U.S. Department of Energy - Energy Efficiency and Renewable Energy

Building Technologies Office

SAVING ENERGY

Photo of the exterior front of the Leavenworth, Kansas, Walmart featuring a tall light in the parking lot.

WALMART

Save Money and Energy With LED Lighting:

Lighting Uses the Most Energy in U.S. Commercial Buildings:

Graph shows carbon dioxide emissions relative to primary energy used in lighting. Carbon dioxide emissions are denoted in an arch shape at 18%, while primary energy use is denoted at 17% and is shown underneath of the carbon dioxide emissions statistic.

Lighting accounts for 17% of primary energy used in commercial buildings and almost 18% of their carbon dioxide emissions, according to the U.S. Department of Energy's (DOE) Buildings Energy Data Book.

Specification Highlights:

The LED Site Lighting Performance Specification provides requirements for lighting the site as well as the luminaires. Here are a few key details of the specification:

  • Both power density and illuminance requirements are by lighting zone (LZ); different amounts of light (illuminance) are needed for different parts of the parking lot, and different environments need more or less light (and thus use power differently).

  • Luminaires should follow the backlight, uplight, and glare (BUG) rating requirements in IESNA TM-15.

  • Luminaires should carry a five-year warranty covering the luminaire, finish, and power supply.

  • Testing requirements are identified.

Will this information help you save energy?


LEDs and Specification for Parking Lots Lighten Energy Load

Walmart Commits to Energy Efficiency with the Building Technologies Office

An often-overlooked yet integral part of our communities' landscapes, parking lots influence how we live, work, and play. Parking lots also require substantial energy and money to operate. Business owners have long recognized the potential of light-emitting diode (LED) technology in parking lot lighting—to save energy, reduce maintenance costs, and improve environmental sustainability.

LEDs have been shown to save energy in limited applications, but are they ready for wide-scale adoption?

Walmart responds with a resounding "yes." The company's experience with the U.S. Department of Energy's (DOE) Building Technologies Office (BTO) in implementing LEDs paves the way for other parking lots, exhibiting how efficient lighting technology and design positively impacts business goals and community needs. DOE estimates that using the LED site lighting specification will reduce parking lot energy use over 50% compared to typical code. Sites should also see reduced maintenance costs due to the long expected life of the LED system and deferred maintenance.

Developing a Comprehensive, Cost-Effective Solution

To validate the energy and cost-savings potential of LED lighting for retail parking lots, BTO collaborated with industry members of the Retailer Energy Alliance (REA). One of BTO's Commercial Building Energy Alliances (CBEAs), REA has active retail members of all sizes from across the United States including Target, Whole Foods, and McDonalds.

REA representatives worked with researchers at Pacific Northwest National Laboratory to develop a set of criteria retailers could follow to implement LED parking lot lighting and realize energy savings and reliability. The LED Site Lighting Specification (Specification) provides information about both luminaire, or light fixture, performance and how the site should be lighted. For instance, the Specification outlines how lighting needs vary across the different parts of the parking lot. The Specification optimizes the performance of sites, satisfying more than pure lighting needs. Business concerns such as site aesthetics, branding, and customer safety also come into play.

Additionally, the Specification recognizes the potential risks businesses face in adopting new technologies, including reliability and maintenance costs. To address these, the Specification requires that manufacturers guarantee product performance with a five-year minimum warranty for LED luminaires.

World's Biggest Retailer Sees the Light

REA member Walmart actively participated in building and testing the specification. The world's largest retailer, Walmart operates more than 4,300 facilities in the United States—including Walmart supercenters, discount stores, Neighborhood Markets, and Sam's Club warehouses—and encompasses over 699-million-square-feet of floor space.

Walmart leverages its size and distribution network to drive energy efficiency throughout its operations and into its supply chain, making it a major force for sustainability and energy savings in the retail sector. The company has been opting for LED systems over high-intensity discharge (HID) lighting in non-domestic locales with significantly higher energy costs than in the United States.

"Because electricity is the number two operating expense in almost every one of our [Walmart] stores around the world, we need to focus on efficiency and reducing energy use, particularly from lighting. This is a great example of putting powerful research into action for impactful results."

Charles Zimmerman, Vice President of International Design and Construction, Walmart

Until the Specification's arrival, Walmart had proceeded with caution in its U.S. operations because of questions about the long-term cost and reliability of LEDs in the domestic market. However, the Specification's emphasis on LED reliability and effective site design, combined with dropping prices for LED luminaires, changed the game for Walmart's leadership: It was the right time to invest in a demonstration project and test the holistic approach of the Specification.

Demonstration Project Saves Energy And Money; Becomes Model For Future Facilities Planning

In 2009, the new Walmart Supercenter in Leavenworth, Kansas, opened and became the first site to implement the Specification. Via BTO's Solid-State Lighting Technology Demonstration GATEWAY Program, Walmart compared the cost of a conventional HID system to a new LED system for the Kansas site. While the initial cost of the LED system was higher, the energy and maintenance costs over the expected 10-year lifecycle is much lower, making the LED system more cost effective over time. Walmart anticipates cutting maintenance costs by more than 30%.

In terms of energy savings, Walmart's senior mechanical, electrical, and plumbing (MEP) systems engineer, Ralph Williams, states "Walmart expects LED parking lot lights to reduce energy needs in its parking lots by more than 50%, delivering average energy savings of over 125,000 kWh a year per site. The energy savings is the equivalent of the energy consumed by 11 American households annually."

Both BTO and Walmart enthusiastically agree the project proved the Specification works in the real world. The positive financial impact of deploying the Specification at the Leavenworth, Kansas, site impressed Walmart management, commented Williams. As of January 2011, the organization plans to incorporate LED parking lot lights into all U.S. approved new construction sites in compliance with the specification. Since January, Walmart has planned for over 225 new sites to include LED parking lot lighting.

Walmart's adoption of LED parking lot lighting generates industry-wide savings. Due to the sheer scale of the global company, Walmart's commitment to LEDs will drive down the cost of the technology— good news for all commercial property operators and owners who want to save energy and money.

How You Can Get Started

Building owners and operators, product manufacturers, city planners, architects, and engineers can use the LED Site Lighting Performance Specification as a tool to make and support the business case for investing in up-to-date, energy efficient parking lot lighting systems. As Walmart's experience demonstrates, applying the Specification saves money over the lifetime of the LED system.

Contact BTO to find the resources best suited for your organization and efforts. Working together, we can meet energy reduction goals and strengthen the nation's energy future.

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