Medical Power Supplies: New Efficiency Standards are Ahead

This week the U.S. Department of Energy (DOE) has published a notice of proposed rule on its "Energy Conservation Program for Consumer Products: Determination Concerning the Potential for Energy Conservation Standards for Non-Class A External Power Supplies." In this document, DOE proposes to determine that energy conservation standards for so-called non-Class A external power supplies (EPS). Class A in DOE terminology refers to single output EPS with nameplate power under 250 watts.

For reference, currently there are three domestic programs that mandate certain minimum efficiency levels of external power supplies: the Federal mandatory standard for Class A EPSs, the EPA’s voluntary ENERGY STAR standard, and California’s mandatory standard for so-called ‘‘State Regulated EPSs.’’ They all apply to low-power single-output units and particularly exclude medical supplies. The DOE is now is trying to regulate efficiency of four more types of external power supplies that do not fall under class A: (1) Multiple output EPS (2) EPS above 250 W, (3) EPS for medical use, and (4) EPS for battery charging. The new proposed rule can affect power supplies for a wide variety of applications such as amateur radio equipment, Xbox 360, nebulizers for home use, cordless power tools, etc. Note that this rule does not set any specific standards yet; it only positively determines that future standards may be warranted and should be explored in an energy conservation standards rulemaking. DOE will be accepting comments by December 18, 2009, after which it will make an actual determination.

Green Electricity From Cars

This week an Israeli firm Innowattech performed a successful trial of their alternative energy system that generates "green" electricity from vibration caused by passing cars. The system was installed on a 10 meter strip of asphalt on a highway and powered the street lights set up next to this strip. It used special piezoelectric generators embedded in the asphalt 2 inches below its top level. The generators were mounted with electronic cards that fed voltage into a storage system.

Piezoelectric effect in general is the generation of a voltage by certain solid dielectric materials when a mechanical stress is applied to it. It has been known for more then a century, and is widely used in piezoelectric transformers for high-voltage power supplies, various transducers, sensors, cigarette lighters, and other low-power applications. The Innowattech's system called IPEG™ is probably the first practical high-power application of piezoelectricity. According to the company, the installation of their system stretching one kilometer would produce 200 kW per hour on single traffic lane, or 1 megawatt on a four lane highway. Installation of the piezo-generators and electronic cards can be performed during paving of new roads or during the maintenance work. The "traffic energy" can be either supplied back to the drivers by powering the road lights or fed into the electric grid. A variation of IPEG™ can also produce power from pedestrian movement. Harvesting energy from the vibrations created by people walking on the floor is also being researched by East Japan Railway Company, who installed “Power-Generating Floor” in a Tokyo station.

Innowattech estimates the cost of energy harvesting from roads, railways and runways via IPEG™ to be 3 to 10 cents per kilowatt, which is comparable to the cost of renewable energies.

Cheap Small Generators

If you consider buying a cheap small electric generator for emergency purposes, now it's the right time to do it. A year from now you probably won't find a cheap generator for sale because of the new EPA exhaust emissions standards that will take effect in 2011. These new standards apply to all so-called Small Nonroad Spark-Ignition (SI) Engines and Equipment with engines 19 kW used in household and commercial applications, including lawn and garden equipment, utility vehicles, generators, and a variety of other construction, farm, and industrial equipment. The standards are intended to reduce hydrocarbon emissions from small SI engines by about 35%, and are consistent with the requirements adopted previously by the California Air Resources Board (CARB). Of course, as every government regulation, this one comes with a price tag. To comply, the manufacturers have to improve engine combustion and add catalysts. They will have to apply on an annual basis for the certification and pay a certification fee. The extra cost of course will be passed to us, the consumers.

Major domestic manufacturers of portable generators such as Generac and Briggs & Stratton, are already CARB-compliant, so likely they will be EPA-certified as well. However their models cost typically twice as much as some cheap imports. Right now you can still buy a small non-CARB compliant portable generator made in China for about $100 per kW power. And if you worry about environment- emergency generators should not be an issue of our concern: maybe you would use them a few hours a year, or maybe you would never use them at all. Of course, portable generators are also used for non-emergency purposes such as on construction sites. However, as CARB's Fact Sheet admitted, small engines (which besides generators include lawn mowers and a variety of other construction and garden equipment that is used more frequently) comprise only about one percent of California’s air pollution inventory! If EPA wanted to fight this 1% pollution, it could at least allow the non-compliant generators to be sold with a label "for emergency use only". Could it be that EPA employees driving to and from their work for years while working on this project, caused a greater environmental impact that all portable emergency generators?

