CFLs are here now and they work, they use much less energy than a standard incandescent, and last up to 10 times longer. And I think there's the potential for a really significant uptake because they work in so well in the existing infrastructure. If every home replaced one light bulb with a high quality CFL, we could save enough energy to light more than 2.5 million homes for a year�that's a big deal.

Cary Eskow: But don't you agree Katharine that there has been a relatively small adoption rate of CFLs. I don't have one in my home. And I'd like to but the embodiment is it is just not that attractive, very much so in a commercial environment, but for residential use, it's not quite saleable?

Electronic Products: You mean because they're not pretty?

Cary Eskow: The color of light, the quality.

Katharine Kaplan: I think things have really changed.

Edwin Kluter: We are working with a couple of customers and they are bringing out lamps which are exactly like the pear shaped bulbs. And so by putting an extra layer of glass around the actual CFL tube, they resemble a normal lamp.

And in this layer of glass, they can also have warm colors. You can also do that with CFL�so that's not the issue.

Cary Eskow: I just wonder why the adoption rate is low for residential use.

Katharine Kaplan: I frankly think that it's just a lack of understanding. I will say that I think when these lights first came, there were some quality issues that I think we've moved partially beyond that as long as you buy from a reputable company and an Energy Start labeled bulb, the consumer can be very comfortable.

Electronic Products: Well going back to Carrie, one big application for LEDs is in signage. Is there potential there for a lot of energy savings?

Cary Eskow: Well it depends, the largest market for signage is actually is something called channel lettering and the appeal for most customers isn't really the physics for physics, it's economics. If you look at the sides of buildings that have letters that are lit up from behind�that's what a channel letter is. There are strips of lights in back of that and that the maintenance cost of going up there on a cherry-picker and replacing a letter at a time is prohibitive.

Electronic Products: Okay, so it's not energy savings it's really maintenance issues here.

Cary Eskow: So we can save energy, but people are motivated less by altruism and more by economics.

Rich Fassler: It's still though an issue for energy efficiency, in other words, you can certainly light those lights with a linear transformer power supply if you wanted to, but it would make more sense, of course, from an energy standpoint, to do it with a switcher.

Cary Eskow: Yes. And you know what? The biggest, effect of that is in transportation lighting. If you look at a stoplight, they used a long-life incandescent bulb which radiates all kinds of colors and put it a filter in front of it, that lets out a red or a yellow or a green. So little light transmits through that filter, and the cost of re-lamping is very high. The energy used is very wasteful. Most cities have gone to all solid state stoplights.

Dr. Aengus Murray: Trying to put things in perspective, if you look at the domestic energy use and you look the top users—that is actually air conditioning and refrigeration at 16%.

So there's 30% use in those areas. Lighting is 9%, and a very substantial usage. And there is 42% across all the other appliances. And the power supplies in all those appliances are very important. But, major users are in refrigeration and air conditioning.

Rich Fassler: One could say well, let's not worry about little cell phone adaptor because how much does that really waste if they keep it on all the time? But you multiply it by the number of cell phones out there and the number of households, and it turns into a lot of energy. So I don't think you can't just pick on air conditioners because they're big, they use a lot of power. You really have to look at the each group.

Dr. Aengus Murray: The appliances use a lot of energy. And there's like 25 different home appliances all using a few percent a piece that add up to this 42%.

Electronic Products: Most of those are motor-drive sort of applications which we've talked about quite a bit here.

Rich Fassler: Well, the interesting factoid too, a study was recently done on new houses in California that found that before anybody even moved into the house it was using 80 watts. This was all this miscellaneous stuff the garage door opener, etc. So, it's not just the stuff we think about. We see our big TV there, we see our set-top box. But it's a whole bunch of other miscellaneous things that needs some kind of regulation or standard or spec.

Alfred Hesener: An interesting thing about the EUP guideline that has been mentioned earlier. They look not only at energy consumption during the operation of an application but also, the energy they would take to manufacture and to recycle it. So it looks at the whole life-cycle.

Electronic Products: So, let's say talk a little bit about, and maybe Katharine can start us out here, what sort of regulations are going to be coming online in the next two years that engineers need to be aware of or, around energy savings?

Can you comment on that? Is there anything new that, that you see coming in the near future?

Katharine Kaplan: Well, I can speak specifically to what we have going, and as I've mentioned before, Energy Star is a voluntary program versus a regulation.

