An innovative photovoltaic panel system, which adheres directly to the roof membrane works well with Twentynine Palms’ 90- mph winds and 120 degree temperatures. Drought tolerant native plant materials, highly efficient irrigation system, and naturalized granite and river rock ground coverings create a sustainable landscape design. Photos courtesy of Haskell and Root Photography
The new Marine Corps Exchange (MCX), at the remote location of Marine Corps Air Ground Command Center (MCAGCC) Twentynine Palms, Calif., successfully embraces the day-to-day needs of the Marine while minimizing impact on the planet at large. This facility’s efficiency is a small step in the right direction and welcome addition to the great sustainability strides already taking place within Marine Corps Community Services (MCCS) and at Twentynine Palms.
The Mojave Desert can be a brutal place for a Marine to train and reside. MCCS realizes this. Consistently striving to improve a Marine’s quality of life is what they do. The new MCX at Twentynine Palms is one of the more recent additions to their morale boosting repertoire. While this exciting new store in the desert will certainly enrich the lives of the Marines and their families, it goes beyond that. It will enhance the lives of future generations because it was built as a sustainable facility.
This 136,000-ft² MCX provides one-stop shopping at MCAGCC Twentynine Palms. Without this new retail establishment, military families would have to drive nearly 50 miles to Yucca Valley, Calif. MCCS desired a building capable of housing a large variety of goods; a convenience store with a sizeable beverage section; a barber shop, Starbucks, GNC and other vendor spaces; and a food court with three restaurant choices.
The larger, open-floor concept at Twentynine Palms provides an organized and welcoming shopping space. From sporting goods to a Starbucks, the facility successfully embraces the day-to-day needs of the Marine while minimizing impact on the surrounding environment and the planet at large.
Much to the enjoyment of the Marines, sailors, retirees and their families, the new MCX meets every shopping need. The larger, open-floor concept provides an organized and welcoming retail space. Starbucks and the food court are a big hit with the enlisted personnel. Capitalizing on the existing desert site location, the building exterior integrates well with its surroundings. A family-friendly paver walkway creates a seamless transition between an adjacent park and recreation area. MCCS is committed to the Marines and their families, and this new facility is a fine example of that philosophy.
The LEED Gold-certified facility is integrated with an abundance of sustainable strategies and features. An analysis of various sustainability measures was conducted to compare life cycle cost with initial financial output. The project team integrated features that minimized energy consumption, conserved resources, avoided adverse effects to the environment, provided occupant comfort, and reduced total cost of ownership by using a whole building, life-cycle approach.
One of the facility’s most notable features—invisible to daily shoppers—is the photovoltaic (PV) system on the rooftop of the retail center. The same conditions that can make Twentynine Palms such a brutal place to live and work also make it the perfect place to harvest the sun’s energy. Converted solar energy is generating 12.5 percent of the facility’s energy requirements. The estimated time to achieve return on investment is about five years.
An innovative type of PV system was selected, which adheres to and lays flat against the roof membrane. There are numerous benefits to this type of PV. For one, this system can achieve up to 20 percent more energy production per installed W, as compared to conventional arrays. Additionally, since the PV membrane adheres directly to roofing materials, there is no racking system. That means reduced material, labor and maintenance costs. Penetrations in the roof deck are not necessary, which significantly minimizes roof leak risk as well.
Exterior View of the Marine Corps Exchange retail store at Marine Corps Air Ground Command Center Twentynine Palms, Calif.
With wind ratings in excess of 185-mph, this system is resistant to wind uplift because of its direct adherence to the roof membrane. The Twentynine Palms area is prone to high wind, requiring a wind load design of 90 MPH. This system is highly durable, impact resistant and suitable for the blast resistant requirements of the military. It also retains more solar power at high temperatures than other PV products. This tolerance is significant for Twentynine Palms, where temperatures can push 120 degrees during the summer.
Base patrons want to be warm in the winter and cool in the summer. Most really are not aware of what is going on behind the scenes. A solar panel kiosk was installed in the store to further educate shoppers. The kiosk contains an interactive touch screen that allows shoppers to see how much energy the solar panels are generating and how much solar power is actually powering the building at a given time. The kiosk translates the savings into everyday terminology like how many trees were preserved or how many gallons of gas were saved.
