Instituting a 10-year retrofit program for the country’s commercial spaces could save $41.1 billion in energy expenses every year, according to a new report by Pike Research.

According to the report, as of 2010, more than 80 percent of commercial buildings in the U.S. were more than 10 years old. Pike estimated that a 10-year retrofit program would cost a total of $22.5 billion over its 10-year span.

Commercial buildings cover a total of 79 billion square feet and are one of the leading sources of energy consumption and carbon emissions, according to the report.

However, despite these promising numbers, Pike Research’s analysis found that the actual market for energy efficiency retrofits is only a small fraction of the potential.

The best-funded opportunities for retrofits today are major upgrades in institutional buildings, especially in federal buildings. This market, already strong because of federal policy mandates and creditworthiness, received a boost from the American Recovery and Reinvestment Act (ARRA).

However, federal non-industrial buildings comprise less than 3 percent of existing commercial space, and the largest untapped potential is for energy retrofits in private commercial buildings.

Pike Research anticipates that several key market barriers will be successfully overcome during the next few years, and the firm expects that the private retrofit sector will experience strong growth through 2014 and beyond.

Several drivers are expanding the potential market for energy efficiency retrofits in commercial buildings, which can provide energy savings from 10 percent to more than 50 percent.

In addition to cost savings, energy retrofits are attractive for purposes of greenhouse gas (GHG) reductions, energy independence, green branding, property valuation, and productivity. However, the actual market is small compared to its potential, due to an assortment of barriers within various industry segments.

Kohl’s said it recently reduced its energy costs by $50 million by instituting energy efficiency measures in its stores. San Jose State, meanwhile, said it is saving $300,000 a year after retrofitting its lighting systems to more efficient fixtures.