And, we are doing as much as we can to achieve harmonization where it makes sense to do and what that means to us is, at the very minimum, to ensure that all of the governments around the world who we can engage, agree to a standard, and just testing products, so that at least, we're all measuring the energy use of products in the same way.

Ideally, we get to a place where, we're all asking for the same thing when it comes to efficiency, such that manufacturers don't have to design a different product for all different markets around the globe. We have a number of energy-efficient specifications coming online in the next couple of years, a couple I've mentioned previously. This April 1st we have a new specification for all imaging equipment�printers, fax machines, copiers, scanners. And then, in July of 2007 our new specification for computers will go into effect. And we've launched the TV revision as well as a digital TV converter box.

And then, for TVs, we expect to really work on that in earnest beginning in mid-January after the IEC completes the development of the TV testing. And I hope that we can wrap that process by late September of next year, so it can go into effect in July of '08 and also, in first quarter of '07, we expect to launch an Energy Star spec development process for the more complex set top boxes of today.

So, also mentioned that both for imaging and computers, we planned a Tier 2 specification. April '09, we'll have a raising of the bar for the imaging spec and then, for computers, hoping that in January of '09, we implement a Tier 2 which will put into play a benchmarking scenario.

Rich Fassler: The one thing that is getting some traction is a thing called a 1 watt horizontal standby standard. And basically it says that, regardless of what the product is, if it's an energy-using product, it must meet the one-watt standby.

Korea has put this as a goal for 2010, so that's three years from now. Australia just announced a couple of weeks ago that they're going to put that into effect in 2012 and our guess is that because it's simple to understand and the technology is pretty much there to do it that if you will get traction around the world.

Electronic Products: Okay. So the, one last thing. Are there any other areas for energy savings, anybody like to comment on that we didn't talk about?

Rodger Richey: We all can see there's a big push for the intelligent power supply going to a digital control using DSP to get the system efficiency up, and that's been a huge area for us.

Alfred Hesener: Let's not forget that one of the biggest sources of energy savings is if people would be turning off the light in the room where they are not going and this can be a big savings.

Donald Humbert: But, if you put in, if you put in to a building sensors with the ability to dim lighting that would help. If that can be adopted, then you don't necessarily have to count on the person, if you have various sensors and some control system that goes in and is looking for activity.

The only barrier there is, is the ability to install it and do it without having to gut the building. And I think that the tools for doing that are emerging.

Rodger Richey: I think further to the point of the, that sensors in the room and the cost of the infrastructure to install it, that's where new wireless technologies like Zigbee and.802.15.4.where you can actually start that working and connect lighting sources and switches. That's really going to benefit from these new wireless emerging technologies.

Cary Eskow: This will make it much more appealing for consumers. You're going to enable functionality that they didn't even know was possible with earlier technologies. Zigbee is going to play a major role in this, I believe.

Donald Humbert: I agree with that. We did some work on lighting systems and there was a lot of interest in exploiting the capabilities of Zigbee with the standards available to facilitate things like that.

Laurent Jenck: It is going to also make possible, there's some part of the world like China or Africa, even South America that currently don't have access to much lighting. So LED is also going to make it possible and bring light to entire rural villages with much less energy usage.

Dr. Aengus Murray: Jim, one comment in general is I don't think it's a lack of available technology. It's more, how we get this technology into the product.

And on the commercial side you can do the analysis. For example, a study on fans, evaporator fans, and commercial refrigeration�I can save $156 a year by switching from AC induction motor fans to an ECM fan. But the typical consumer just looks at the price of the products. So it have to be driven by a regulation for most of the consumer products.

Electronic Products: You know, I disagree a little bit there. I think if we had the energy star information on every product, on every TV, etc, the consumer would take that into account, even without a pay-off in a certain number of years, just because they're environmentally conscious.

Donald Humbert: I just wanted to point one thing out. I think we've all got to remember that the economics of energy consumption will come further into play in the marketplace, because as these emerging economies in India and China continue to advance and their populations become more affluent and they get more buying power, if they're buying more goods and doing more things, it's obvious that the energy consumption's going to go up and the cost of energy in general is going to continue to escalate because it is a finite resource. And, that will be, at some point, a dominant force.

Katharine Kaplan: Yeah, I would back that up entirely and there is an expectation that by 2030, world energy demand is going to rise by 50%.

And, we're already seeing some surveys that people are really taking notice�88% of U.S. adults responded to one study that energy efficient was very important in their electronics, appliance, lighting and heating equipment purchases. I don't think this is a bottom of the list factor for consumers anymore.