Environmental Design of Electrical Equipment Act and Mercury in Your Mouth

Although most of US electronic industry has converted to a ROHS-compliant manufacturing, up until now there was no a legal requirement in US to meet ROHS regulations except for the state of California. The electronic manufacturers switched to ROHS-compliant products primarily in order to sell them to Europe, Japan, and some other countries, and because many customers were requesting ROHS compliance. However, when a product is not shipped to the geographical areas where ROHS or similar regulations are enforced by a law, and the compliance is not requested by a customer, it is basically up to the manufacturer to choose the components and the soldering technology.

Now there is a possibility a ROHS compliance would soon become a federal law. A legislation have been recently introduced in the U.S. House of Representatives that imposes restrictions on the use of lead, mercury and other materials in many types of electrical products and equipment.
The proposed legislation, designated H.R. 2420 and referred to as Environmental Design of Electrical Equipment Act (EDEE), would amend the federal Toxic Substances Control Act (TSCA) to provide national regulatory standards for the use of some potentially hazardous substances. According to the bill, ‘electroindustry products’ manufactured after July 1, 2010 must not contain lead, mercury, hexavalent chromium, polybrominated biphenyls (PBBs), polybrominated diphenyl ethers (PBDEs) and cadmium in the concentration levels that are consistent with EU's RoHS Directive.

The bill particularly states: "It is the purpose of this Act to enhance the economic, environmental, and social well-being of the people of the United States in the global marketplace".

Well, I wonder how for example mandating a lead-free solder technology that is known to have potential long-term reliability issues, whose implementation requires extra spending, and which is not driven by free market forces, would enhance our economic well-being?

I also wonder, how come for example mercury is not OK in electronics, but OK in your mouth? It is interesting that currently in the US and in most European countries there is no restriction on the use of dental mercury amalgam fillings. So far only Sweden, Denmark and Norway ban mercury use in dental fillings, while all members of EU restrict its use in electronics devices. Of course, mercury, lead and other toxic substances in electronic devices present a health threat only if you have a habit of chewing printed circuit boards. Contrary to this, mercury in your mouth presents a much more probable health issue. According to some studies, amalgam fillings leach mercury into the mouth and mercury vapor can be inhaled during the fillings removal, although FDA disputes the effects of this exposure.

The state of California is a bit more consistent with the toxic substances issue. It at least mandates the following notice: "Notice to Patients, Proposition 65: Warning on dental amalgams, used in many dental fillings, causes exposure to mercury, a chemical known to the state of California to cause birth defects or other reproductive harm. Root canal treatments and restorations including fillings, crowns and bridges, use chemicals known to the state of California to cause cancer. The U.S. Food and Drug Administration has studied the situation and approved for use all dental restorative materials. Consult your dentist to determine which materials are appropriate for your treatment. "

However, currently neither CA, or federal laws restrict mercury use in dental fillings. Apparently, for our lawmakers mercury is hazardous only in landfills but not in your mouth.

Power Supply Efficiency Compliance Calculator

I previously wrote about various US and international regulations related to an external power supply efficiency. Power Integrations came up with a nice free online tool that let you quickly check whether your charger or an adapter complies with the energy-efficiency regulations. You just enter your power supply's nameplate wattage, no-load power consumption and the efficiency in the active mode at various load levels. The calculator then tells you whether you meet various worldwide standards and actually displays the required no-load input wattage and required efficiency you need for the compliance.
The calculator currently checks for compliance to the following standards for PSU<250w:

• ENERGY STAR (version 2.0), a voluntary standard sponsored by the U.S. Department of Energy and the EPA;
• EISA 2007 section 301, a mandatory U.S. efficiency standard, based on the California Energy Commission’s Appliance Efficiency Regulations;
• European Commission Code of Conduct (version 4) issued in April 2009;
• European Eco-design Directive: The Commission’s Eco-design Directive for external power supplies, which aligns with the EISA 2007 standard for Tier 1 and ENERGY STAR (version 2) for Tier 2;
• China USB Charger Specification (YD/T 1591-2006) for mobile telecommunication terminal equipment power supplies;
• EC Integrated Product Policy (IPP) for mobile phone adapters/chargers.

