I've failed to find him in any earlier Radnor census than 1861.
POWELL Henry, h, m, 60, Fmr 56a, RAD Beguildy, Penllan, /f66/p6
POWELL Charlotte, w, m, 30, , RAD Beguildy, Penllan, /f66/p6
POWELL Elenor, d, u, 10, , RAD Beguildy, Penllan, /f66/p6
POWELL Ann, d, u, 7, , RAD Beguildy, Penllan, /f66/p6
POWELL Jane, d, u, 7, , RAD Beguildy, Penllan, /f66/p6
POWELL Allis, d, u, 4, , RAD Beguildy, Penllan, /f66/p6
POWELL Mary, d, u, 3, , RAD Beguildy, Penllan, /f66/p6
Beguildy is Radnorshire's most northerly parish, so he may be in one of the neighbouring counties of Montgomeryshire or Shropshire in earlier years.