As the national grid becomes increasingly stressed, attention is turning back to a distributed energy structure that may be better able to deliver reliable, efficient power. Spurred by events like Hurricane Sandy, microgrids — independent, decentralized power systems — are becoming a hot topic.
At their core, energy microgrids on government installations reduce reliance on an increasingly frail external power supply, improve energy reliability, and contribute to self-sustainable operations. They help protect against typical power outages caused by downed power lines, grid failure and human error, as well as more malicious threats to supply such as terrorism, hacking and potential cyber attacks.
But microgrids do have their own associated risks. As a finite source of power, microgrids are vulnerable to energy fluctuation, and unusual demand may overwhelm the system.
While more efficient buildings, vehicles, and processes work to address demand, energy microgrids are helping to ensure access and availability by reducing dependence on external power supplies. The military is committed to responsible energy use and reducing its carbon footprint, but it is even more critical that an installation’s key systems ensure reliable power delivery under all circumstances to sustain necessary, advanced operations.
Army Maj. Joe Buccino, spokesman for Fort Bliss in Texas, explains that microgrids are essential to the future of military energy security. “The tactical utility of this technology is its ability to allow us to operate off the grid. We are entering an age of emerging threats and cyber warfare. We are assuming an unacceptable measure of risk at fixed installations of extended power loss in the event of an attack on the fragile electric grid.”
Lighting control systems, when properly planned and implemented, can create significantly greater flexibility within a microgrid. Integrated dimming control allows the facility to reduce lighting energy use on demand, leading to greater confidence in the microgrid’s ability to supply necessary power and keep essential buildings or areas operational running during natural disasters, military operations and other emergency situations.
Depending on the type of security threat, preset lighting scenarios can be programmed to react to a variety of crisis situations, ensuring that the right lights always have power. For example, a system might increase lighting levels at the perimeter, maintain full lighting power in a medical facility, or ensure lighting to emergency exits and staging areas for first response, while reducing light levels in all non-essential areas. Balancing lighting energy helps to assure the efficacy of the microgrid’s power supply.
Strategic planning and carefully defining appropriate, preprogrammed lighting control responses allow lighting control systems to work in concert with microgrids to address power generation as well as demand-side control for both everyday and emergency operations. Smart systems reduce error, improve performance and limit potential problems during an emergency.
A prominent example of energy-efficient design is The National Training Center at Fort Irwin, California. It currently uses energy-saving lighting control technologies and total light management strategies in dozens of buildings, reducing lighting energy use in these spaces by more than 35 percent. Implementations of the control protocols are now planned across the base, allowing the Army to closely monitor energy use.
Long-term planning is the key to effective implementation of a comprehensive microgrid lighting control solution. Typically, large installations need to implement lighting control upgrades over time, not all at once. The best way to achieve this is to define a lighting control strategy that will meet the goals of the smart grid in three to five years and then space out smaller retrofit projects over time, starting with the most critical buildings.
Especially in the case of large projects, it is not realistic to try to implement the entire system all at once. A multi-phased approach to lighting control implementation also allows an installation to take advantage of various funding mechanisms, the simplest of which is to add lighting controls to whichever building renovation projects are currently underway. A key advantage in securing funding, is that lighting controls save energy, ensuring that many retrofits can be accomplished using an energy savings performance contract (ESPC), a utility energy savings performance contract (UESC), or can even qualify for Defense Department energy conservation investment program (ECIP) funds.
Lighting control is often overlooked in strategic plans despite the fact that lighting is typically a building’s largest electricity consumer. Lighting control systems that incorporate automatic control strategies will often deliver lighting electricity savings of 60 percent, effectively reducing total building electricity by 23 percent.
Digital fluorescent dimming ballasts, or LED drivers, can be used to reduce maximum light levels in a space by 30 percent or more, and yet the difference is virtually undetectable to building occupants. Another benefit of digital control is the ability to quickly repurpose or reconfigure a space without expensive, time-consuming rewiring. Depending on the selected system, reprogramming can even be achieved in real time from a smartphone or tablet.
Occupancy/vacancy sensors work to ensure that lights are not left on when a space is vacant, generally saving 20 to 60 percent. Installing sensors can be an inexact science, and fine-tuning is often best performed after the space is fully occupied. For larger installations, consider a manufacturer who offers a sensor layout and tuning service to ensure that the provided sensors are installed and calibrated to perform as intended.
In perimeter spaces, sensors can be used to automatically adjust light levels based on the amount of daylight in the space. Daylight harvesting can be used to automatically contribute 25 to 60 percent lighting energy savings. In many cases, additional energy saving can be realized when decreased lighting load also lead, to a reduction in HVAC use.
In occupied buildings, one of the challenges of a lighting upgrade is the disruption to space occupants, and the high cost of renovation including the cost of new wiring, conduit and labor. Significant advances in radio-frequency-based lighting control systems make wireless controls a cost-effective, labor-saving option that causes almost no disruption to building occupants. Wireless controls can be installed and programmed quickly, with no new wiring, and can be moved easily when a space is repurposed.
When selecting a wireless control system, look for one with a history of reliable RF performance over time. One measure of reliability is to choose a wireless system that operates in portions of the RF spectrum that are less crowded and promises a lower chance of interference. The system should also offer a wide variety of control devices, proven to operate successfully in varied conditions over time. These steps will help ensure the system is robust, reliable and ready to respond.
NASA’s Propellants North Administrative and Maintenance Facility at Kennedy Space Center is another example of how these simple strategies can be used to reduce electricity demand.
The NASA team focused on a building solution that can be easily measured and broadly applied, and does not take time away from the essential work in the facility. Frank Kline, a NASA project manager, highlights the impact of lighting control systems on his ability to meet project goals. “A key to achieving net zero energy is reducing the energy consumed by the lights in the facility. The lighting system saves a lot of energy without requiring building occupants to put any thought or effort into helping do so.”
Microgrids commonly work in concert with grid-based energy sources to provide essential energy generation during normal, day-to-day operations. During emergencies, or other situations that require the microgrid to supply all essential electricity, lighting controls can be programmed to shed load for maximum system efficiency, as part of an identified demand response protocol.
Demand-response strategies that focus on lighting control allow a facility to respond to load-shed requests automatically or at the touch of a button, ensuring that essential resources can remain focused on other operational priorities. An integrated lighting control system can incorporate load-shedding software to quickly and easily reduce the lighting load to a pre-programmed level. The overarching goal of demand-response is to keep the electricity supply at a steady and controllable state while meeting the requirements of the facility, and not exceeding the capacity of the microgrid.
Microgrids represent a move toward greater energy safety, security and independence for the military, and ultimately, for everyone served by the increasingly stressed power grid. According to some estimates, the microgrid market is projected to grow to $40 billion annually with the majority of it occurring in military, education and public works facilities. Lighting control is a key component in achieving microgrid success. Andy Wakefield is director of government and OEM solutions at Lutron Electronics. Credit: Lutron Electronics