<Do massless materials absorb solar irradiation like massive materials ? > Absorb - yes. Store the energy - no. Jeff Jeff Thornton President - TESS, LLC 2916 Marketplace Drive - Suite 104 Madison WI 53719 USA Phone: 608-274-2577 Fax: 608-278-1475 E-mail: thornton at tess-inc.com Web: www.tess-inc.com