Directives drive efficiency

There are many reasons why engineers would want to design new energy efficient electrical products. One concerns global warming: worldwide legislation is requiring more energy efficient designs. The European Union (EU) has adopted the Ecodesign of Energy using Products (EuP) Directive, but the US, Australia and many other countries have legislation covering a variety of products. Energy efficient design is not new. This can clearly be seen in portable battery powered products that have been designed to last as long as possible between charges – mobile phones are a good example. Customers require small, lightweight products with greater functionality and longer battery life. Manufacturers have clearly achieved these aims, but this has required huge technology changes in phone and battery design. These changes have included: * Change from nickel-metal hydride to high capacity lithium-ion batteries * Active power management to switch off functions not being used * The use of lower voltage circuits: if voltage can be reduced from 3 to 1.5V, this halves power consumption. * Low power consumption components, designed to operate in active and standby modes, consume less than 1mA in active mode and even less in standby * Combining functions on ics. Modern mobile phones contain fewer chips than 10 years ago, but have many more functions These types of design change can be used in any type of electrical product, not only portable items such as laptop pcs and pdas. However, each type of product requires consideration of particular issues. The following examples are products that are, or will soon be, covered by EuP implementing measures: * Televisions. In modern tvs, most energy is consumed by the display. LCDs can be more efficient than plasma display panels, but the way in which these operate influences energy consumption. If PDP pixels are switched off to show dark areas, then these use little power whereas the fluorescent backlights of LCDs consume power continuously. LCD lamp efficiency can influence power consumption, although a recent trend to use lower efficiency lamps has improved colour quality. The most significant energy improvements will be achieved by adopting new energy efficient types of display. Several manufacturers have launched new tvs which have LED displays that consume less power than LCDs. These new displays are also increasingly used for laptop PCs as they give much longer battery life, mainly because there is no need to generate the high voltages needed to operate fluorescent backlights. Other novel display technologies being developed include OLEDS (organic LEDs). The TV EuP implementing measure requires that tvs switch automatically to a standby mode if no user interaction occurs during a four hour period, which assumes that after four hours, no one is watching! * Refrigerators. The EuP implementing measure imposes a maximum energy efficiency index (EEI) on refrigerators and freezers. To achieve this, insulation is clearly important. Most energy is consumed by the compressor motor and so its energy efficiency is important in achieving a low EEI. * Set top boxes. These have developed very rapidly with little consideration of energy efficiency. However, energy efficient design is being imposed by an EuP implementing measure that specifies maximum power consumption values for each function. Achieving reduced power consumption is not straightforward as set top boxes are complex electrical products. Minimising consumption of each function is required, but this must not affect performance or compliance with other legislation such as the EMC Directive. * Electric motors. Because motors are used in a wide range of applications, they are one of the largest consumers of electricity. An EuP implementing measure has been adopted that imposes limits on the energy efficiency of motors that can be used. From 1 January 2015, all motors from 7.5 to 375kW (from 0.75kW in 2017) must be IE3 unless they are used with variable speed drives. In this case, less efficient IE2 motors may be used. IE2 and IE3 are defined by EU regulation 640/2009. Electric motors coupled with variable speed drives (VSD) give much better energy efficiency overall but VSDs are not suitable for small low power motors or applications where space is very limited. Under these circumstances, more efficient motors are required. There are also two 'horizontal' EuP implementing measures that affect a range of products and need to be considered by design engineers. Standby and off mode This legislation includes household appliances, consumer products, toys and leisure equipment, as well as IT and telecom products intended for use in primarily domestic environments. Products that are in scope will need to meet maximum energy consumption targets when in standby or off mode and be able to switch to an off-mode or standby mode from September 2009 (maximum 1W or 2W if there is an information display). This will be required unless 'inappropriate' for the product, such as for safety reasons. In this case, the reasons must be explained in the product's technical file. From September 2013, the maximum energy consumption in standby and off modes halves and it will be necessary to include a power management function that switches the product into standby or off mode automatically. This should be after the shortest time that is reasonable for the product. The specific implementing measure for tvs has set this time at four hours. Some manufacturers have already adopted highly innovative designs and can meet the maximum standby mode power loss limit; others will need to make significant design changes in order to comply. External power supplies Millions of external power supplies are sold annually in the EU and will be covered by this legislation. There are exclusions, including battery chargers, but if the power supply unit is used to power the product as well as charging its battery, then these will be in scope. In the EU, only power supplies intended for consumers are in scope, but similar legislation in the US and Australia includes all power supplies. The regulation imposes a maximum power consumption limit when disconnected from the equipment (initially 0.5W) and minimum energy efficiency. This regulation will mean that switch mode power supplies will need to be used as linear power supplies will not meet the requirements. Switch mode power supply design and energy efficiency varies; some products are far better than others. Energy efficiency is influenced by the circuit design, selection of components and the construction of the transformer. The maximum power consumption and efficiency limits of most EuP implementing measures are based on 'benchmark' products – the best available on the market. Some manufacturers of electrical products adopted policies many years ago to develop equipment with energy efficiency as a high priority. Although this was originally seen as a marketing aid, it pre empted future legislation and has enabled those companies to meet new legal requirements easily. In the future, it will be advisable for all manufacturers of electrical equipment to consider energy efficiency when designing new products.