Hopefully, PI will be promptly updating their calculator when the applicable standards change.

Compact Fluorescent Bulbs (CFL): Pros and Cons

Speaking on April's 22 Earth Day about his energy plan, President Obama reportedly called on every American to replace one incandescent light bulb with one compact fluorescent (CFL).

For reference, like all other devices CFL has pros and cons. Compact fluorescent bulbs use up to 75 percent less energy then traditional incandescent lamps. However, they do present health and environmental hazards. I wonder if the president's advisers fully informed him of all the impacts of using these bulbs?

Last year a research by UK's Health Protection Agency has shown that CFL bulbs can emit unhealthy levels of ultraviolet radiation when they are in close proximity to people. They said that the UV levels can be equivalent to that experienced outside on a sunny day in the summer and so some precaution is warranted. The Agency's chief has suggested: "We are advising people to avoid using the open light bulbs for prolonged close work until the problem is sorted out and to use encapsulated bulbs instead." Hmm... Maybe we should use sunscreen and sunglasses with UV protection at home to protect ourself from these "green" energy-efficient politically correct bulbs?

Of course, many of us are not concerned of prolong sunlight exposure and would spend long time under the sun. Nevertheless, this WHO's warning should be taken seriously: "Prolonged human exposure to solar UV radiation may result in acute and chronic health effects on the skin, eye and immune system... Over the longer term, UV radiation induces degenerative changes in cells of the skin, fibrous tissue and blood vessels leading to premature skin aging, photodermatoses and actinic keratoses. Another long-term effect is an inflammatory reaction of the eye. In the most serious cases, skin cancer and cataracts can occur."

And although the above HPA's report says that when the CFL is further then 1 foot, the UV level is less than being outside on a sunny day in winter, it is not good enough for me. I personally don't want to subject my family to UV radiation [even a low one] for the sake of saving a few bucks or helping the utility company, or because of anyone's political agenda.

Besides being a source of UV radiation, all CFLs contain mercury, a toxin that can cause kidney and brain damage (how come the state of California is not requiring the appropriate warning label?) Based on a research by Stanford University, the amount of mercury in one CFL bulb can contaminate more than 1,000 gallons of water beyond safe drinking levels. Now, raise your hands: who will bother bringing a burnt bulb to a special recycling place [if you can find one in your area] rather then throwing it in the trash?

And what if you broke the CFL? The EPA has a whole page of the clean-up instructions, which include the following sections:
Before Clean-up: Air Out the Room;
Clean-Up Steps for Hard Surfaces;
Clean-up Steps for Carpeting or Rug;
Clean-up Steps for Clothing, Bedding and Other Soft Materials;
Disposal of Clean-up Materials;
Future Cleaning of Carpeting or Rug: Air Out the Room During and After Vacuuming.

Hey, how about just staying with good old incandescent bulbs until a safe alternative will be developed? By the way, today's CFLs have a lousy power factor. It doesn't affect the residential electricity bills, but it does affect the utilities. Speaking about a safe alternative. If you are interested in $10 million cash, the US Dept. of Energy is offering this prize to create a solid-state screw-in replacement for the 60W bulb. If you can develop sufficiently bright LEDs and handle the packaging, give me a buzz- I would handle the AC-DC part of it, and we'll split the prize :-)

