Energy Upgrades at The Exchange
An integrated approach to energy management is producing significant savings at Exchange Express stores.
By Kurt E. Bohlman, CEM, LEED AP
With improvements to the efficiency of the small BEAR shelters as well as the ECUs used to heat and cool them, two tents can be temperature controlled with one ECU.
In 2010, the Army & Air Force Exchange Service (The Exchange) decided to replace its traditional energy audit program with an integrated energy management process that analyzed opportunities from a holistic, whole-building perspective.
This integrated energy management approach was piloted in 2012 at an Express store at Fort Hood, Texas, and proved immediately successful, with energy measurements indicating savings of 30 percent to 50 percent per month. As a result, the agency is rolling out similar energy upgrades to approximately 270 stores.
The cornerstone of The Exchange’s energy management program previously had been the energy audit program, an overly long process that comprised five specific objectives:
- Assess the energy efficiency of metered facilities.
- Recommend energy conservation measures (ECMs) with less than 5-year simple payback and return-on-investment greater than 7 percent.
- Identify maintenance efficiency opportunities.
- Review past utility billing data and analyzing consumption history,
- Provide a formal audit report to facility stakeholders.
The already cumbersome process was exacerbated by the vast number of Exchange facilities and geographic locations, a variety of building types and complicated utility bill surveys. Audit reports in some cases took 18 months, making them obsolete before reaching the facility manager. The use of multiple vendors to conduct the audits also was a challenge, with multiple or inconsistent results. The most discouraging aspect was the lack of ECM implementation. If measures were done at all, it was individual ECMs with short paybacks.
While the traditional audit program could produce some positive results (such as identifying more energy-efficient equipment for new construction standards and improving operating procedures at existing buildings) it was clear that achieving a portfolio-wide 30 percent energy reduction by 2015, as directed in Executive Order 13423, would be doubtful at best.
BUILDING A NEW IDEA
In 2010, the Energy Management Division was challenged to propose “Big Energy Ideas.” One suggestion was to streamline the entire energy management process. Another idea was to conduct a whole-building pilot project utilizing building controls and equipment upgrades. Ultimately, combining the two ideas meant utilizing all aspects of the integrated process. The goals were to:
- develop projects with high return;
- streamline the energy audit process;
- bundle ECMs;
- seek alternate funding sources (such as utility rebates and grants);
- implement project(s);
- use a “turn-key” contractor to execute project(s) from cradle-to-grave; and
- validate project results.
Liners have been added to the inside of the BEAR tents to provide insulation. This helps reduce the workload for the ECUs and keeps the temperature regulated inside the tent.
The prevailing idea was to analyze opportunities from a whole-building perspective. It would be important to complete energy projects in a turn-key manner—to utilize one contractor to conduct audits, procure materials, manage rebates, and install and commission equipment.
To identify an engineering firm capable of performing such projects, a multiplesource solicitation was conducted, with a value added procurement proving best suited for this work.
An indefinite delivery/indefinite quantity (IDIQ) contract was issued for a two- year period with a one-year option period. The contract stipulated that a pilot project with a 60- to 90-day test period be conducted at the Warrior Way Express at Fort Hood. If the pilot proved successful, the contract would cover a full rollout to up to 300 Express facilities, with an estimated project cost of $20 million, contingent on funding.
PILOT RESULTS & ROLLOUT STRATEGY
Energy retrofits and controls were installed on interior and exterior lights and refrigeration equipment. A new energy management control system monitors building, HVAC and refrigeration energy usage.
Measured electric savings during the test period were 40 percent to 50 percent per month. Eight months after the installation, metered data still indicated a remarkable energy savings of 49 percent. The Exchange has approved the project rollout to nearly 270 stores. The current goal is to complete all upgrades by the end of 2013, funding dependent. To date, roughly 43 building upgrades are complete at 14 U.S. Army and Air Force installations.
Although a rollout is approved by The Exchange for the entire store portfolio, individual projects are created for each building. The energy audit dictates what measures are proposed and eventually approved for each building project. Using pre-determined financial criteria, the project manager chooses bundled measures for each building. The rationale is to approve projects that are both financially attractive (five- to six-year simple payback) and meet company policy (internal rate of return greater than 7 percent). A controls package is added only if the total simple payback (ECMs plus controls) is less than six years. The project manager will not approve projects that impact the store’s bottom-line, where monthly depreciation from project cost is greater than monthly energy savings.
To reduce transportation and expense costs, energy audit and equipment install trips are grouped geographically. Trips are prioritized by cost savings potential. The scope of the pilot project and rollout sites includes all interior equipment and exterior lighting. The energy auditor provides all ECM opportunities, within reason, to the project manager. The only recommendations not to be considered are motion sensors for retail and freezer lights, and retrofitting equipment in need of repair or replacement. The most common ECMs identified in Express stores include:
- Electronically commutated motors and controls on refrigeration evaporator fans provide increased efficiency and speed reduction—70 percent to 80 percent savings.
- LED bars and occupancy sensors on reach-in cooler doors reduce lighting energy and operating hours—90 percent to 95 percent savings.
- High-efficiency reflector retrofit kits, ballasts and reduced wattage lamps on interior fluorescent light fixtures provide superior light levels with fewer lamps per fixture—39 percent savings.
- Anti-sweat heater controls monitor moisture levels on reach-in cooler doors reducing unnecessary door heating and cooling load—80 percent to 90 percent savings.
- Occupancy sensors on stock room, office, restroom, break room and walk-in cooler lights permit select lights to turn off when area is vacant—71 percent savings.
- Induction parking lot pole and wall pack light fixtures provide similar light level with less energy and a longer life (100,000-hours)—74 percent savings.
- Energy management control system allows for HVAC and refrigeration tracking; verification of savings through real-time utility metering; temperature setback and control; and safe control and scheduling of all interior and exterior lights.
There are several advantages and a few lessons learned in applying the integrated energy management strategy. Under the new process, “comprehensive” energy efficiency projects, with greater energy reduction benefit, are identified and installed. One turn-key contractor performs all projects from cradle-to-grave. This allows auditing of more buildings in a shorter period of time and ensures uniformity and simplifies warranty management. With a single IDIQ contract for all Express stores nationwide, new contracts are not created for individual facilities.
A drawback to the streamlined approach, however, is the elimination of the billing review from the audit process. Errors now may slip through the cracks, leading to inaccurate billing and consumption reporting. Another disadvantage is that the current IDIQ contract is not applicable to all building types in the portfolio.
By elevating its energy management approach, The Exchange will incorporate a building portfolio strategy. Its future initiatives will further this effort. The agency also is partnering with the Rocky Mountain Institute to improve energy efficiency across main stores and food courts. The team is analyzing a portfolio approach that will identify energy efficiency opportunities that can be applied to multiple facilities.
This expanded approach will further help The Exchange comply with EO 13423 and stay on a path to reduce energy use intensity 30 percent by 2015.