Photovoltaic power plants (PVPPs) are expanding rapidly across arid and semi-arid regions, but their ecological consequences cannot be directly inferred from evidence drawn from multiple climatic zones, because ecosystem functioning in drylands is strongly constrained by water availability. We therefore conducted a dryland-focused meta-analysis of observational studies to quantify the effects of PVPPs on local microclimate, soil, vegetation, biodiversity, and greenhouse-gas-related variables. Our synthesis included 44 studies comprising 679 paired comparisons among under-panel, between-panel, and off-site control conditions. Using multilevel random-effects models, we estimated overall effect sizes and evaluated heterogeneity through subgroup analyses and meta-regression. Across studies, PVPPs were most consistently associated with reduced near-surface wind speed and air temperature, together with increased soil moisture and vegetation cover (VC). In contrast, responses of aboveground biomass, annual net primary productivity, and total phosphorus were less robust and should not be interpreted as uniform ecological responses across dryland PVPPs. Heterogeneity was partly associated with experimental position, land use type, panel type, operating time, and background moisture limitation, with aridity index and mean annual precipitation emerging as the most consistently supported continuous moderators in exploratory univariate analyses. In general, PVPP-associated increases in moisture- and vegetation-related variables, particularly soil moisture and VC, were stronger under drier background conditions. These findings suggest that, within the currently available dryland evidence base, the strongest and most consistent PVPP-associated responses are concentrated in microclimate- and moisture-related variables, whereas broader ecological responses remain more heterogeneous and tend to be more positive under drier background conditions.