Hybrid energy for network power

With telecommunications networks already responsible for more than 1% of energy consumption worldwide and demand for network access and mobile broadband consistently outpacing deployment, telecom providers across the globe are searching for ways to more efficiently power and operate their networks.

To that end, Emerson Network Power is offering insight and recommendations for properly evaluating, selecting and operating smart hybrid energy solutions at telecom cell sites.

There are opportunities for improvement ranging from more precise configuration and dimensioning of hybrid systems to implementation of intelligent hybrid technologies that make hybrid solutions even more efficient and change the value proposition for some network providers.

“The hybrid market is evolving rapidly and evolving differently in various parts of the world. Providers are looking for different blends of capital and operating expenses and technological capabilities to suit specific markets,” said Wake Norris, director of product management - solutions for Emerson Network Power’s Energy Systems business.

“The emerging generation of intelligent hybrid technologies offers solutions for providers that value increased visibility and control across their networks and the TCO that comes with it, but there also are engineered best practices that can provide measurable benefits without significant capital investment.”

With that in mind, Emerson has made some key observations and recommendations to providers considering hybrid technologies or looking to maximise an existing hybrid infrastructure.

Hybrid deployments traditionally have been purchased as static hardware with a general maintenance or warranty contract only. This is an acceptable solution to minimise immediate capital spending.

However, for those operators focused on minimising medium- to long-term operational and capital costs and maximising ROI, smart hybrids with active management can aid with achieving additional savings.

Advanced analytics and remote management can deliver measurable load, environmental and performance improvements. Intelligent solutions can, for example, alert if a battery cell may be damaging an entire string or if a single dirty solar panel is reducing the output of an entire array.

They also can adjust cooling operation if load or temperatures vary, change maintenance dispatch schedules if a generator is operating less than usual and notify if fuel quality degrades.

The operational return from engaging active management, especially from a supplier with expertise in designing and configuring these infrastructure technologies, will more than pay for the incremental investment in most situations through lower fuel usage, fewer maintenance visits and an overall longer site equipment life.

Generator: Generators that are part of a dynamic hybrid energy solution are most cost-efficient when properly dimensioned and intelligently managed with the provider’s operational cost goals in mind.

A chronological on/off with an existing generator can work - but will it ensure optimal maintenance cycles, maximum battery life and efficiency or factor in sun position?

The hybrid generator solution is best engineered by factoring in these and other energy, load and site considerations and will affect the selection of generator size, alternator profile, fuel source and security measures, etc.

By actively managing a smart hybrid site, generator maintenance cycles and fuel usage can be further cost optimised as site and load conditions evolve.

Batteries: In hybrid solutions, batteries are critical elements for successful cost minimisation. Errors in battery selection and operation can be among the most costly for a provider, yet are the most common.

Selection of the right batteries (among many options for chemistry and construction) must be based on clear capital and operational goals, rather than trends.

More than any other element, batteries will benefit from active management of charge, ensuring long service life, minimal site cost and maximum uptime for the provider.

AC line conditioning: Some hybrid solutions are in areas with grid power that is either unreliable or low quality. Ensuring that proper technologies are used to protect the active devices on the site is imperative. Insulation and voltage regulation are effective and cost-efficient.

More sophisticated techniques such as phase selection, filtering, power source blending and other methods further contribute to using the grid, while not falling victim to it. Smart hybrids with active management in these environments are particularly important to reduce generator run time and ensure best charge conditions for batteries. This will minimise operational costs and extend the life of the site investment.

Solar: Solar is becoming a viable power source for cell sites around the world. Proper use of solar power begins with understanding solar intensity and seasonal variances to design sites for their unique physical conditions.

Solar also is a low-density power solution and requires the greatest space or creativity to deploy. Security and maintenance also must be considered - protecting panels from theft, misalignment and suboptimal operation due to dirt is important.

Periodic maintenance is required, but a smart hybrid system, actively managed, can minimise cost by dispatching service personnel only when cleaning or repair is necessary.

Wind: Wind is best in an array of turbines for large power delivery connected to a reliable electric grid. The scale of the utility turbines with multipoint deployment allows for cost-effective management of maintenance and wind variability.

The use of wind turbines at a cell site needs to account for community acceptance, for the ability to run unattended under all conditions and for the inevitable windless days.

For a single-point, off-grid cell site, wind is a challenging power source to be effective - for cost or energy - but it can be successful in some locations.

Fuel cells: Fuel cells are an option from an environmental point of view and there are various technologies that have been deployed successfully.

The biggest challenges to cost-effective use at cell sites are the start-up time - a battery is always necessary - and the fuel supply-chain.

Until these two items are addressed, this technology is best directed to sites with strict emissions mandates.

Ultimately, all sites are different and will require innovative solutions and engineering. With suitable research and planning, there are hybrid options that can fit urban or remote network sites and help telecom providers balance their capital expense while reducing their operational costs.

And with active management of smart hybrid systems, providers can ensure that they have not only installed the best solution, but that they will continue to reap additional operational savings as their network rapidly evolves.