Florida Power and Light Company appeals a judgment which upheld the 1980 tax assessment of all of its tangible personal property located in Broward County. Our review of the record leads us to conclude that the appellant has not shown that the property appraiser’s method of appraisal was contrary to section 193.011, Florida Statutes (1980), nor to section 192.032, Florida Statutes, (1980), but is instead a legal tax assessment, well supported by substantial, competent evidence.

A taxpayer must carry a heavy burden in order to successfully challenge a property tax assessment. A tax assessment carries a strong presumption of validity and, in order to prevail, the taxpayer must present proof that excludes every hypothesis of a legal assessment. Bystrom, et al., v. S.F. Whitman, et al., 488 So.2d 520 (Fla.1986); Blake v. Xerox, 447 So.2d 1348 (Fla.1984); Straughn v. Tuck, 354 So.2d 368 (Fla.1977); Powell v. Kelly, 223 So.2d 305 (Fla.1969). Appellant fails to overcome this presumption. Accordingly, we affirm.