Manufacturing plants in South Africa have been adopting various energy systems to meet regulatory requirements and operational needs. The study employed ethnographic methods, including interviews and observations, to gather data on manufacturing plants' energy system implementations in South Africa. A time-series forecasting model was developed to analyse historical adoption data and project future trends. A significant proportion (75%) of the sampled plants had adopted at least one new energy system by the end of the study period, with a notable increase observed in solar power installations over recent years. The time-series forecasting model accurately predicted the adoption rates based on historical data. The findings suggest that further incentives and support are needed to accelerate the uptake of advanced energy systems in South African manufacturing plants. Policy makers should consider promoting public-private partnerships for funding innovative energy projects, as well as implementing educational programmes to enhance awareness about sustainable energy solutions. The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.