The Importance of Thermally Managed Enclosures
Many utilities rely on communications sites located in remote areas with little supporting infrastructure. Much of this equipment, including backup batteries, requires protection from the elements. Thermally managed outdoor cabinets are a cost-effective way to protect batteries and sensitive electronics and keep them performing at their peak in rugged, outdoor environments.
By George Brendahl, Marketing Manager, Utilities and Nuclear, EnerSys®; Zac Slovarp, Marketing Manager, Enclosures, EnerSys®
Many utilities rely on communications sites located in remote areas with little supporting infrastructure. Much of this equipment, including backup batteries, requires protection from the elements. Thermally managed outdoor cabinets are a cost-effective way to protect batteries and sensitive electronics and keep them performing at their peak in rugged, outdoor environments. Following are some considerations for assembling the right battery and enclosure system for today’s remote utility sites.
Surviving Remote Locations
Remote locations are often inaccessible, yet must remain reliable despite grid instabilities. A hybrid approach — such as one involving generators, renewable energy sources and batteries —can help keep the network running. Batteries used in these applications must recover quickly and survive Partial States of Charge (PSOC), harsh weather and extreme temperatures. Keeping batteries at their optimal temperature range helps ensure reliability, high performance and long life, while maintaining low operating expenses.
Optimizing Energy Storage
Utility companies that are using batteries to ensure reliable service want batteries with higher cycles, quicker recharge rates and longer life.
In response, some manufacturers are building new eco-efficient enclosures with no additional cooling. While this reduces costs, it subjects the battery to higher temperatures. Meanwhile, utilities with older cabinets may seek the same efficiencies by reducing run time on air conditioning. Both scenarios underscore the need for temperature-tolerant batteries.
Some battery manufacturers are turning to specialized manufacturing processes to develop batteries that reduce ownership costs, while enhancing battery performance. Advanced lead acid batteries with Absorbed Glass Mat (AGM) construction and Thin Plate Pure Lead (TPPL) technology offer roughly 30 percent more power density and 11 percent more energy density versus similarly sized Valve Regulated Lead Acid (VRLA) batteries. TPPL technology also yields a shelf life of up to 24 months without a charge, compared to six months for a traditional lead-calcium battery. Batteries with TPPL technology also are less likely to fail in extreme temperatures and can be used from -40 to 122 F.
These features make batteries with TPPL technology ideal for unattended locations with little or no climate control, providing tremendous reliability and reduced ownership costs.
While some batteries may be more temperature tolerant than others, all batteries in remote locations can benefit from the protection of a thermal-controlled enclosure.
Many factors affect the thermal performance of an outdoor cabinet, including:
· Range of seasonal temperatures,
· Thermal load produced by the sun, and
· Thermal load produced by the active equipment and components deployed inside.
In many installations, the thermal management system can have the largest impact on operational expenses at the remote site.
Today’s manufacturers offer a range of technologies and capacities to match the user’s thermal management requirements. Users must weigh their options based on technology, performance, reliability and cost.
Security and Intrusion Prevention
Security is a critical concern today. Unauthorized access to equipment can result in loss of or damage to valuable assets and possible network downtime, reduced service revenue and unsatisfied customers.
Features that can enhance security include:
· Concealed door hinges;
· Captive door latches that can withstand serious torque, are inaccessible to external tampering and stay in the locked position;
· Intrusion-proof frame with protective interior flange; and
· Intrusion alarms.
Expandability and Flexibility
Enclosure systems should be designed to accommodate changing application needs and various environments. This enables the operator to standardize on one enclosure model, while allowing for different equipment configurations and deployment challenges. Features such as additional equipment bays, power and battery backup and thermal management capacity ensure that the cabinet will meet deployment demands today and tomorrow, without resorting to expensive custom development.
For large-capacity applications, dual bay battery cabinets provide additional flexibility for backup power, energy storage and uninterruptable power systems.
Remote sites are a fact of life in the utility transmission and distribution network, and although they are out of sight, they can have a significant impact on a utility’s operating budget. In today’s market, a backup system leveraging advanced lead acid batteries with TPPL technology offers the best of all worlds, providing rugged construction, optimum power and long life. Incongruously, while utilities largely strive to keep pace with the latest battery technology and electronics, they often fail to protect their investment by fielding the thermally managed enclosures necessary to keep them operating at peak efficiency. The good news is that today’s operators have a wide variety of enclosure options available that can be tailored to specific needs and budgets, making it possible to develop an ideal solution for any installation.
EnerSys, the global leader in stored energy solutions for industrial applications, manufactures and distributes reserve power and motive power batteries, battery chargers, power equipment, battery accessories and outdoor equipment enclosure solutions to customers worldwide. Motive power batteries and chargers are utilized in electric forklift trucks and other commercial electric powered vehicles. Reserve power batteries are used in the telecommunication and utility industries, uninterruptible power supplies, and numerous applications requiring stored energy solutions including medical, aerospace and defense systems. Outdoor equipment enclosure products are utilized in the telecommunication, cable, utility, transportation industries and by government and defense customers. The company also provides aftermarket and customer support services to its customers from over 100 countries through its sales and manufacturing locations around the world.