In 2014, Lockheed Martin completed an energy savings performance contract (ESPC) at the U.S. Embassy in Nicaragua that will achieve a 54 percent energy reduction across nine buildings. This project was unique as it achieved deep energy savings in relatively new buildings despite the unique communication issues inherent in international embassies (management rotates every two years) and a lack of local utility incentives for renewables. An additional project phase currently in development will build toward net-zero energy use.
Key Energy Conservation Measures (ECMs):
- 2,238 LED replacements
- Chiller-plant optimization with staged loading
- Variable-refrigerant, multistage, direct-expansion cooling systems
- Building-automation-system retro-commissioning and sequence optimization
- High-efficiency transformer upgrades
- 956 kW high-efficiency solar PV
Making Solar Work
Despite Nicaragua’s abundant year-round sunshine and high electricity rates, a lack of local utility incentives impeded the implementation of solar PV on this project. Without an available utility net-metering program or other local financial incentives, solar PV would have a high capital cost and any excess generation (e.g., that planned for phase 2) would be lost. Additionally, embassy staff members were concerned that a large, ground-mounted solar installation would negatively affect the aesthetics of their work environment.
Lockheed Martin and the Department of State (DOS) Bureau of Overseas Buildings Operations (OBO) worked hand-in-hand with renewable-energy specialists from Lawrence Berkeley National Laboratory (LBNL) and the Department of Energy (DOE) to build confidence around the solar installation by comprehensively modeling the financial impacts of various simulations, including a potential battery-storage system to capture excess generation (now being considered for phase 2). LBNL and DOE specialists provided the independent third-party expertise necessary to build project buy-in, and the Department of State now utilizes third-party specialists for prospective overseas ESPCs with renewable installations. Tenant concerns were addressed by specifying a carport canopy installation on existing parking lots, which reduced the ground-mount system size by nearly half and provided the added benefit of vehicle protection to employees. The resulting 956 kW PV installation, the State Department’s largest overseas system, is projected to offset 37% of the retrofitted site’s energy consumption. Studies for a second ESPC include additional PV capacity and battery storage.
*From PA kickoff to final acceptance
**Savings are recouped by energy service company through contract term
Potential in New Buildings
Despite an average building age of seven years, project engineers were able to find significant savings through integrative design and by installing higher efficiency equipment. Savings hinged on a comprehensive LED-lighting retrofit and HVAC unit replacements, saving over 460 MWh and 390 MWh per year, respectively. Lighting savings were compounded by LEDs’ superior color rendering, which improve conditions for visual security even under reduced lighting levels. The lighting retrofit’s significant effect on building-cooling loads also allowed for replacement HVAC equipment to be downsized, creating up-front capital savings.
Project engineers noticed early in the development process that the existing central chiller system was oversized for periods of low occupancy, and that frequent system cycling during off-hour loads had forced facility managers to lower cooling set points during nights and weekends to false-load the system. Because existing chillers were in good condition, the project team opted to install an additional lower-capacity unit to meet off-hour loads. This reduced equipment wear and increased runtime efficiency in buildings connected to the central HVAC system. In other buildings, split-system AC units were replaced with variable-refrigerant-volume direct-expansion systems.
The Power of Effective Communication and a Motivated Team
Because embassy management turns over every two years, maintaining a consistent knowledge base and ensuring continuity of communication and project management were particularly challenging. With a diverse set of stakeholders based in both the U.S. and abroad, keeping an active line of communication open was central to achieving each entity’s goals.
Both Lockheed Martin and the State Department attributed the project’s success to the OBO project manager, who addressed communication concerns by developing a memorandum of agreement (MOA) that memorialized approvals and allowed knowledge about the project to live beyond staff turnover. The document, which summarized the intent and details of the ESPC and described project roles, was required reading for all incoming Managua staff and supplemented centralized project management out of OBO’s D.C. office. The Department recognized the MOA as an essential tool in the communication and implementation of ESPC projects overseas.
The momentum for this project stemmed from the 2011 Presidential Performance Contracting Challenge and the State Department’s Greening Diplomacy Initiative, whose view is that embassy sustainability projects provide an excellent opportunity to improve the United States’ image abroad and enhance the security of overseas operations. This diverse support set the project’s tone and set an expectation for exemplary savings, leading agency representatives to tell Lockheed to “leave no stone unturned” during the PA phase rather than strictly focus on a few ECMs. Team members credit this fully optimized approach with forging a cutting-edge efficiency project now used as a case study throughout Nicaragua.
“Through [these projects] we show that we stand with the many Nicaraguans from all walks of life who are working to protect the environment.”
-Phyllis Powers, U.S. Ambassador to Nicaragua
Image courtesy of Lockheed Martin.