How to Measure Efficiency of a Multiple-Output Power Supply

On March 27, 2009, the US Department of Energy (DOE) published an amendment to its test procedures for battery chargers and external power supplies (EPS). The amendment includes provisions for measuring standby mode and off mode energy consumption and adds a test procedure for testing switch-selectable external power supplies. Since the document basically clarifies existing test procedures, which DOE originally could not formulate clearly, it is mainly clerical and would not be worth noting if not for one funny thing. The amendment still does not include a test procedure for multi-output power supplies because of "the number of stakeholder comments and the limited timeframe for this rulemaking." OK, here is a little background. The Energy Independence and Security Act of 2007 (EISA 2007) set Federal efficiency standards for certain types of adapters and single-output EPS for consumer electronics. DOE has a test procedure to verify this efficiency. However, this procedure [which is basically: multiply output volts times amps and divide by the input power under various loading conditions] was written for single-output power supplies. It has therefore left out a significant group of products, powering applications such as radio transceivers, video game consoles, and printers. On August 15, 2008, DOE proposed a procedure for the testing of multiple-voltage external power supplies. On page 6 of the Proposed Rule we read: "DOE is not aware of any existing test procedure developed specifically to measure the efficiency or energy consumption of multiple-voltage external power supplies." Huh? Millions of multi-output power supplies both external and internal including PC PSUs are being built around the world and tested for Energy Star® and 80 PLUS® efficiency compliance. Folks, how about this: take a 5th grader, ask him/her to add up volt-amps of all outputs, divide by the input power, and you are done! Seriously, the main obstacle for DOE seems to be the loading profile. The PSU's nameplate power is often smaller than the sum of the nameplate power of each individual output. So what's the big deal? Derate (scale down) the loads of all the outputs proportionally, so that their sum does not exceed the limit for the entire power supply. Of course, it would not be the worst case efficiency (which you would probably encounter if you shift the bulk of the load onto the lowest voltage outputs), but it would be kind of typical efficiency. Back in 2006, at the APEC conference, EPRI Solutions and Ecos Consulting presented their Enhanced Proportional Allocation Method for Loading Power Supply. Their method is incorporated by Intel in its PC power supply guides. DOE did propose to adapt the ‘‘proportional allocation’’ method. Nevertheless, the latest DOE 2009 final rule reads: "Due to the limited time provided by EISA 2007 and limited resources available prior to the publication of this final rule, DOE was unable to address the large number of stakeholder comments received and decided to defer action on multiplevoltage EPSs to a 2009 rulemaking." In a private sector usually a new power supply will be designed, built and tested in this timeframe or in a shorter one. It's entartaining to watch how long will it finally take for US DOE to make up their mind on how to test the efficiency and to move to something else.

California Emission Standards

President Obama has directed EPA to re-examine whether California and other states should be allowed to set their own auto emission standards that are tougher then federal standards. New EPA administrator Lisa Jackson was quoted as already saying she would “very, very aggressively” review CA’s application.
For reference, the 2007 U.S. Energy Bill raises mileage standards to 35 MPG and reduces CO2 emissions from autos by 30% by 2020. The California regulations require car makers to meet the same standards, but four years earlier- by 2016.

Of course, the reduction of air pollutions is long overdue – we all need this. However, allowing individual states to set standards tougher then federal ones is simply illogical. If Obama and EPA believe that meeting CA regulations by 2016 is technically possible and economically feasible, why not simply incorporate CA standard into a national standard? If CA's timeline is doable, why not to enforce it nationwide to sooner reduce the emissions in all states?
Since Obama and EPA did not state their intention to harmonize national standards with CA regulations, they apparently are not so confident that the automakers can meet CA's timetable. Indeed, it was estimated that implementation of the original federal rules by 2020 would cost the auto industry $115 billion. It would cost even more to meet these rules four year sooner. Where are US car makers going to get this additional money when they need billions of dollars just to stay afloat? Proponents of accelerated regulations say the automakers are in trouble because they don't make competitive cars. This is partially true. However, right now people don't buy enough cars not because the cars don't meet particular emissions and not even because they don't feature particular mpg. We already have high mpg hybrids. Right now, the reason why people are not buying cars is that they can't afford them, or can't get a loan. Besides getting car loans flowing again, the only thing that could boost car sales and revive the industry at this moment is lowering the upfront cost for the buyers. IMHO this would require freeze on all new regulations and of course, concessions from the unions. Note that according to GM's Vice Chairman Lutz, the CA waiver would add to the cost of the cars $4,000 to $5,000 on average. And at $2/gal, going from 28mpg to 35mpg will save us only $1429 over 100K miles.

