A big-box Walmart Supercenter in Covina, Calif., will be the site of a pilot project to assess the effectiveness of emerging energy efficiency technologies to significantly cut energy use by 20 percent in buildings throughout the state.
Led by the CSE, the project is funded by a $2.9 million grant from the California Energy Commission. It is part of efforts to reduce energy use in large retail and commercial buildings and develop ways to help create a more stable electrical grid and meet the state’s carbon emission reduction goals.
The project will test the capabilities of five innovative energy efficiency technologies that are new or currently not commercially available in an existing big-box store (retail plus grocery) located within a typical inland California climate zone. If results are positive, the technologies could move quickly into the commercial market and be deployed in similar retail buildings across the state to cut energy use and curb greenhouse gas emissions.
State-mandated energy reductions
California Senate Bill 350 has set ambitious goals to lower electricity and gas use in buildings overall, equivalent to a 20 percent reduction in projected building energy use by 2030. This will require every new and existing building to decrease its future energy consumption, according to Gene Kogan, a CSE engineer and senior project manager.
“It’s not as difficult to accommodate deep energy savings during new construction as it is for existing facilities that require the energy efficiency measures to be retrofitted,” Kogan said. “This project gives us the ability to rigorously evaluate precommercial energy technologies in a real-world situation without the building owner having to risk investment in technologies offering unproven savings potential.”
Reduced energy use also means lower energy costs. A report released by Environment America and the Frontier Group found that big-box stores spend on average $190,000 on electricity bills per year.
Walmart as energy leader
Overall, Walmart has set a goal to power 50 percent of its operations in 11,600 buildings worldwide with renewable energy by 2025 and is focusing on energy efficiency. Since 2010, the company has reduced its energy use per square foot by 12 percent.
The technologies to be installed at the Covina Walmart include a novel building energy controller built by SmartGreen, a software company specializing in optimization of refrigeration systems and heating, ventilation and air conditioning (HVAC) equipment. Tests of their control platform have shown it can reduce refrigeration electricity consumption by 20-40 percent with improved equipment performance and reduced downtime.
The store’s fluorescent lighting will be replaced with energy-efficient LED fixtures operated by an advanced control system and a direct-current (DC) “microgrid” designed by Robert Bosch LLC. By using DC power instead of standard alternating current, or AC power, the lighting can use the DC electric power generated by the store’s rooftop solar array without having to convert it to AC and consequently realize a considerable cost savings. The DC system also ensures emergency lighting because its operation does not depend on the electrical grid.
Existing HVAC and refrigeration systems will be upgraded using a combination of products. Motors in rooftop air supply fans and in-store refrigeration equipment will be replaced with ultra-high-efficiency, variable-speed motors manufactured by Software Motor Company. Accessory cooling systems built by Integrated Comfort Incorporated that pretreat incoming outdoor air will be installed on HVAC units. A water management system made by SAYA will be monitoring the water use and consumption of evaporative cooling components.
Integrated energy approach
“In a retail environment, energy efficiency retrofit measures are generally installed individually and not developed as a package of upgrades,” Kogan said. “Our integrated approach may cause companies to rethink the economics of combining more expensive measures and energy monitoring if upgrades provide a quick return on investment and improve system reliability.”
In addition to the Center for Sustainable Energy and the product manufacturers, other project partners include the National Renewable Energy Laboratory, TRC Energy Services, P2S Engineering and DAVEnergy Solutions. The energy efficiency in big-box retail project is featured on the California Energy Commission’s online Innovation Showcase.