The P-harmonic boundary Δ P and the P-singular point s of a Riemannian manifold R have been shown to play an important role in the study of bounded energy-finite solutions of Δu -Pu (Nakai-Sario [7], Kwon-Sario [4], Kwon-Sario-Schiff [5]). The objective of the present paper is to establish, in terms of Δ P and s, properties of unbounded energy-finite solutions {PE-functions) and of limits of decreasing sequences of positive Pis-functions (PEfunctions). Also, PE-and PZs-minimal functions will be discussed.For the convenience of the reader we shall briefly review, in 1, some preliminaries (for details see Kwon-Sario-Schiff [5]).1. On a connected, separable, oriented, smooth Riemanniari manifold of dimension N, consider the P-algebra M P {R) of bounded Tonelli functions / with finite energy integrals Here D R {f) = \ dfA*df is the Dirichlet integral of / over R, P(^0) a given nonnegative continuous function on. R 9 and dV = *1 the volume element of R. It is known that the P-algebra M P (R) is closed under the lattice operations fl)g= max(/,g) and fΠg= min(/,g) 9 and that it is complete in the ££-topology: if {f n } is a uniformly bounded sequence in M P {R), converges to / uniformly on compact subsets of R, and E R {f n -fj -> 0 as n, m ~> oo, then f<=M P (R).By means of the P-algebra M P {R) one constructs the P-compactification Rf of R, defined by the following properties: i?J is a compact Hausdorff