now a spanish company is working on ways to make ballooning greern.itor went to their factory. >> reporter: it's dawn in the hills near barcelona, and in the still morning air, a newly completed hot air balloon is inflated for the first time. the team inspects the rigging and the stitching on all of the seams. it's a standard check performed before new balloons are shipped to customers. the spanish company is the world's largest maker of hot air balloons, producing around 200 each year. the design, color scheme, and branding of each balloon is customized then stitched together by hand from thousands of pieces of lightweight nylon fabric. >> also it undergoes the stress test, just to -- well, to double check, because our supplier already checks it. but we also check it when we process them. >> reporter: hot air balloons use propane gas to heat the air that lifts them. a typical hour-long flight can use up to 100 liters, enough to drive a car more than a thousand kilometers, this means hot air ballooning is a gas guzzling sport, that's why this company