At the end of February 2014, the United States Energy Department announced new efficiency standards for commercial refrigeration equipment. These standards will make the average commercial refrigeration unit about 30% more efficient, helping cut carbon pollution by about 142 million metric tons over the next 30 years.
In the short term, however, an intriguing and relatively easy opportunity to reduce carbon emissions from commercial refrigeration has been overlooked—the US wastes an enormous amount of energy keeping frozen food far colder than it needs to be.
The standards, established more than half a century ago to prevent food-borne illness and ensure food quality, require that both commercial and home refrigerators be kept at 41°F or lower, while the recommended temperature for freezers is 0°F or lower. While the refrigeration standard still makes sense—food-borne bacteria multiply rapidly above 41°F, and contribute to an estimated 48 million illnesses and 3,000 deaths in the US annually—the freezer standard does not.
Moving from 0°F to 5°F offers huge electricity savings and carbon reduction, with no impact on food safety. For every degree the standard is raised, there is roughly a 3% reduction in electricity use.
Electricity production generates the largest share of greenhouse gas emissions, at about 32% of the US totals; refrigeration alone accounts for nearly 6% of total electricity consumption. Modifying temperature set points in freezers could shave 10% of total refrigeration electricity use, eliminating about 13 million metric tons of greenhouse gas equivalents annually and saving electricity customers over $2.2 billion per year.
So, why has this change not been made? It may be, simply, that no one has considered the issue for a long time. The origins of recommended temperature set points for frozen food go back to research conducted in the 1940s and 50s at the Western Research Laboratory in Albany, CA, when frozen food first began to be more widely available. This group of studies were called the Time-Temperature Tolerance Studies. While not a linear relationship, research showed that colder freezing temperatures had some bearing on food quality and shelf life. In other words, food kept at 0°F might be of high quality for 10 months, while at 5°F, it would be considered high quality for 8 months. With a desire to expand the market for frozen food products, it was key that consumers believed that frozen food could be of high quality. So, industry pushed for a colder temperature standard.
The first food handling code was developed back in 1961 by the Association of Food and Drug Officials of the United States (AFDOUS), a group of industry representatives and academics (many from the Western Research labs) that concluded that freezing to 0°F was necessary to ensure food quality and stability from manufacturing to transport to the final retail destination. Following the release of this code, many US states began to implement regulatory handling codes for frozen foods, all following the requirements recommended by AFDOUS. And today, public health officials who visit manufacturing and retail locations to monitor freezer temperatures are checking to make sure these 50-year-old standards are still being followed.
Today, the question is: Does a 0°F requirement for frozen food still make sense? In an environment with increasing electricity prices and better temperature management of frozen food it may not.
In 1961, 0°F helped protect the quality of food, due to the invariable changes in product temperature as product moved along an unsophisticated cold chain, from manufacturer to rail cars, to refrigerated trucks, and to the end retail destination. According to the American Frozen Food Institute (AFFI)—an industry association—food is far better managed today than it was in 1960.
“The frozen food industry has progressed to ‘just in time’ logistics,” says Donna Garren, AFFI Vice President of Regulatory and Technical Affairs, meaning that temperature management is smarter throughout the transportation process, and food does not stay in any one place warming for extended periods of time.
With smarter temperature management, a standard of 5°F is appropriate and the benefits are undeniable. For businesses such as grocery and convenience stores, where over 50% of their total electricity use is on refrigeration, such a change would offer significant savings—for larger grocery stores, upwards of $15,000 yearly per location.
For homeowners where refrigeration represents 8% of the total electricity bill, according to the Energy Information Administration (EIA), there would also be savings and no risk. As bacteria do not multiply in food that is frozen, a slightly warmer frozen food temperature standard offers no danger of food-borne illness.
The most important benefit could be for public utilities, where there would be drop in peak energy demand given refrigeration is run all day. Peak energy demand occurs generally during the hottest months of the year in states like California when air conditioning is used extensively. During these periods of time, generally late afternoons on summer days, any way of reducing peak demand offers savings for the utilities and reduced risk of brownouts on the electricity grid.
Making a change to the temperature standards within freezers is not a difficult policy issue to take on.
First, it is key to have industry on board.
“With increasing costs of electricity and the frozen food industry’s push for energy efficiency, this is an opportunity that is worth examining,” says Garren.
Second, there would need to be some examination of contemporary research being conducted on food quality and stability. Work being conducted by Professor Da-Wen Sun at the University of Dublin is the most up-to-date. Some research suggests there may need to be exclusions for frozen fish, which initially needs to be flash frozen at extremely cold temperatures, but afterward may be stored safely at 5°F. Assuming there are no concerns raised that would create risk for industry and consumers, US states would simply need to modify standards allowing for warmer freezer temperatures.
With the government looking for ideas to save energy and reduce greenhouse gasses, examining a change to the temperature standards in freezers is low-hanging fruit with no cost and great benefit. If accepted, this is also an idea that could be adopted globally, eliminating the need for about 82 mid-sized coal-fired power plants. With climate change continuing to emerge as a significant global threat, this is a small solution that has global implications.