But maybe California Air Resources Board (CARB) knows what it is doing? Well, the outcome of another California emission regulations -- the regulation of off-road engines [that particularly included emergency electric generators] is worth noting. When CARB began introducing these regulations, the Diesel Technology Forum, a non-profit educational organization, warned that when real lives are at stake and businesses are at risk, this is not the time to try to impose more stringent limits on emergency generators. CARB did not listen. They must have thought that once a regulation is enacted, the compliant products will magically appear. Not so. If you browse generators' for sale sites, you will see that many residential generators in the US market still state "not CARB-compliant, not for sale in CA." If EPA will accept CA emission waiver, a similar thing may happen with cars. Some automakers or some models may meet the new standards by 2016 and some might not. As automakers warned, they would have to produce two sets of vehicles (assuming they will not go belly up). As a result, residents of CA and those states that join them may experience a shortage of the new cars. This would additionally drive their cost up besides those extra $4K-$5K.

Everything has an appointed season, and there is a time for every matter. A time to enact regulations and a time to freeze regulations; a time to reduce emissions, and a time to reduce the cost...

First Generic Power Supply Standard

Despite the fact that practically every electronic device needs a power supply unit (PSU), the power supply requirements have not yet been standardized. Although some industries do have power supply standards (such as PICMG spec 2.11 for CompactPCI Power Interface and Power Supply Design Guide for Desktop PCs), these standards are for specific applications and do not have general usage.

IPC standard IPC-9592 is the electronic industry's first attempt to come up with a generic power conversion standard. The draft was initially developed by the IPC Power Conversion Subcommittee that included Dell, IBM, Lenovo, Hewlett Packard, Cisco Systems, Alcatel Lucent and Apple. This document standardizes the performance parameters for power conversion devices for various applications such as computers and telecommunications. It sets the requirements for design, qualification and conformance testing, manufacturing quality processes, and regulatory requirements. The document particularly lists applicable EMI standards and provides components derating guidelines. Although this standard is not mandatory (just like all IPC standards), due to the participation and support of major power supply users, one can expect its widespread acceptance.

In preparation for the standard release, IPC is planning a conference on November 6, in Irving, Texas, to discuss the details of the specification and outline the ideas that went into developing this standard.

Note that unlike Intel's Computer PSU Guides, IPC-9592 does not include any functional requirements such as voltages, currents, timing, connectors, etc. This is actually good for us, power supply designers. If our fellow digital engineers and system integrators would come up with a scalable power supply standard and would design their systems around standard PSU "bricks", OEM power supplies would become a commodity and would be primarily designed and built in the Far East. As a result, many of us designers, would have to become salespersons. But for as long as our fellow engineers choose to design their systems the way they please and then look for a custom PSU because their electrical and mechanical requirements can't be satisfied by off-the-shelf models, we, designers are in business. (-:

Efficiency Standards for Power Adapters

In a previous post I wrote about various programs and regulations aimed at increasing power supply efficiency.

Here is a brief update. On December 19th, 2007, the Energy Independence and Security Act of 2007 (EISA 2007) that is intended to reduce US Oil Dependence, became law. Although the act is aimed mainly at improving vehicles fuel economy and increasing the production of clean renewable fuels, it contain sections that affect power supplies.
Particularly, Section 301 External Power Supply Efficiency Standards establishes energy conservation standards that take effect on July 1, 2008 for so called “Class A External Power Supplies,” and establishes the processes to review and possibly amend those standards.
The term "class A external power supply' means basically a single output low-voltage AC-AC or AC-DC converter under 250W that is intended to be used with a separate end-use product.
According to this law, a class A external power supply manufactured on or after July 1, 2008 should meet specific efficiency standards depending on its nameplate power Po. For example, in the power range from 1 to 51 W [which is typical for most adapters] if you convert EISA requirement into percentage, the minimum efficiency in active mode should be 50% + 9*Ln(Po), where Ln(Po) is natural logarithm of the nameplate output power.

EISA 2007 requires US Depratment of Energy to issue a final rule prescribing energy conservation standards for battery chargers, if technologically feasible and economically justified, by July 1, 2011. DOE will also have to complete the determination on non-Class A external power supplies by a new deadline of December 19, 2009.

Note that unlike voluntary Energy Star® and 80 PlUS® programs, the above requirements are mandatory.