GreenEdge Blog
Power System Requirements for Energy Efficiency
Today a significant amount of energy is wasted in power conversions, as we consume it. The conversion of power from one voltage to another has inherent efficiencies of conversion resulting in wasted energy. The higher the efficiency, the less wasted power. Significant energy savings can be achieved by not only having high efficiencies at full loads, but also by maintaining high efficiencies at light loads with low standby power and ON/OFF power controls via remote networked managed systems.
Today power supplies consists of discrete PWM controllers and regulator, creating a “bag of chips” for a multi-rail power supply as seen below, with multiple conversion stages and varying efficiencies.
Figure 1: Typical Multi-rail Power Sub-system
These discrete solutions are extremely difficult to manage and control in order to achieve next generation energy conservation solutions. As we can see from the design, there is no end-to-end cohesive System Energy Management solution. The reason is quite obvious, each power controller has to be independently controlled across an isolation boundary and synchronizing and sequencing these controls can become extremely challenging and costly.
Power supplies need to respond to changes in the environment e.g. light, occupancy, time of day usage cost of electricity etc. They need to be able to connect to low cost sensors like ALS (Ambient Light Sensors) or Proximity Detectors and provide autonomous control thus achieving huge energy savings. Some examples are lighting controls for adjusting power supplies usage for daylight harvesting, or the use of washers and dryers during peak hours through Demand Response. Power need to be networked to be able to enable remote control and management, for example home/office temperature or lighting control via computers, smart phones like iPhones, Blackberry’s etc.
It’s time for the next generation Smart Power Supplies for Autonomous Energy Conservation – what do you think?
Printer-friendly versionThe Need for Energy Conservation
Today a significant amount of energy is wasted in power conversions. Conversion of power from one voltage to another, while a necessity in power distribution and usage, has inherent conversion losses resulting in wasted energy. Higher conversion efficiency results in lower amount of wasted power, and this affect is multiplied if several conversions are used to create a required voltage. Significant energy savings can be achieved by not only having high efficiencies at full loads, but also by maintaining high efficiencies at light loads, low standby power and adaptive power controls via remote networked managed systems
The list of electrical appliances we use in our everyday life continues to grow: IP Phones, IP Cameras, Settop/DSL modems, HVAC heating and cooling systems, TVs, Washers & Dryers, Lighting etc. A lot of these appliances operate for a significant amount of time at light load power, between 20-50% of full load. With Digital Power Control techniques, it is now possible to adapt switching nature of power converters to optimize light load efficiency. This can be done locally by monitoring loading conditions or by remote network commands based on network policies.
Power supply designs should achieve as low as possible no load power consumption, as equipment that is on standby will consume this power 24x7. At present international standards require a no load power consumption of less than 1 Watt. ENERGY STAR® Small Network Equipment (SNE) is now driving a new standard for Small Network Equipment (SNE) to reduce standby power to less than 0.5 Watt. Further information can be obtained from the EnergyStar website.
The largest energy savings can be achieved through Network Managed Power - using networks like Ethernet, ZigBee, DALI, LoPower WiFi etc. Network connection to power subsystem enables intelligent monitoring and adaptive control from any remote location, allowing appropriate energy management policies to be pushed to each appliance as necessary.
It is said that the key to energy savings is the ability to measure, monitor and control the power supply--what do you think?