Five years after installing solar panels on the roof of its office building, organic produce marketer CF Fresh has seen its energy use fall by 12%.

In 2007, Sedro-Woolley, Wash.-based CF Fresh installed 130 Sanyo HIP 195 solar panels and four SunnyBoy 6000 inverters, according to a company news release.

Before CF Fresh installed the panels, its electrical usage had been rising by 7.5% per year. The panels have not only slowed that growth, they’ve reversed it. Total usage in 2012 was 12% lower than in 2006.

“This project is truly sustainable both financially and environmentally,” Steve Mackey, the company’s executive vice president, chief financial officer and part owner, said in the release. “While the upfront investment was considerable, solar technology has advanced to the point where the life expectancy of the solar system far exceeds the expected cost recovery period on the project.”

The solar panels generate 20,000 kilowatt hours annually, and their percentage of total energy used by CF Fresh has risen. In 2008 they produced 37% of the total electricity used at the office. By 2012, the percentage had risen to more than 43%.

When CF Fresh installed the solar panels, it also made other energy-efficient upgrades, Mackey said.

“We took the time to evaluate all potential energy savings,” he said. “The project included upgrading to more efficient light fixtures, upgrading HVAC systems, replacing incandescent bulbs with compact florescent, replacing CRT computer monitors with LCD flat screens and installing windows to take advantage of natural light, among other things.”