Conserving energy

The broadband DSL access network consumes about 20 billion kilowatt-hours of energy per year worldwide (equivalent to four percent of Germany’s annual energy consumption). A large amount of this can be saved in a simple step.

At present, broadband access always runs on full power, but the L2 mode could reduce the transmission output of the system and therefore its power usage during quiescent communication. While this mode is available it is often not used as it causes interference to neighbouring DSL systems.

When a modem connects to the Internet while neighboring modems are still in L2 mode, only a small degree of interference occurs and the data transmission rate is high. If, however, systems in neighboring houses or apartments become active, the interference to the first system is so great that the connection crashes and the modem can only go online again after a prolonged restart phase.

But now scientists at the Fraunhofer Institute for Communication Systems ESK have found a way around the problem by using artificial or virtual noise to stabilize DSL connections so that L2 mode can be deployed. The artificial noise simulates typical cable bundle interference to the broadband receivers.

Network operators can reduce their electricity consumption by several million kilowatt-hours per year. At a later stage, users too would benefit.

Engineers have developed a technique that saves energy and servicing costs by indicating when air conditioners are low on refrigerant, preventing the units from working overtime.

The new "virtual refrigerant charge sensor" is particularly practical for automotive air conditioners, which tend to leak refrigerant more than other types of units, and also for household central air conditioning units.

Maintaining the proper amount of refrigerant in a system, saves energy because air conditioners low on refrigerant must operate longer to achieve the same degree of cooling as properly charged units.

The research has been funded by the California Energy Commission through its Public Interest Energy Research, or PIER, program. Taking this further, a software algorithm was developed that interprets temperature-sensor data to estimate the amount of refrigerant in the system.
The method could be commercialized if a company invested some time in the implementation side, according to the team.

The savings can be lots. When energy is scarce, and sources shrinking by the day, every pinch saved means releasing more for other needs. It has been shown that retrofitting a home with efficient lighting and heating can involve an initial cost of Rs 30,000 but in the long run can bring around Rs 24,000 savings every ten years.

One unit of power saved is equivalent to three units generated. Right?