Solar panel makers trying to get around tariffs President Donald Trump has imposed on imported equipment are running out of time.

Companies have through Friday to seek exemptions to the 30 percent duties that went into effect last month. Thirteen had as of Friday morning, according to the U.S. International Trade Commission’s website. SunPower Corp., which makes most of its panels in Asia and Mexico, has argued that its higher-efficiency technology gets a premium and doesn’t harm U.S. factories. Enphase Energy Inc. says it should be excluded because its electrical equipment is made in California before getting shipped to panel makers to attach to U.S. imports.

“SunPower gets a premium for a differentiated product and if it’s just a couple requests that aren’t lost in a sea of comments, they have a good shot,” Shane Skelton, managing director at Veda Partners LLC, said in an interview. A decision on exemptions could come as early as late May after a 30-day comment period, he said