The term “green telecommunications” is tied closely to the reduction of the energy consumption by a telecommunications network. A distinction is made between direct and indirect energy costs. The direct energy consumption is a consequence of operation of the telecommunications infrastructure: the telecommunications systems, including the OSS, BSS, and air conditioning, are the greediest consumers. The indirect energy consumption comes during operation of the office buildings – PCs, lighting, heating, air conditioning – and from the car fleet, e.g., sales representatives and maintenance.

Green savings potential

Energy savings typically mean also cost reductions. So cost pressures for network operators favor green telecommunications as a general principle. However, the exploitation of the savings potential from operations requires investments in most cases – the purchase of the latest generation of telecommunications systems and air conditioning equipment, for instance. The resulting savings in energy often do not justify the investments. That is why the older equipment is generally not replaced until the systems and devices have reached their end-oflive; at the latest, however, this happens when operating security is no longer guaranteed and the risk of system outages rises significantly. The typical lifecycle of these systems is ten years, sometimes even more.

If solely economic aspects are used as the basis for a decision about replacements, there is no guarantee that the most energyefficient variant will be selected. In such cases, the calculation of the total cost of ownership shows that the energy savings, even over the entire lifecycle, will not compensate the higher investment costs. Programs for energy conservation mandated by political regulations can have a supportive impact in these situations.

However, green telecommunications can also mean buying green energy or generating energy oneself. Comparatively higher costs must be expected for the purchase of green energy. The utilization of solar or wind energy requires additional investments. But this approach is moving ahead at a fast pace in countries where there is a lack of full-area availability of electric power. A diesel generator is replaced by solar energy and serves solely as a backup, for example. Energy savings in field service can be achieved by optimizing assignments with respect to travel time. Reducing travel time also reduces fuel consumption. The reduction of the travel time by calculating shorter routes not only has the benefit of conserving energy, but also increases work efficiency. Travel time is “idle time”, and by increasing the number of productive assignments per day, we also increase efficiency. The distribution of field technicians over the area is one prerequisite; an increase in the number of potential destinations per area unit is a second. Practically speaking, this means a broadening of expertise of field technicians so that they are able to work with a number of technologies rather than being limited to a single one. Additional savings result from the modernization of the vehicle fleet and the swap to more economical vehicles. Energy savings on the one hand are offset by the network expansion on the other. A growing network can eat up the savings so that the bottom line does not show any savings; but at least the energy consumption does not continue to increase. So energy efficiency cannot be measured by absolute consumption; we need the definition of a suitable measuring unit in the sense of efficiency = expenditure / effect.