Note: Second in a series on energy solutions.
The demand for wireless coverage has led to the rapid proliferation of cell sites. It should be no surprise that an estimated one million cell sites exist globally and new sites are being installed every day. The thirst for coverage and data are growing beyond our wildest dreams. For example, India has added as many wireless subscribers in the last four years as the entire population of the United States.
The increased demand for bandwidth and coverage has also increased the energy required to run these sites. That also means an increase in an operator’s expenses.
A typical wireless cell site has radio and backhaul equipment, rectifier power supply and batteries. Often this equipment is housed in a shelter. The inefficiencies associated with this equipment are dissipated as heat. Most cell shelters rely on traditional air conditioning units to cool the equipment and maintain temperature, usually below 25 degrees Celsius (77 degrees Fahrenheit), ensuring optimal life and performance for the batteries. Depending on the climate, the energy cost of operating AC could be 30 percent or more of the site’s total energy costs.
There is an easy way for operators to reduce their cooling energy costs. CommScope’s shelter cooling solution works in conjunction with air conditioning and reduces its operational time. When the outside temperature is below the temperature setpoint in the shelter; it turns off the air conditioning and brings in the outside air for cooling. A variety of options are available to filter the outside air of contaminants and moisture. When the outside temperature is above the temperature setpoint in the shelter, the shelter cooling solution turns off and the air conditioning unit is operational. CommScope’s shelter cooling solution uses variable speed DC powered fans, which minimizes its energy consumption to afew hundred watts.
Shelter cooling solutions have been installed in the United States (Boston,Kansas City, and Dallas), Colombia (Barranquilla) and Nicaragua (Managua). Field data from these installations has demonstrated that the shelter cooling solution saves about 75 percent of the cooling energy costs.
Most radio and backhaul equipment in the shelter is rated to operate in temperatures in the 35 to 40 degrees Celsius (95 to 104 degrees Fahrenheit) range, while the batteries must be maintained close to 25 degrees Celsius (77 degrees Fahrenheit). As an option, CommScope provides a thermo-electric cooling kit, which customers can install to maintain the battery temperature at 25 degrees Celsius (77 degrees Fahrenheit), while the temperature in the shelter can be raised higher, thereby increasing the energy savings achieved by the shelter cooling solution.
The cost savings are dependent on the climate, equipment heat load and per-unit cost of electricity. Typical savings at the wireless cell site are in the range of $1,000 to 2,000 per year. For a 1000 site deployment, this would equate to $1 million to $2 million in energy savings and equivalent reduction in carbon dioxide emissions from the power plants producing the electricity.
In conjunction with CommScope’s OneBase InSite® Connect remote monitoring solution, an operator can monitor and control environmental conditions of an entire network, including temperature, humidity levels, power usage, backup status and more from the site. The combination of cooling efficiency and real-time control takes operational savings to a whole new level, reducing truck rolls and fossil fuels costs.
What energy challenges in your network keep you up at night?