Panasonic Corp. will start offering new solar panels with a 25-year warranty, longer than the warranties other Japanese panel makers currently offer. The warranty will be offered at no extra cost for panels that will go on sale in September, according to a statement.

Sharp Corp. and Kyocera Corp. offer a free-of-charge, 10-year warranty for their panels that can be extended for fees, according to their websites. Panasonic will also start offering another set of panels that can be installed in about half the usually required time, according to the statement.