Building Electrification Considerations for Big Box Retail Stores | Henderson Engineers

Building Electrification Considerations for Big Box Retail Stores

Corporations around the world are pledging to become carbon neutral by 2050 or sooner. One of the key components of achieving this goal is building electrification, which is the process of converting buildings from fossil fuels to electricity.

Building electrification presents a tangible strategy within our industry to reduce and eliminate long-term operational CO2 emissions. More specifically, we can effectively eliminate 28% of annual global CO2 emissions if we operate all our buildings on electricity and if that electricity transitions to carbon-free and renewable energy over the next 13 to 18 years.

Big box retail stores are a major target for building electrification. These stores typically have a large electrical load, and they are often located in areas with access to renewable energy sources.
However, there are a variety of considerations that need to be addressed when electrifying a big box retail store.

Aging Infrastructure

The age of the building’s electrical infrastructure is a key factor. In many big box retail stores, the electrical infrastructure may be nearing the end of its lifespan and may not be able to manage the additional load of electric equipment. The industry standards for useful life of electrical equipment are as follows:

  • Transformers: 25-30 years
  • Circuit Breakers: 15-20 years
  • Switchboards: 30-40 years
  • Panelboards: 20-30 years
  • Conductors: 30-40 years

Several conditions can affect the life expectancy of this equipment. The major concerns are maintenance, upkeep of the equipment, and environmental conditions. Electrical equipment creates heat, so it likes to operate in a cooler environment. Cleanliness is another concern for life expectancy. Dirt or dust built up on the equipment will not only degrade the components but also add a layer of insulation to remove cooling capability.

The electrical service is the main connection between the building and the utility grid. It may need to be upgraded to provide enough capacity for the new electric loads. Additionally, the cost of electrifying a big box retail store can be significant. However, there are incentives available to help offset the cost, such as tax credits and rebates. Additional considerations for electrification of big box retail stores include:

  • Service Disconnect Quantity: In 2020, NEC Article 230.71 was revised to no longer allow multiple service disconnect switches in the same cabinet. Many installations prior to this revision took advantage of this rule by providing six smaller service disconnects in the same board in lieu of one larger service disconnect switch. Any changes that need to be made to the existing electrical services that utilize the previous six switch rule could be required to upgrade the entire service entrance to comply with the new standard.
  • Obsolete Equipment: As equipment ages, the manufacturer will no longer support it thus making it obsolete and eliminating the availability of parts for replacement other than the aftermarket.
  • Molded Case Circuit Breakers: The most common component of the electrical distribution system is a molded case circuit breaker. The 2020 NEC 240.88.A.1 or 2023 NEC 240.2 code prohibits the use of refurbished molded case circuit breakers. Once the manufacturer stops production of a specific model, finding a new replacement circuit breaker is difficult.
  • Hot Spots: Hot spots are locations in the electrical distribution system that are typically caused by loose connections or overloaded devices. The concern is that those spots could cause a fault or degrade the integrity (and lifespan) of the component.
  • Increased Fault Current: Over time, the fault current available at the electrical service from the utility service provider can increase beyond what was originally expected or designed into the electrical distribution. If the AFC (Available Fault Current) exceeds the electrical equipment rating to withstand the fault, it could cause a catastrophic event under the right conditions.
  • Arc Flash Concerns: Arc Flash is the part of an arc fault that emits light and heat and can cause substantial damage, especially to a person without the proper PPE (Personal Protective Equipment) to ensure they are safe. This has become an increased concern with code revisions over the last 10 years that place the burden of ensuring a safe work environment on the building owner.
  • Flexibility of Existing Infrastructure: The original electrical service equipment installed at many locations was right sized to minimize the cost and space requirements. This usually does not allow for space to connect the new electrically powered equipment.
  • Lack of Maintenance Program: Many retailers with stores spread across the USA and world, some in remote locations, did not have the convenience of an available national electrical contractor to provide maintenance at all their locations. This and the drive to reduce operating costs meant many did not perform yearly maintenance to their electrical distribution systems; opting instead to wait until an issue arises in the electrical system. Deferred maintenance usually results in equipment that has a shorter lifespan and may not operate properly when shut down to add new loads to the system; adding cost to replace components that were not anticipated.
  • Renewable Energy: The availability of renewable energy can also play a role in the electrification of big box stores. If the building is in an area with access to renewable energy, such as solar or wind power, this can help to reduce the overall cost of electrification.

How to Address Concerns with Aging Infrastructure

While there are numerous concerns to consider and anticipate when dealing with aging infrastructure, there are solutions:

  • Replacement of Obsolete Equipment: Replacing obsolete equipment will ensure that the equipment will operate as intended and, if an issue occurs, replacement parts can be readily found to bring the electrical service back online.
  • Fault Current Study: A fault current study will reveal current deficiencies in the electrical system and allow adjustments to be made to handle fault current issues.
  • Arc Flash Study: NFPA 70E (electrical safety code) requires re-certification of arc flash labels every five years. This is a different study than a fault current study but has similar characteristics as it uses the fault current values and evaluates the length of an event to release energy. This energy release is potentially extremely dangerous.
  • Thermography Studies: Thermography studies expose “hot points” in electrical equipment that have loose components or overheated devices.
  • Preparation for Future Electrification: Conversion of existing gas equipment will require additional electrical capacity.
  • Implementation of Maintenance Program: Maintenance programs are important for ensuring electrical components operate correctly when an event does occur.
  • Add Capacity for New Electrified Loads: Added connection capacity for renewable energy and the addition of EV (Electrical Vehicle) charging will require additional capacity that is not currently accounted for in the electrical service.

Building Electrification Considerations

Despite the challenges, building electrification is a viable option for big box retail stores. By electrifying their operations, these stores can reduce their reliance on fossil fuels and help to fight climate change.
Some specific considerations for electrifying the HVAC, water heating, and kitchen equipment in big box retail stores include:

  • Existing gas heating equipment could be replaced by either purely resistive electric heat units or heat pump units depending on geographical region. In either case, there could be a significant electrical load added to the building if all units are replaced. In many cases, this will be the leading factor in triggering an electrical service upgrade for the building. In addition to a potential service upgrade, the existing interior electrical infrastructure must be expanded to accommodate the larger branch loads.
  • Water heating electrification will typically have a small impact on the overall infrastructure as many smaller water heaters (<= 50 gal) are already electric units. Larger gas water heaters transitioning to electric water heaters would require overcurrent protection and branch circuitry to be replaced with a larger size.
  • Larger kitchen equipment such as ovens and fryers transitioning from gas to electric units will require overcurrent protection and branch circuitry to be replaced with a larger size.
  • Supplemental Space Heating at doors and other locations that require additional heat that are currently served by gas will need to be replaced by electric heating.

Despite the challenges, building electrification can be a cost-effective way to reduce emissions and improve the energy efficiency of these facilities. By taking the necessary steps to address the challenges, these stores can make a significant contribution to the fight against climate change.

Henderson Knows Retail

Our history is rooted in retail and it remains a focus today with multiple clients on the Top 100 retailers list. Our retail sector experts work on all sizes and types of projects from programmatic, nationwide retail and restaurant chains to specialty retail stores, luxury brand flagships, and new car showrooms. Through sustainable engineering solutions, we help our clients lessen their environmental impact. We understand what motivates and moves consumers inside a store and how to incorporate technology to create unique, omnichannel brand experiences that result in customer sales.

Written By
HARVEY WARD

Senior Electrical Engineer

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