In the early 1990s, small, regional telecom companies began to consolidate and evolve into the large regional and national carriers we see today. As the business landscape evolved, so did customer demands. Telecom companies reliability became critical after September 11 and an extremely active hurricane season in the early 2000s, which included Hurricane Katrina. During this time, telecom companies discovered how much their consumers depend on and expect uninterrupted mobile service during emergencies.
The reputation of cell phone tower’s standby power and service providers became a critical selling point. Telecom companies also started seeing consumers eliminating their home phone line and relying solely on cell phones to communicate with friends and family—especially during emergency situations. mtu’s industry-leading reliability has helped telecom companies meet their customers’ demands and expectations for flawless mobile service, helping mtu quickly grow its client base from hundreds to thousands.
“mtu has served one of the largest wireless carriers of the Gulf Coast through several natural disasters, including the very active hurricane seasons of 2004-2005. We have nearly 2,000 generator sets along the Gulf Coast states powering wireless and other telecom services,” said Isebrand. “One of our large install base of generators served wireless carriers during Super Storm Sandy. Our telecom customers are very service oriented and demand reliability during the harshest conditions. Their customers are our customers, and we are focused on providing them the best service.”
To the benefit of risk-averse telecom companies, mtu takes a very conservative approach to designing and rating its generator sets. For example, mtu generator-drive engines are designed with more cylinder displacement per rated horsepower than alternative products. As a result, mtu generator sets are certified at an 85 percent average load factor over 24 hours, significantly higher than the 70 percent average load factor required by ISO 8528. Other generator set manufacturers merely meet the ISO load-factor minimum, which means the average load factor that can be sustained by most generator sets over an extended power outage is only 70 percent of the nameplate rating. Since mtu generator sets can handle 15 percent higher average loads than competing products, users may be able to specify fewer generator sets for data center applications, depending on the size of the installation.
When creating a custom mtu power system, the customer determines the priority for each cell site and bases the reliability requirements on highest priority. Some sites are more susceptible to outages than others. The number of generator sets a company requires depends on the individual companies different site level priorities. Some of mtu’s customers mandate backup emergency power at 100 percent of their locations (where feasible). Statistical analysis is used to determine what emergency backup power requirements are needed. Most single carrier cell towers can be sustained with a 30 kW generator. Equipment designed for indoor applications require additional climate controls, which increase the power requirement.
“The power business is very competitive. mtu excels in offering complete solutions to its customers,” said Jentges. “Our systems are made with careful custom design work manufactured precisely to the customer’s requirements.”
To protect against power blackouts, telecom company power schemes include layers of redundancy. Customers generally install generators as an open transition backup to their utility power—if there is an outage from one substation feed, the second one will automatically take over. To supplement these layers of utility redundancy, battery back-up is used for short duration outages. Battery backup is very expensive to maintain and does not last as long as a single generator set will last.