We consider a solar power supply for a LTE macro base station (BS) based on a photovoltaic (PV) panel and a battery, and we develop two discrete-time Markov chain (DTMC) models for the analysis and the dimensioning of the system elements (PV panel size and battery capacity). The DTMC models account for the solar irradiance levels in pairs or triples of consecutive days, and for the quantity of energy stored in the battery. From the DTMC steady-state (or transient) solution it is possible to derive performance metrics on which the system dimensioning can be based. We apply our models to BS locations in southern and northern Italy. Results show that the simpler model contains sufficient details for an effective system design.