Benefits of Batteries: The Emergence of Energy Storage

Duke Battery Sundance Solar

Batteries are ubiquitous in our modern lives, in cell phones, computers, cars, clocks, toys, tools and many more applications. Yet the idea of a battery-powered home or business is likely to generate a quick laugh or a skeptical look.

Of course, there are hundreds of thousands, if not millions, of off-grid applications globally that employ batteries, but the idea of having a battery system in a conventional or even green building on the grid seems irrelevant to many. Fortunately, that perspective is changing as energy storage is being incorporated into a modern grid infrastructure, with benefits to homeowners, businesses and utilities.

The rapid pace of energy storage battery technology is getting lots of attention, from lithium ion to organic-based batteries, but instead of delving into details on how to store the energy, the focus here is why to store the energy.

There are four main benefits to having a residential or business battery system: increased reliability, addressing peak demand issues, grid stabilization and climate change.

Reliability of the power supply is very important to nearly all, and critical to some, for example those who rely on medical equipment. Power outages can last from a brief flicker of interruption to many days down. The average outage time, not counting major natural disasters, is generally only a few hours, thanks to the exceptional response of the utility line crews. Having a home battery backup system, much like a uninterruptible power supply for your computer, can avoid the disruptions of most of those outages.

If the home or business has a solar photovoltaic (PV) system, then a battery system can be recharged onsite by the sun during an extended outage. Many green builders already offer solar technology, and adding battery storage to the design enhances the options for additional, scalable backup power. Adding a new battery system to existing solar PV installations is another practical option.

On the utility scale, energy storage can increase reliability during peak demand times to avoid brown outs of localized power reductions. Energy storage options also allow a utility to flatten its daily generating output cycles and more efficiently utilize lower nighttime generating levels.

Peak power demand issues during the winter heating season are at the forefront in Western North Carolina. Duke Energy is closing its coal-fired power plant at Lake Julian and building two natural gas combined cycle turbines. Current Duke Energy peak demand projections suggest a need for yet a third natural gas turbine unless peak demand is reduced by approximately 17 MW each year for the next several years.

Since current utility planning for infrastructure revolves around the worst-case peak energy demand needs, shaving that winter peak demand saves money for ratepayers and for the utility. Among a range of promising opportunities, deploying battery storage in residential and business and utility applications can help directly to solve this challenge. Drawing power from a battery bank, rather than increasing generating output, can dramatically reduce peak demand.

Building weatherization, real-time demand response programs, load shifting, increased efficiency in heating systems, Advanced Meter Infrastructure (AMI) with two-way data exchange, solar thermal, and advanced heating and cooling systems like geothermal will also play a role. Notably, from a narrow economic perspective alone, it’s more cost effective to invest in these opportunities to reduce peak demand than in the capital cost to build a third natural gas turbine, even without including the operation and fuel requirements and costs.

Duke Battery Sundance Solar
Photos courtesy of Duke Energy.
The Mount Holly Microgrid project located in Gaston County features a Saft 650kW lithium-ion battery and a 200kW Alevo lithium-ion battery. The battery storage system is integrated into a microgrid with more than 115kW of solar panels. In addition, residential energy storage systems from Tesla and Enphase are being tested and providing valuable insights into future benefits and operational realities of behind-the-meter energy storage.

Grid stabilization is a general term for the complex utility requirements to reliably maintain the voltage, current and frequency of the grid’s power supply to customers. From the general public’s perspective, it’s likely the least compelling benefit, in large part because the grid is currently so successful at being stable.

Nearly a century of development and operation of a centralized power grid system has resulted in a conventional grid infrastructure that is overall very reliable and stable. Central power sources (whether large hydro, coal, gas or nuclear) that feed into thousands of miles of transmission lines carrying megawatts of one-way electricity to millions of end users are marvels of technology and engineering.

However, the rapid expansion of distributed energy sources, primarily solar and wind energy, changes the engineering equations and presents new challenges for energy distribution and voltage, current and frequency stabilization over the grid. The good news is that long-overdue new investments and upgrades to our aging grid infrastructure are underway, with Duke Energy alone committing billions to a wide range of grid-improvement projects.

Obviously the technical aspects are very complex, however, simply stated: the timing for modernizing the grid infrastructure is right on course to incorporate not only clean energy from solar and wind sources, but additionally a wide range of distributed energy services and customer resources to support a more responsive, reliable, clean and cost-effective grid system.

Climate change is the most important reason to take action regarding our energy and resource extraction policies. Transitioning to a much lower carbon footprint and reducing environmental impacts is essential for a myriad of reasons. Suffice to say, climate change is established science.

There is no single silver bullet to solve the problems of climate change; rather, the answers lie in a comprehensive approach that primarily includes electrical generation, transportation, building science and agricultural practices (not addressed here).

Energy storage is an essential factor for reliable, stable electrical generation from sustainable sources, in addition to the rapid emergence of electric vehicles (EVs) that operate from those clean sources. In fact, EVs already intersect with both utility planning and residential applications, such as home charging stations.

Green building science is another essential element, as it integrates many strategies from high efficiency providing demand reduction to true net-zero energy design.

Much like many unseen, yet incredibly effective, energy-efficiency measures (such as attic insulation), batteries don’t have that “gee whiz techno” visual appeal of solar panels or wind turbines for most folks. However, just as efficiency measures are critical in reducing the demand for more generating capacity, energy storage is critical for managing and distributing our next generation of clean, sustainably generated powerbecause climate change matters.

Yes, there is an environmental and carbon footprint for battery systems. However, just like solar, the footprint and the economic costs are a small fraction compared to current non-renewable fossil fuel and nuclear impacts.

And just like the steep decline in the upfront costs for solar, cutting-edge battery and energy-storage costs are also beginning to see a decline. Interestingly, the traditional, time-tested flooded lead acid batteries are still the most cost effective in many energy applications, such as residential energy systems, and are virtually 100 percent recyclable.

Ongoing research and development of battery technology is crucial for higher efficiency and lighter weights and longer life cycles, however we already have the proven and emerging technologies to begin an energy-storage transition in support of clean energy generationcost effectively and environmentally responsibly.

Ned Ryan Doyle is a sustainable energy and environmental advocate with decades of experience and activism. Currently co-chair of the Energy Innovation Task Force’s Technology Work Group, he works from a personally designed and owner-built fully off-grid workshop powered by solar energy. Contact Ned at

You can also view this article as it was originally published on page 38 of the 2017-18 edition of the directory.