Maintaining a pleasant shopping environment while meeting government sustainability goals has proven a success at the Twentynine Palms Exchange. Haskell, the facility’s integrated design-builder, conducted modeling of the proposed and baseline buildings as required by ASHRAE Standard 90.1-2004 Appendix G. The model resulted in a substantial savings of the proposed building over the baseline model. Energy savings were the result of utilizing sophisticated, high-performance equipment, control strategies and building materials. The outdoor air economizer, PV array, heat wheel, high-efficiency air handlers and variable primary pumping schemes had the greatest impact on the energy efficiency of the design. Systems were also selected based on their ability to minimize direct impact on ozone depletion and global warming.
Sustainability continues on the outside of this visually appealing facility. The Marine Corps’ colors and design standards convey the pride of the Marines and draw visitors into a unique one-stop shopping experience. The shell is composed of site-cast concrete panels, which meet anti-terrorism/force protection requirements and provide an energy-efficient, low-maintenance shell. The exterior concrete surfaces were coated with a highly reflective coating system, resulting in lower exterior wall temperatures.
The building exterior was complemented by a functional landscape design that addresses long-term sustainability. Recycled wastewater from the base’s wastewater system will be used for irrigation. The strategy of identifying drought tolerant native plant materials combined with the design of a highly efficient irrigation system worked to reduce the total water applied for irrigation by 62 percent from a calculated baseline case. Naturalized granite and river rock ground covers rounded out the highly aesthetic design.
Additionally, the burden on municipal water supply and wastewater systems was further reduced by maximizing water efficiency inside the building. Water saving urinals and automatic sensor type lavatory faucets with aerators were installed. When added to the reduced flush water closets, the net water savings is 42 percent.
The parking lot at Twentynine Palms features “Green Asphalt” and sustainable landscaping. Green “warm mix asphalt” reduces energy consumption during manufacture and application, lowers emissions, eliminates visible smoke, utilizes a higher percentage of recycle mix and provides longer pavement life. The parking area is also scattered with islands containing sustainable landscape design features.
Another innovative approach to sustainability on the new MCX involved using “Green Asphalt.” This type of asphalt was utilized for its economic, environmental and sustainable qualities. The benefits of using a warm mix asphalt include reduced energy consumption during manufacture and application, lowered emissions (no smell); elimination of visible smoke; a higher percentage of recycle mix; and longer pavement life. Traditionally, warm mix production relied on expensive chemical additives, but the “Green Asphalt” system works by adding small amounts of water to create microscopic bubbles, leading to a superior, warm mix asphalt.
Some 92 percent of construction waste was diverted from reaching landfills. Procedures to accomplish this notable task were distributed to the architects, engineers, construction management personnel and subcontractors. It was a team effort, according to the LEED accredited project manager, Michael McCarthy.
Meetings were held to reinforce everyone’s responsibilities. A total of 57,000-ft² of existing 4-in asphalt was ground up and incorporated onsite as fill. Additionally, five separate dumpsters were clearly marked to sort waste, which was then diverted to a nearby recycling facility. Now that the store is open for business, it has continued with a rigorous recycling program to address all the waste associated with a facility of this size.
A Welcomed Facility
What makes this facility special? Is it the way products are displayed; the smiles of military families; or maybe the convenience? While all these results are of utmost importance to MCCS and welcomed by Marines and their families, the most significant aspect of the new MCX is its sustainable design and construction. The facility successfully embraces the day-to-day needs of the Marine while minimizing impact on the surrounding environment and to the planet at large.
The new MCX is a welcome addition to a base that was singled out by the Department of Energy as having strong potential for large-scale solar development. It is interesting to note that the MCX profits are recycled as well. These dollars are reinvested in funding for other community programs provided by MCCS. The efficiency of this facility is a small step in the right direction and a welcome addition to the great sustainability strides already taking place within MCCS and at Twentynine Palms.